Friday, November 29, 2013

The Continuing Evolution of Terminal Ballistics Testing - A Guest Blog by Charles Schwartz

I've been fascinated by terminal ballistics testing since the early 1990's when I first started reloading.  Back then, we received new phone books each year and I was "that guy" who would sweep through the neighborhood asking for the old phone books so they could be "recycled".  By recycled, I really meant they would be soaked in my bathtub and subsequently shot at the range.  Over several years, I caught many bullets in those hydrated phone books, developed some awesome handloads, and learned that not all bullets were created equal.  I really enjoyed the load development and testing, but eventually had to stop due to other life priorities.

Fast forward to 2009.  The pocket pistol boom is in full swing and I catch the bug.  I start looking for terminal performance data for these short barrel pistols and find very little information is available.  I quickly came to the realization that if I wanted terminal performance information, I'd better start tracking down phone books again.  Since 2009, I've progressed from phone books, to water jugs, a failed attempt to create an aqueous media bullet trap, SIM-TEST, and finally Clear Ballistics Gel.  About two years ago, I started sharing my test results on the blog.  Some of the early tests are embarrassing to view now, but I've done my best to constantly improve the quality of the data I capture, and implement the suggestions from readers viewing the tests.  One of those suggestions was to cross validate my terminal performance results with the Soft Tissue Ballistic Penetration Model found in Charles Schwartz's book titled Quantitative Ammunition Selection.

When I transitioned from SIM-TEST media to the Clear Ballistics Gel last year, skepticism ran high that this virtually clear, temperature insensitive, reusable gel could really be a suitable substitute for 10% Ordnance Gel.  Fans of the Schwartz book would frequently check my test results vs. the Soft Tissue Ballistic Penetration Model and let me know that the results in line with the model.  This was a confidence booster for me and I always thought I should locate a copy of the book to see what this model was all about.  Last month, I received an iPad for my birthday so I downloaded the Kindle reader app and purchased the Quantitative Ammunition Selection book from Amazon.  As I was puzzling through how to integrate the model into my data sheet, I received an unexpected email from Charles Schwartz.  (long story how this unexpected contact happened not suitable to cover now) We’ve been working together over the last two weeks and he’s agreed to explain a bit more about the models in his Quantitative Ammunition Selection book and also the specific metrics I will be adding to my data sheet going forward.  With that, take it away Charles!


Since I’ve long been a fan of Bruce’s work, especially as it relates to his ammunition tests conducted in the Clear Ballistics Gel test medium, I could not help but feel more than a little honored when he asked me to write a guest article for his blog.

     And why not?

I am tremendously impressed by the range of his work and the considerable database of Clear Gel tests that he has amassed. I believe that Bruce’s work stands as strong indication that eventually synthetic test mediums such as Clear Gel will offer the promise of conducting valid, scientifically-repeatable terminal ballistic tests without the attendant annoyance and expense associated with testing in calibrated ten percent ordnance gelatin. Imperfect as it is at this early time, I believe that Clear Gel, and the general class of synthetic soft tissue surrogates known as PAGs (physically associating gels), has great potential in the field of terminal ballistic testing once the material technology matures. Once the material properties of PAGs are improved through R&D to the point that they are able to more accurately represent the formation and cyclic duration of the temporary cavities produced by both high- and low-velocity projectiles, I suspect that PAGs will become more widely accepted and rapidly supplant calibrated ordnance gelatin as the soft tissue simulant of choice due to its superior transparency and insensitivity to ambient temperature.

     So, what’s the common interest here?

Well, that’s easy enough to answer. Bruce and I have both gone about pursuing it in different ways, but our ultimate goal is the same. We both want to see the process of terminal ballistic testing made easier and more affordable for the “average guy” without sacrificing validity in the process. Accessibility and accuracy; that’s the goal. Seeing the need for a new process, or a means of updating an old process, is exactly what each of us, in our own way, has been striving to achieve. This, of course, brings me to the discussion of the way that I addressed what I saw as a need for an approachable mathematical model that eliminates the guesswork necessary (until now) when using water as a terminal ballistic test medium.

Water, just like Clear Gel, is an isotropic substance (that is, it is “the same” in all directions) that is insensitive to ambient temperature and has the added benefit of requiring no calibration in order to produce valid test results. So long as the water has not frozen solid or come to a boil, it will produce nearly identical forces to those that arise in calibrated ten percent ordnance gelatin upon bullet impact. Those forces, related to the speed of sound within the test medium and the density of the test medium, are what determines how the bullet and test medium will interact with one another and the more similar they are, the better their respective behavior will correspond to one another. For the sake of comparison, the speed of sound in water at room temperature is approximately 4,910 feet per second, which corresponds closely to that of the speed of sound in calibrated ordnance gelatin at 4,901 feet per second. The densities of both water and calibrated ten percent ordnance gelatin are also very close to one another at 0.999972 gram per cubic centimeter for water at room temperature and 1.040 gram (± 0.200 gram) per cubic centimeter for ordnance gelatin at 39.2° Fahrenheit.

While water produces expansion rates and bullet weight retention nearly identical to that of calibrated ten percent ordnance gelatin, the one drawback with testing in water is that it does not allow for the proper representation of a bullet’s maximum penetration depth as it occurs in other soft tissue simulants without the use of a penetration depth “conversion factor”. Many of these “conversion factors” exist. Ranging in magnitude from 1.8 to 3.0, these factors see common use, and occasionally, bitter debate, in the self-defense and firearms enthusiast communities. However, the problem inherent with the use of these factors is that no correlative study exists that confirms the validity of any of these values.

Of course, such modeling has been attempted before and more than once, but the problems with these prior attempts are manifold. Some attempts at modeling terminal ballistic performance are simply too subjective or are poorly defined. That is, they are composed of otherwise meaningful physical variables that have been cobbled together, often haphazardly, in the hope that some significant perspective or interpretation might be gained from them. Other models, while capable of producing highly correlated, objective, dimensional results, are simply too esoteric for the average firearms enthusiast’s or concealed weapons carrier’s use because they either rely upon advanced mathematics far beyond the reach of the “average guy” or because they are presented in such a manner as to make them unreachable for all but a few.

     Fortunately, it doesn't have to be this way.

The solution to this issue is to produce a mathematical model of high correlation that accurately predicts penetration in soft tissue simulants like calibrated ten percent ordnance gelatin using water as the test medium while still remaining accessible to the "average guy". Of course, that is easier said than done, but that is where Quantitative Ammunition Selection comes to the fore. The mathematical model found in Quantitative Ammunition Selection relies upon a governing expression; a proportionality of high correlation to a population of 735 calibrated ordnance gelatin test data obtained from no less than ten independent, published, and unpublished sources composed of various ammunition manufacturers, laboratories, and law-enforcement agencies. The QAS model, a predictive instrument, which has a correlation of r = 0.942 when compared against those 735 data, possesses a margin of error of ± 1.00 centimeter at a 95% confidence margin when using water as a terminal ballistic test medium. The QAS model’s yields are expressed in units of length (in centimeters or inches) for maximum terminal penetration and mass (in grams or ounces) for permanent wound mass equivalent as these effects would occur calibrated ten percent ordnance gelatin where ordnance gelatin (or soft tissue) is penetrated and permanently crushed through direct contact with the bullet. Using the QAS model, it then becomes possible to make an “apples to apples” comparison of maximum penetration depth and permanent wound mass in tangible units of length and mass between different calibers, bullet weights, and designs; it’s something that only one other model offers, but that one in particular is hardly accessible to the “average guy”.

Of course, there is a procedure for conducting terminal ballistic tests in water. Many people make the unknowing, but completely understandable, mistake of using plastic jugs and containers of all sorts without considering the confounding factors that they are introducing into the process. After all, how else does one confine water so that a bullet can fired into it?

The problem with such a practice is that plastic jugs and containers come in all shapes and sizes and, more to the point, are made of all sorts of different materials having different thicknesses and physical properties. Plastic jugs, often used in such testing, are made from various polymers such as polypropylene (PP), low-density and high-density polyethylene (LDPE and HDPE), polyethylene terephthalate (PET), and polyvinyl chloride (PVC) to name just a few of the materials in common use today. Moreover, plastic jugs often have variable wall thicknesses in their design that vary significantly in strength depending upon their construction and the material from which they are made. These material properties can, and do, influence the expansion rate and weight retention of bullets passing through them, which in turn, can lead to an inaccurate and misleading representation of a bullet’s terminal ballistic performance.



Instead, the best approach is to use a container with the least dimensional variance in its construction and the lowest material strength available. That ‘ideal container’ is the cheapest generic re-sealable one-gallon freezer storage bag that you can find, with “cheaper” being “better” as a general rule.

     So, why is “cheaper” better?

Well, because any manufacturer seeks to reduce production costs first through the reduction of material used to manufacture a product, the cheapest re-sealable one-gallon freezer storage bags tend to offer the thinnest, most consistent, container wall possible made of the relatively weak polymer, low-density polyethylene (LDPE). It is a material, so fragile and so thin that you can, with very little effort, push your finger right through it. Try that with a two-liter soda bottle made of PP or PET or a one-gallon milk jug made of HDPE and the effects of these different materials becomes quite apparent. Because re-sealable one-gallon freezer bags are the same thickness throughout their construction (except at the point of closure which is no big deal), they also offer the most consistent test results regardless of where bullet impact occurs, another point solidly in their favor.

Once a bullet being tested has been fired and recovered from the water-filled one-gallon freezer bags, it is necessary to record the data obtained for use in the QAS mathematical model. Velocity at impact, average expanded diameter, and retained weight are entered into the QAS model and the maximum penetration depth in calibrated ten percent ordnance gelatin is predicted. After that, the predicted maximum penetration depth is then used to determine the mass of the permanently damaged soft tissue present within the permanent wound cavity and the exit velocity of the projectile from any thickness of test medium, if that is desired. Because Clear Gel possesses physical properties that are extremely close to those of calibrated ordnance gelatin, the QAS model can also be reasonably assumed to predict terminal ballistic behavior in Clear Gel ballistic test medium.

To illustrate this point, one needs to look only as far as Bruce’s most recent test of the Federal 9mm ‘Tactical Bonded’ 124 gr. JHP (LE9T1) in the Clear Gel test medium.

In the first part of that test, a single Federal 9mm 124 gr. ‘Tactical Bonded’ JHP was fired into a bare block of Clear Gel ballistic test medium. The 9mm JHP struck the test block at a velocity of 1,110 feet per second, expanded to an average diameter of 0.5955 inch, retained over 97% of its initial weight, and penetrated to a depth of 11.625 inches before coming to rest in the Clear Gel test block. Comparing the data produced by this test to the predictions made by the QAS model indicates that the QAS model’s prediction is in strong agreement with this particular test result, predicting a maximum penetration depth for this test of 11.478 inches in the Clear Gel test medium.

In the second part of that test, two shots fired through the IWBA four-layer heavy denim barrier, exited the end of the 16-inch long Clear Gel test block so a concrete value doesn’t exit for those tests. Fortunately, it is possible to predict their respective penetration depths and permanent wound cavity masses using the QAS model, thereby “saving” the tests. In this case, the first test bullet struck the test block at a velocity of 1,095 feet per second after passing through the IWBA denim test barrier. It expanded to an average diameter of 0.494 inch, retaining all of its weight before exiting the end of the test block. Entering the available data into the QAS model, the model predicts that the test bullet would have continued for another 1.293 inches before coming to rest at a maximum penetration depth of 17.293 inches. The second test bullet struck the IWBA denim test barrier and entered the test block at a velocity of 1,116 feet per second, expanded to an average diameter of 0.4865 inch, and retained 99.9% of its original weight before leaving the end of the test block. Using the available data, the QAS model predicts that the test bullet would have continued for another 1.981 inches before coming to rest at a depth of 17.981 inches.

The QAS model is also capable of predicting the residual velocity (or exit velocity) of the two test bullets as they left the 16-inch long Clear Gel test block. The QAS model predicts that the first test bullet fired through the IWBA denim barrier would have had an exit velocity of 122.068 feet per second and a residual kinetic energy of 4.125 foot-pounds meaning that it would likely not pose a significant physical threat to a bystander located immediately downrange. The QAS model predicts that the second test bullet fired through the IWBA denim barrier would have had an exit velocity of 152.984 feet per second and a residual kinetic energy of 6.438 foot-pounds meaning that it also would likely not pose a significant physical threat to a bystander immediately downrange. Both test bullets expended approximately 86% – 88% of their available kinetic energy within the target rendering them unlikely to produce a lethal down-range threat and, in the process, demonstrating the advantage of using a JHP (when they expand, that is) for self-defensive use.

As illustrated above, one of the benefits of using the QAS model is that it can be used to confirm a test result or, in the case of a test bullet exiting the test medium unexpectedly, to “save” the test by using the available data (impact velocity, retained mass, average expanded diameter) to predict the terminal performance of the otherwise “compromised” test event. Since I wish to substantiate this opinion further than I have in this article, I am extremely interested in conducting a detailed statistical analysis of Clear Ballistics Gel test data in order to determine just how closely the QAS bullet penetration model correlates to actual terminal ballistic behavior in that test medium. I hope to share the results of that analysis later.

Quantitative Ammunition Selection is available domestically and internationally in hardcover, paperback, and eBook formats and may be purchased at www.quantitativeammunitionselection.com . Just select the appropriate link found on the lower third of the ‘Home’ page for the format that you want.

-Charles Schwartz

Thanks very much Charles for taking the time to explain the background of the new metrics I will be adding on all future test reports.  I think it's important that readers fully understand the science behind the new metrics and what they represent.  Additionally, I'm looking forward to sharing my past and future test results with you so together we can continue to improve the quality of information generated by my testing, as well as others who wish to undertake their own terminal ballistics testing.

Thursday, November 28, 2013

Black Friday Sales

Happy Thanksgiving.  Last year I trolled through my email and picked out a few Black Friday Deals that I thought I would  pass along.  This year some of the discounts are even better than last year.  I like these discounts because they are blanket across the store promotions and not just on selected items.

Remora Holsters - 40% off and free magazine holster.  Code: SALE40    Ends 12/2/2013

Clear Ballistics - 30% off all products.  Code:  BlackFriday     Ends 12/2/2013

Comp-Tac Victory Gear - 20% off your online order.  Code:  BLK-2013    Ends 11/29/2013


Looks like I'll be sitting down and working out some orders later today.


Sunday, November 24, 2013

How-To Polish the Feed Ramp of Your Semi-Auto Pistol

If you've ever had the chance to look at the feed ramps of several barrels, you may have noticed that they come in many different shapes and sizes.  They all fill a key role in the reliable operation of a semi-auto pistol as they help guide rounds from the magazine into the chamber of the barrel.  Some firearm manufacturers will polish the feed ramp and others ignore the ramp and leave it full of machining marks.  It's all a trade-off of the cost to polish the ramp vs. the enhanced feeding reliability of the pistol.  I've seen barrels with feed ramps full of deep machining marks that function really well.  I've also seen pistols with ugly feed ramps that cause feeding issues where the bullet jams into the feed ramp and causes a failure to feed.  

If you have a barrel with a rough feed ramp, and it's impacting the feeding reliability of the pistol, here is a very low impact way to go about polishing up the feed ramp.  I'm a bit OCD when it comes to cleaning my pistols so I do this polishing process with the Lone Wolf barrels to make them easier to clean.  Before polishing, it's not uncommon to see copper deposits on the feed ramp as shown in the photo below.
 

In the photo below you can see that the Lone Wolf barrels come with a buffed finish on the stainless steel that leaves a pattern of very fine scratches across the feed ramp.  Do they work well with this finish?  Yes they do.  Are they more difficult to clean?  Yes they are.  For this reason, I like to remove the factory finish and replace it with a high polish.


It's been some time since I made a how-to video so I decided to make one that demonstrates a low impact, and low risk, way to get a mirror smooth finish on your feed ramp without using aggressive abrasive papers or power rotary tools.  When taking on a project like this, there is always a risk of going too far and removing too much metal from the feed ramp.  This risk increases exponentially if you use very abrasive compounds or papers.  This method is not the fastest or most effective way of achieving the end result, but it's a good practice exercise for those of us that don't mind investing a little time developing a skill that can be used anywhere on a pistol that can benefit from a highly polished surface.  The only tools you need are your hands, a tube of Flitz or tub of Mother's Mag & Aluminum Polish, and a bunch of Q-tips. 

  
Here are the barrels I started with.

Here are the barrels after investing a couple of hours polishing the ramps.  It's a dramatic improvement.  Not up the quality of work you would get from a professional Gunsmith, but it is a serviceable result.  

If you attempt this, please make sure to clean your barrel before and after polishing.  It's not difficult to end up with some polish residue in the chamber when you are done.  You will want to be sure the chamber and barrel are free of all polishing residue before using the barrel.

Wednesday, November 20, 2013

Remington UMC 357 Sig 125 Grain JHP - 3 Pistol Denim and Gel Test


I'll start with a big Thank You to Ammunition Depot for supplying the ammunition used for these tests.  In addition to their ad at the top of the page, Ammunition Depot has been a generous supporter of many ammunition tests published over the last 12 months so please check them out if you are shopping for ammunition.

Remington UMC ammunition is a staple ammunition product that can be found in a multitude of retail locations.  The familiar green, white, and black packaging may not be as sexy as other ammunition choices on the shelf, but it is the ammunition in the box that really matters.  I've always found Remington UMC ammunition to be well crafted and reliable in the pistols I've used it in.  For shooters on a budget, the 50 and 100 count boxes are reasonably priced which allows you to shoot more while spending less.

If I had an unlimited amount of time available to focus on terminal testing, I would definitely follow the format of this test more often.  I think there are some new insights to be gained by looking at terminal performance across a range of velocity and not just the results from a single test shot.   

Test Pistols:

Test Protocol:
Step 1)  Measure and record temperature and relative humidity.
Step 2)  Run a 5 shot velocity average over a ProChrono Digital Chronograph at a distance of 10 feet.
Step 3)  Run test shot through 4 layers of 14 oz/yard heavy-weight denim and into a block of Clear Ballistics Gel that is calibrated to 10% Ordnance Gel density.  Shot distance is 10 feet.
Step 4)  Run a 600 fps calibration test bb shot into the Clear Ballistics gel block and record penetration depth.

Test Results:

Service Length

Compact

Subcompact


Video Documentation of the Entire Tests from Range to Bullet Recovery:

Service Length

Compact

Subcompact

My Thoughts on This Load:
Overall, I was very happy with the way this test worked out.  I did my best to minimize the variables across all 3 barrel lengths by using the same denim and gel block for all 3 tests.  The one disappointment was that all 3 bullets passed entirely through the gel block and came to rest against the phone book backer.  Because of this, I feel the expanded diameters of the recovered rounds are good approximations, but not firm data points since petals may have been flattened when the bullets made contact with the phone book.  At least we learned that they all expanded to some extent.

The photo below is a value add for the people who read the blog.  Folks viewing only the YouTube videos won't see this view.  By turning the block 90 degrees,  the photo below shows the top down view of the gel block and allows for quick visual comparison of the wound channels created by the 3 test shots.  They all look relatively similar, but there were some differences in the points at which expansion started and the length of the stretch cavities.  I've been doing some outside reading and the experts like to see expansion cavities that run for several inches in length.  Finding those artifacts in the gel block indicates the bullet was still traveling at a velocity great enough to reach and damage vital organs located several inches deep in the target.   

I also also pleased to see expansion with all three test shots.  The denim barrier didn't seem to have a significant impact on expansion.  I think the primary differences with expansion were velocity related.  As velocity increased, more of the lead core flowed out and down the jacket petals.  I saw no evidence of the undesirable separation of the lead core and copper jacket with any of the test shots.  The photo below shows all three recovered rounds with the fastest on the left and the slowest on the right.  When you lay all 3 recovered rounds side by side you can really see the difference a little extra velocity makes with this load.

Pick or Pan:
Some may think that 18+ inches of penetration is too much penetration.  Others may find this perfectly acceptable.  I appreciated the consistent expansion performance and limited velocity difference across the range of barrel lengths tested.  Add to that the reasonable retail price and wide availability of this load and I would call this one a pick.  It may not be the best performing load available, but it is a consistent performer.   



Disclaimer....This test should not be considered an endorsement or recommendation for the product(s) tested.  All tests represent actual performance in ballistics testing media.  Terminal performance in all other media will show different results.  It is up to each individual to make their own personal decision on which specific ammunition to use for their needs.  It's also critically important to test any ammo in YOUR SPECIFIC FIREARM before relying on it for any purpose.

Ammunition labeled as +P or +P+ should only be used in firearms that have been certified by the manufacturer as safe for the additional pressures generated by these ammunition types.

Monday, November 18, 2013

Boberg XR45-S Now Available for Pre-order

This is what we have been waiting for.  As seen on the Boberg Arms website and also their Facebook Page.  It's just a pre-order queue at the moment, but it's one step closer to reality.  We also have a price now.  The pre-order form isn't where you would expect it to be under the Products tab with the rest of the current production pistols.  You have to click through their Webstore to get to the pre-order form.  Jump in the queue and start saving your lunch money.



Arne is fond of overlay drawings for comparison sizes.  Here's the latest vs. the Kahr PM45.  I'd like to see one comparing the XR45-S to the Springfield XDs 45.



Additional pistol specifications can be found on my previous post about the XR45-S.

Saturday, November 16, 2013

Remora Holsters New Bra Draw Holster

If you follow the blog, you know I'm a fan of Remora Holsters.  In my opinion, they offer exceptional value and function for your money.  Over the last two years, I've watched intently as Alan Bogdan and his crew in Naples, Florida churn out new holster designs at break-neck speed.  It's been a challenge to keep up with them.  Earlier this morning I received an email from Remora announcing their current promotion (30% off all standard IWB holsters) no coupon code required, and a sneak peek at their latest innovation the Bra Draw holster.


Obviously, I had to watch the YouTube demo video and was surprised that the demo gun appears to be a Kahr PM series sized pistol, which is actually on the large side of the micro pistol universe.  The ease of reholstering also caught my attention.   


As of now, the new holster has not been added to the Remora Holsters website.  I'm sure more information will be available soon.  If you are looking for a pocket, leg, IWB, OWB, IWB tuckable, and now bra holster, Remora has a holster solution for you.

Thursday, November 14, 2013

Buffalo Barnes 9mm +P+ 115 Grain TAC-XP Denim and Clear Gel Test


I want to thank blog reader Ben S. for donating the box of ammunition used in this test.  If you didn't know, Buffalo Barnes ammo is really expensive and a box of 20 will run you about $37.00 plus shipping.  Ben was nice enough to send along an entire box for testing.

Buffalo Bore has an extensive line of Lead Free ammunition that replaces traditional lead and lead core bullets with solid copper projectiles manufactured by Barnes Bullets.  Buffalo Bore labels this ammunition line as Buffalo Barnes.  The Barnes bullet used in this load is the TAC-XP bullet which Barnes describes as; "Designed for law enforcement and personal defense, 100-percent copper TAC-XP™ pistol bullets meet the requirements of lead-free practice environments. They maintain their original weight and track straight after being fired through intermediate barriers like car doors, plywood and automobile windshield glass."

The specific load tested is Buffalo Barnes Item 24H.  I made an error on the data sheets and listed the bullet as DPX.  As mentioned above, it's actually the Barnes TAC-XP bullet.  Corbon uses the Barnes TAC-XP bullet in their DPX ammunition line.  I'm actually surprised I don't make errors like this more frequently. 

Test Pistol:


Test Protocol:
Step 1)  Measure and record temperature and relative humidity.
Step 2)  Run a 5 shot velocity average over a ProChrono Digital Chronograph at a distance of 10 feet.
Step 3)  Run first bare gel test shot into a block of Clear Ballistics Gel that is calibrated to 10% Ordnance Gel density.  Shot distance is 10 feet.
Step 4)  Run second test shot through 4 layers of 14 oz/yard heavy-weight denim.  Shot distance is 10 feet.
Step 5)  Run a 600 fps calibration test bb shot into the Clear Ballistics gel block and record penetration depth.

Test Results:


Video Documentation of the Entire Test from Range to Bullet Recovery:


My Thoughts on This Load:
In general, I'm not a big fan of +P+ loadings because they don't fit neatly in the SAAMI specification and can be unsuitable or dangerous for use in many pistols.  If you decide to try some of this ammunition, please be sure your pistol is capable of handling the high chamber pressures generated by this load, or any load designated as +P+.  It's always best to consult your owner's manual or contact the firearm manufacturer if you are unsure.

I was actually surprised by the velocity numbers recorded during this test since they were quite a bit lower than those published by Buffalo Bore on their website.  It could be that the Lone Wolf 9mm conversion barrels I used in the test pistols were the cause of the difference, or maybe this load has been dialed down a bit on velocity and pressure since the information went up on the website.

Overall, I thought the terminal performance was outstanding with full expansion and penetration between 15 and 16 inches on all test shots.  The 4 layers of heavy denim barrier had no significant impact on terminal performance.

Pick or Pan:
Based on terminal performance, this load is one of the best performing 9mm rounds I've tested.  If it was loaded within SAAMI pressure specifications, and priced so I could afford to practice with my carry ammo, I would add this load to my short list of 9mm picks.   

Bonus Bare Gel Blitz Test with 4 Inch Barrel:




Disclaimer....This test should not be considered an endorsement or recommendation for the product(s) tested.  All tests represent actual performance in ballistics testing media.  Terminal performance in all other media will show different results.  It is up to each individual to make their own personal decision on which specific ammunition to use for their needs.  It's also critically important to test any ammo in YOUR SPECIFIC FIREARM before relying on it for any purpose.

Ammunition labeled as +P or +P+ should only be used in firearms that have been certified by the manufacturer as safe for the additional pressures generated by these ammunition types.

Friday, November 8, 2013

Boberg XR45-S Development Update

Last March, I posted a story about the next potential pistol from Boberg Arms.  While similar to the XR9-S and L 9mm pistols, Arne is upping the power factor and building a 45 Auto this time around.  From the previously released drawings, we learned that the XR45-S will have the following specs:
Length is about 5.75"
Height is about 4.4"
Width is about 1.084
Slide width is about 1.084"
Capacity is 6+1
Barrel Length is planned at 3.7"
Length is about 5.75"
Height is about 4.4"
Width is about 1.084
Slide width is about 1.084"
Capacity is 6+1
Barrel Length is not shown on the drawing, but Arne said 3.7" - See more at: http://mousegunaddict.blogspot.com/2013/03/a-sneak-peek-at-boberg-45-acp-xr45-s.html#sthash.SU64THIP.dpuf

Arne Boberg treated us to a rendering of the XR45-S last week.  Aside from the markings on the slide, it would be difficult to tell the 45 Auto from the 9mm.  

He also posted two pictures of the new 45 Auto magazine displayed next to the current 9mm magazine.   The difference is more obvious in this case. 

I think it's really cool that Arne posts stuff like this on his Boberg Arms Forum.   I'm  not sure how many other manufacturers let you be an insider as they progress through the process of building a new gun.  If you aren't a forum person, you can always follow Boberg Arms on their Facebook Page.

Monday, November 4, 2013

CORBON 9mm +P 125 Grain Denim and Clear Gel Terminal Test


Many thanks to Ammunition Depot for supplying the ammunition used for this test.  I buy most of the ammunition used for testing, but generous donations like this really help me cover a much broader assortment of ammunition available in the marketplace.

Over the last two years that I've been publishing terminal ballistics testing reports, I've tested a few CORBON products.  Most of the tests have been with 380 Auto, 32 Auto, and 32 NAA.  I've always found CORBON ammunition to be well made, fast, and priced at a premium to most other similar loads.  This test was my first opportunity to see how their traditional 9mm jacketed hollow points would perform.

Test Pistol:

Test Protocol:
Step 1)  Measure and record temperature and relative humidity.
Step 2)  Run a 5 shot velocity average over a ProChrono Digital Chronograph at a distance of 10 feet.
Step 3)  Run test shot into bare gel.  Shot distance is 10 feet.
Step 4)  Run test shot through 4 layers of 14 oz/yard heavy-weight denim.  Shot distance is 10 feet.
Step 4)  Run a 600 fps calibration test bb shot into the Clear Ballistics gel block and record penetration depth.

Test Results:
 
Video Documentation of the Entire Test from Range to Bullet Recovery:


My Thoughts on This Load:
There were some interesting things that came out of this test that I wanted to share with you.  I really didn't notice them when I was producing the video so consider these value added items exclusively for blog readers.

As I was analyzing the high speed video footage, I found this one frame very interesting.  I believe this is the first time I've captured the shock wave preceding the bullet and also the bullet on video.  At 480 frames per second, getting this shot was pure luck.  I wish the resolution was better, but this is as good as it gets with a $300 high speed camera.

The next image will show you a possible reason why this load performed so well in the 4 layers of heavy denim test.  I've seen these cookie cutter circles of denim in previous tests, but none have been as perfectly cut as these.  My theory is the jacket extending slightly forward of the lead core cuts the circle.  Hydraulic pressure pushes the denim down into the hollow point cavity.  The cavity is quite deep so even with 4 circles of denim, the nose of the bullet still starts to expand outward and form the mushroom shape. 

I was very pleased with the performance of both test shots.  The bare gel shot was fully expanded and almost flat.  You could make the argument that it may have expanded too much.  The heavy denim test shot also expanded, but you can see how the denim plug in the center of the hollow point cavity kept the bullet from expanding as deeply down the bullet shank.  Both test shots penetrated to a depth between 12 and 18 inches and retained 99% of their initial starting weight.  

Pick or Pan:
The 4 layers of heavy denim test protocol is a formidable barrier.  Since moving from 2 layers of medium weight denim to 4 layers of heavy denim, I've had a significant increase in the number of expansion failures.  This barrier didn't seem to pose a problem for this bullet at the tested velocity.  Based strictly on terminal performance, this load is a pick.     



Bonus Blitz Test Video with 4" Barrel Bare Gel Test:




Disclaimer....This test should not be considered an endorsement or recommendation for the product(s) tested.  All tests represent actual performance in ballistics testing media.  Terminal performance in all other media will show different results.  It is up to each individual to make their own personal decision on which specific ammunition to use for their needs.  It's also critically important to test any ammo in YOUR SPECIFIC FIREARM before relying on it for any purpose.

Ammunition labeled as +P or +P+ should only be used in firearms that have been certified by the manufacturer as safe for the additional pressures generated by these ammunition types.