Wednesday, March 13, 2013

Corbon 45 Auto +P 185 Grain DPX Gel Test

First off, I need to thank the kind blog reader that donated the ammunition for this test.  As you may know, the Corbon DPX line is in the super-premium defense ammunition price category and I am doubly grateful that anyone is willing to donate ammunition for testing with the current state of ammunition availability in the stores.

The Corbon DPX line came on the market several years ago.  I can remember the buzz it created around the various web forums when it was launched.  Rather than do a horrible job describing the ammunition line, I grabbed the description from the Corbon website.

DPX is a solid copper hollowpoint bullet that combines the best of the lightweight high speed JHPs and the heavy weight, deep penetrating JHPs. Recoil and recovery between shots are similar to the light weight rounds while soft tissue penetration is similar to the heavy weight rounds.

Hard barrier penetration on auto glass and steel are no problem for this all copper hollowpoint round. You get superb performance on these hard barriers while still maintaining safe soft tissue penetration depths.

Test Pistol Specs:
Springfield XDs 3.3" Barrel

Testing Protocol:
My testing process is pretty simple.  I take one shot at the end of a Clear Ballistics Gel block that measures approximately 6" x 6" x 16" and weighs approximately 16 lbs.  I take the test shot from 8 feet away and impact velocity is measured less than 2 inches away from the block.  Clear Ballistics Gel is calibrated to 10% ballistics gel density.  I shoot the block at the range and then bring it home to analyze the block and recover the bullet.  Immediately prior to shooting the block, I take a 5 shot velocity test over a ProChrono Digital chronograph.

Test Results:
The test results are summarized in the data sheet below along with a close up shot of the recovered bullet.

Video documentation of the entire test from range through bullet recovery is available below.  The high definition video is best viewed on YouTube, but you can also view it here.


My Thoughts on This Load:

Velocity:
As anticipated, we fell very short of the advertised 1075 fps velocity published on the box.  I place the blame for that entirely on the short barrel used for this test.   If you choose to use this load in a short barrel 45, you will probably achieve similar velocity results.


Expansion:
The DPX bullet excels at expansion.  Even with our test velocity of approximately 900 fps, we still observed complete expansion.  The recovered round had an average expanded  diameter of .7805 inches.  The expanded round was 73% larger than its original .451" starting diameter before expansion.  I included two views of the recovered bullet so you can see how uniform the expansion was around the entire circumference of the bullet. 

Weight Retention:
Along with superior expansion, the solid copper construction of the DPX bullet all but guarantees the bullet will retain 100% of its starting weight when tested in a soft gel media like we used in this test.  The recovered round measured 184.9 grains or 99.9+% weight retention. 

Penetration:
Some readers may find the 10.375" of penetration to be sub-optimal performance.  That's fine, but  we need to remember that we tested in a sub-optimal barrel length that did not allow the bullet to achieve the 1075 fps published velocity.
  
Energy:   
The calculated energy of the test shot was 333 ft/lbs, which was much lower than the 475 ft/lbs published on the box.  Again, this discrepancy is directly related to the slower velocity we observed with our short test barrel.

Wrap Up:
For the short barrel shooter, this load does a great job with weight retention and expansion.  The 3/4" wound channel left in the gel block was very pronounced due the the large amount of cutting surface on the individual hollow point petals.  Penetration came up short of the magic 12" in this test and I think that result was consistent with the slower than specified velocity observed in this short barrel 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.

9 comments:

  1. The more I see your tests with this short-barreled .45, the less interested I am in buying a short-barreled .45!

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  2. From what I understand, the FBI insists on the deeper penetration in case a combatant is hit from the side and the round has to penetrate an arm before entering the torso. This is probably less important for the average Joe than for the FBI. 10 inch penetration for a straight on torso hit should be more than adequate.
    As far as the effectiveness of a short barrel .45 per the reply above, I'll stake my life on a short barrel .45 above just any smaller diameter, faster round any time.
    Thanks to the benefactor who donated this ammo for the test and most of all thanks for all this rest data on the various brands of ammo. I find it very informative and fascinating.

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    1. Thanks for the comment. I find it fascinating too and it's been quite a journey from wet phone books in the 90's to this new clear gel that's available today. Nice to know you find the tests to be interesting too.

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    2. If your not a dyed in the wool .45 guy who can appreciate different calibers for their strengths as well as being a goal oriented (not gear oriented) person who understands the need for penetration-

      I'd go with a short barrel .40 over a short barrel .45.

      The reason is because the .45acp was designed for a 5" barrel,the .40 was designed around a 4" barrel,and has higher operating pressures.This translates to better ballistics from shorter barrels.

      A 180gr .40 at around an estimated 1000fps from a theoretical 3.5" barrel will have greater sectional density,higher impact energy,and thus greater penetration then a 185gr .45 slug going 100fps slower.

      Not knocking .45,but for short barrels I have to say that this is where .40 comes into its own.I wouldn't want a weapon chambered in .45acp to have anything less then a 4" tube,and thats still pushing it.

      That corbon DPX is a top tier load for .45acp otherwise.

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    3. .40 is a good round but it has punishing recoil in light weight firearms. I believe that quality .45 loads will still have good performance out of the Glock 30/36 platform without the sharp snap of a .40 in a Glock 27. I've noticed that for me personally I can shoot a Glock 30 faster and more accurately than a Glock 27 or even a 26 and still conceal it well. If you can shoot a .40 in a small gun well and the recoil doesn't bother you then by all means carry a .40. Keep in mind that in a gun fight shooting from unconventional positions is probably more likely than not, such as one handed from your weak hand from behind cover, and you don't want a firearm that will slide around in your grip. For me that’s a Glock 30S in .45 caliber.

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  3. I have to agree that the .45 in a short barrel is a combination that is just not cutting it.

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  4. I have to say, I disagree with the above comments. Speer Gold Dot Short Barrel has been shown in independent too penetrate 13" to 15" and expand to 0.65" to 0.7". I would take those numbers.

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  5. My Colt officer s loaded with the 185 and I feel they will work if needed . I wanted a round that would get over 900FPS. to assure reliability from the short barrel. DPX fills that and good expansion

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