Thursday, March 28, 2013

Sellier and Bellot 25 Auto 50 Grain FMJ Gel Test


I'm working in uncharted territory with this test so please excuse me if I get a bit wordy or if I deviate from the usual ammunition test format.  Some of you may know that Pocket Guns and Gear was originally named Mouse Guns and Gear when it launched in 2011.  At the time, I had been totally enamored with the small pistols, and the ammunition that went into them, for several years.  I never did dabble with anything smaller than 32 Auto when I was getting my feet wet with mouse guns, so as the blog grew I decided it was time to see how the 22 LR and 25 Auto did in basic ballistics tests.

Late last year, I was offered a mint pair of used pocket Berettas in 22 and 25 that I snapped up for use as test pistols.  I grabbed a fresh block of Clear Ballistics gel, some ammo, and my new brace of Berettas intent on doing some baseline terminal testing with them since there seemed to be a general void of structured terminal testing information with these small pocket pistols.

Test Pistol Specs:
Beretta 950BS 2.4" 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:
Since this was my first time ever shooting a 25 Auto, I don't have a solid base of information for many comparisons within the caliber.  As I was pulling my thoughts together on what I wanted to convey in the test recap, I had some ideas that might help you visualize how tiny the 25 Auto really is and why it performed as it did in the gel block.


The first thing I noticed about the recovered bullet was the bullet length to diameter ratio seemed quite different than the 32 and 380 fmj previously tested.  I'm compelled to describe the bullet as long and thin when compared to the 32 and 380 with their short and fat bullet profiles.  I have to believe the profile of the bullet contributed to the tumbling we observed in the gel block.  The picture below is more humorous than helpful.  I perched the recovered bullet on a 45 ACP Winchester Ranger T and the bullet diameter isn't even as large as the hollow point cavity of the 45 bullet.


The velocity of this load is quite slow compared to anything previously tested.  It was unfortunate that the gel tested shot went out at 40 feet per second less than the 5 shot velocity test average.  I actually had to shoot twice before I captured  a bullet.  The first shot was faster, but quickly veered out of the gel block and was not recovered.  To give you some perspective on how slow this is, I use a compressed air bb rifle to periodically test the density of my gel blocks to assure they stay calibrated with 10% ordnance gel specifications.  7 pumps on the bb rifle gets the bb moving at just over 600 feet per second.  If you shoot the tested round at a target 10 yards away, you can actually see the bullet in flight.  That's the kind of speed we are talking about this with load.

Slow velocity has a direct and exponential effect on the miniscule 41 ft/lbs of bullet energy observed in this test.  This test was a great reminder of how muzzle energy is calculated.  By the formula, you half the weight of the bullet and square the bullet velocity.  If the bullet weighed 100 grains our ft/lbs of energy would double to 80 if velocity stayed constant.  If we could somehow double the velocity to 1200 fps, our energy would quadruple to 160 ft/lbs with the 50 grain bullet.

And therein lies the challenge with the 25 Auto.  It wasn't very long ago that the 25 Auto was considered the smallest modern center fire pistol caliber in the world.  Recent additions of the FN 5.7 and 22 TCM have displaced the 25 Auto as the smallest caliber center fire, but both the FN 5.7 and 22 TCM are bottle necked cartridges with more powder capacity than the straight walled 25 Auto so they should be excluded from comparison.  In my opinion, the 25 Auto compares most closely with the 22 Long Rifle rim fire cartridge.

A 22 Long Rifle, shot from a similar barrel length, will produce substantially more velocity with a bullet that is lighter than the 25 Auto.  Since velocity contributes more to overall energy, the resultant muzzle energy will be greater with the 22 Long Rifle.  Now if you go back to mid 2012 when ammunition prices were stable, 25 Auto ammunition would cost about 4 to 5 times more per round than 22 LR.  Prior to doing a terminal test, the only real advantage of the 25 Auto over the 22 Long Rifle was in the general belief that center fire priming systems are more reliable than rim fire priming systems.  

The real eye-opener for me came when reviewing the artifacts left in the clear gel block.  One test isn't enough to establish a repeatable and predictable pattern, but it was very interesting to see the permanent bullet track left by the tumbling 25 Auto bullet between 2 and 7 inches deep into the block.  I was also quite surprised to see a total penetration depth of 10.5" even after the bullet tumbled 180 degrees on the trip down the gel block.

I will definitely continue testing 25 Auto as more ammunition becomes available again and I can get my hands on some different grain weights and bullet types.  I'm really looking forward to seeing what other surprises the little 25 Auto shows us in future tests.



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. Have you seen the Tactical Life page about the Mossads use of the .22lr?

    http://www.tactical-life.com/tactical-weapons/israeli-mossad-22-lrs/

    I'd prefer a .22lr to .25acp any day.......

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    1. Interesting read. Thanks for the link.

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    2. YVW.

      Thanks for adding to the depth of information available on the web with your blog!

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  2. That velocity was REALLY down. Why do you think that is? Could the barrel of that gun have corroded due to improper storage? That's strange. I wonder what an extra 100fps would do.

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    1. I'm afraid that's going to be normal velocity from the 25 Auto in the short Beretta barrel. I've got some Fiocchi that I can use for comparison.

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    2. Did you ever get a chance to velocity check the other ammo? I double checked Steve's pages and brass fetcher and both achieved higher V out of the same barrel length. It seems to be hit or miss with the .25 guns. You also know about bmcgilvray, whose newer .25 was dramatically more powerful than his first. He also achieved 800fps from his Beretta. Don't ask me why I want so much to like the .25. I just do.

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    3. I have not touched the 25 since I finished this test. I did pick up some additional boxes of 25 when I saw them available, but I'm still waiting to find a box of the Winchester Super-X Expanding Point.

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  3. Maybe we can see some of the more modern loads tested in the future such as the 35 grain hollow points and maybe the Win 45 grain pellet nose?

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  4. Thanks for the ord gel test. Penetration tests using 2X4s and phone directories are useful only to those who expect to be attacked by odd scraps of lumber and paperback books.

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