Ballistic gelatin test results : US M193 versus bare gelatin


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Brass Fetcher
September 4, 2009, 07:06 PM
3 55gr FMJ-BT shots were fired from a Bushmaster AR-15 with 16" barrel and 1/9" twist at 3 bare gelatin blocks.

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Dr.Rob
September 4, 2009, 07:26 PM
Solid work, suprised you got such a variation in velocity. Same ammo lot?

Also, I'd be curious as to the weight of the recovered projectiles, esp the one that 'kept on going'.

Maverick223
September 4, 2009, 07:37 PM
Interesting test...I find it unusual that they tend to fracture at the cannelure...I am more familiar with rounds that ran out of toothpaste like the final one (lead squished out)...though I am not terribly surprised because they are 5.56. Thank you for publishing the findings. :)

DMK
September 4, 2009, 07:41 PM
Thank you JE223!

Looks like it would do a pretty nasty job on the poodles heh?

Any chance of a 75gr OTM/HPBT test at some point in the future?

iamkris
September 4, 2009, 09:29 PM
I'd second DMK's request. Also, I'd like to see both bullets run at decreasing velocities...maybe 200 fps increments...down past the point of fragmentation. While these pix are neat, they are at almost muzzle velocity speeds. If I'm shooting someone / something right at my muzzle, I'm having a very bad day.

Maverick223
September 4, 2009, 09:34 PM
If I'm shooting someone / something right at my muzzle, I'm having a very bad day.Not as bad as "someone / something". ;) I second the test with different projectile weights (62gr. in particular) and would very much like to see velocity loss (to simulate distance). :)

Maverick223
September 4, 2009, 09:36 PM
If you are in NC and don't reload I would be more than happy to load some up for a test...so long as I get to see a test. :)

dispatch55126
September 4, 2009, 10:08 PM
My Del-Ton w/ a 1 in 9 16" prefers 62gr over 55gr though Prvi M193 runs fine. I'd like to see what my 62 gr. does. How hard is it to make the ballistic gel?

Z-Michigan
September 4, 2009, 10:59 PM
Thanks for posting!

Results look exactly like Fackler and all other M193 gel tests I've seen.

I am curious about the first shot with 3230fps out of a 16" barrel. That round must have been loaded hot!

Maverick223
September 4, 2009, 11:02 PM
How hard is it to make the ballistic gel?How hard is it to make Jello? Never made it...but I have heard it is that easy...just stick to the recipe, proper temp, and humidity. Though it is pretty expensive IIRC. :)

gga357
September 4, 2009, 11:15 PM
I have read that temp is a big deal with ballistic gel. I don't know that it is.

Brass Fetcher
September 5, 2009, 02:24 PM
The ammo was from the same lot ... Lot V 49 W752 from Federal. Unless asked to do otherwise, I typically select 3 cartridges (pseudo randomly) from a box from the same lot for each test sequence.

Here are the weights of the recovered fragments :

Shot 1 nose section - 33.6gr
Shot 1 base section - 12.5gr
Shot 1 recoverable fragments from lead core - 6.2gr


Shot 2 nose section - UNK. I looked through the lab again today, and was unable to find this fragment. Since the velocity/stagnation pressure acting on the projectile was lower than Shot 1 and the fragments recovered were larger, I would assume that the nose section weighed at least 33.6gr.

Shot 2 base section - 17.1gr
Shot 2 recoverable fragments from lead core - 3.9gr


Shot 3 nose section - 45.5gr
Shot 3 recoverable fragments from lead core - 3.9gr

The velocity variation was a bit of a surprise to me, too. Perhaps this was due to the shorter-than-20" barrel length spitting out partially-deflagrated propellant that would have otherwise burned in the longer barrel.

Brass Fetcher
September 5, 2009, 02:29 PM
@DMK - Testing the 75gr round really wouldn't be any different than any other 5.56mm round ... but it's not currently on the schedule.

@iamkris - This test was intentionally set up as a 'worst case' scenario - close combat at room distance.

But this test was just a start ... seeing all of the positive responses to this test has put the fire under me on this round ... expect to see more involved M193 tests in the near future.

John

taliv
September 5, 2009, 05:07 PM
suprised you got such a variation in velocity.

keep in mind it's XM193 not M193

no telling why it got rejected

rbernie
September 5, 2009, 08:14 PM
JE223 - if you need any 75gr OTM loads, I have a bunch that I made a while back that I'd gladly donate to the cause.

Brass Fetcher
September 5, 2009, 09:42 PM
Thanks for that rbernie ... I will let you know if that test shows up on 'the list'...

Dr.Rob
September 5, 2009, 10:57 PM
Thanks JE223, 'retained weight' of the projectile is something I'm curious about when they show hunting and hollowpoint rounds. That second shot is more how I expected all the tests to look.

LaEscopeta
September 6, 2009, 12:13 PM
Glad to see the test repeated 3 time; much more useful that the one shot tests you usually see.

Does anyone shoot these gelatin blocks at ranges of 50 to 200 meters? The range these rifles are likely to be used at? Just asking…

Maverick223
September 6, 2009, 02:00 PM
Does anyone shoot these gelatin blocks at ranges of 50 to 200 meters?I doubt it (nor have I read any that were), most will just simulate the loss of velocity with lesser loadings...something that I'd love to see...hint, hint. :)

counterclockwise
September 6, 2009, 02:14 PM
.
The photo's say M193, but someone said XM193. Which is it?

The text said shot 3 continued to fragment at the cannelure, but the photo of fragments shows the cannelure intact. Which is it?

The 3000 FPS slow one, I suppose, was serendipity. That would be terminal velocity at CQB ranges for M193, would it not?

Anyway, great data. Thanks for all the work and showing it here.

Brass Fetcher
September 6, 2009, 07:13 PM
Corrected. Thank you for the heads-up.

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