A Visual Comparison of the Precision of Various 5.56mm Loads

[Molon]

A Visual Comparison of the Precision of Various 5.56mm Loads


The graphic below shows the results of three 10-shot groups of each of the various 5.56mm loads, fired in a row from semi-automatic AR-15s a distance of 100 yards, over-layed to form 30-shot composite groups.




https://app.box.com/shared/static/uxo5vbf4xz5sj08icjx1zkmpnok2zmwn.jpg





1. Prvi Partizan M193

2. PMC 5.56 NATO 62 grain X-TAC

3. Hornady 5.56mm 55 grain GMX TAP Barrier

4. Hornady 5.56mm 75 grain Superformance

5. Black Hills 5.56mm 77 grain Tipped MatchKing

6. Barnes Precision 5.56mm 85 grain OTM





https://app.box.com/shared/static/h9tlbyrazuu4v0gjb9720lcdhn1g3i4q.gif



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[Jerry R]

Very interesting. Any cleaning regimen between groups? Barrel length and twist rate? Firing sequence match the listing sequence?

[gatordev]

Interesting to see the Prvi. I've put a lot of Prvi M193 through several of my rifles, and some like it better than others, but it looks like your results match (and maybe even exceed) my experiences with it. Great for blasting 100y and in, but really starts to fall apart beyond that.

[DUX]

Hello. I registered to ask a question about this post in particular. I shoot M193 non-boat tail exclusively. However, I am concerned that my barrel twist is over stabilizing my rounds. (It's a Voodoo Innovations 18 inch, pencil barrel with a 1:8 twist) I'm interested in getting the majority of my rounds to be highly unstable and "keyhole" as much as possible in the 100 to 150 meter range. (I understand most people don't think this is a good thing, but I think that as a matter of energy transfer for a defensive weapon it is a good thing so I want to pursue it) Since my goal is a a high speed, un-stable round with reasonable accuracy (3 MOA@ 100 meters is fine by my personal standards) what bullet weight would be ideal to achieve this effect for the barrel that I currently have?

My original goal was to have a rifle that slings a 55grn. projectile that would not exit a human body in a firefight, but would dump roughly 3000 feet per second of velocity into the body, disintegrate, and cause massive internal cavitation; essentially turn the targets insides into jelly with reasonable accuracy at the most common real world engagement ranges for an AR platform. I do not think I've achieved that yet. Many thanks in advance for any advice.

P.S. I tried to source a 1:12 or even a 1:14 barrel when building this rifle but could not find one at that time in a light weigh profile. I'm trying to work with what I've got. (concept idea developed after discussions with Vietnam era medics)

[DUX]

Hoping to give this a little bump. Perhaps I should make a new thread but hopefully some of you guys share interest in rounds that DO NOT exit the body. (I.e. 6 inches at MOST of penetration and tumbling and fragmenting all to hell and back. A real organ scrambler of a round) I was hoping to find a combination that would let an off the shelf bullet achieve that at pragmatic ranges but if anyone can think of another round/rifle please, throw the idea out there. Thanks all.

[Joelski]

Try filing a flat spot onto one side of the projectile to get a tumbling effect. It will affect accuracy and increase lead fouling, but you should get close to what you're wanting to do.

[DUX]

Thank you for the reply. I wonder if you could just cut a notch on the forward tip and make it extra unstable? I'll have to give it a try next time I go shooting. If I can get them to start key-holing every time inside a man sized target at 100 meters, then I can make some gel and see if they're not over penetrating. The whole idea is to make the rounds as pig-nasty as possible and avoid "ice pick" wounding. I shoot on my private land so I can experiment. Thanks again.

[Joelski]

I saw that study on asymetric projectiles. Devastating. Kinda makes you wish the whole world followed the Geneva Convention's Articles of War, however the bad guys use hollow points and shoot at medical insignia, so at least Hollow points are being adopted.

[DUX]

I know of a guy shot 9 times with 7.62x39 steel core rounds. He's doing fine! I saw some photos of 55grn. tumblers once. I don't think that fellow is fine. :)