5.56: Fragmentation or Expansion?

I don’t plan to engage 2 legged critters at ranges in excess of 200 yards, so minimum velocity for expansion isn’t something that concerns me personally. I’d rather be confident that the bullet will stay together at close range and through thin barriers, than that it’ll expand in a situation that will likely never occur. I’ve got better performing rifles than the 5.56 AR for instances where long range defense may be required…time to go fondle a 19.25" M21DMR.

I load 62 grain Barnes TAC-Xs that have in excess of 2200 fps at 200 yards. My research indicates that these bullets need 1900 fps to expand.

62 gr fusion - 1350
https://www.m4carbine.net/showthread.php?65698-Federal-Fusion-223-Expansion-threshold

I’m definitely behind the curve, but I think I read that M855A1 is quite a bit higher in pressure than other 5.56 rounds. Is that correct? And is it only available to the military?

Our sources indicate the pressure has been reduced to normal 5.56 levels.

It’s not available to civilians, it’s replaced M855 in the Army and more recently Marines. It is slightly higher pressure, but the fears of causing extreme excess wear seem to be overblown and I can’t tell any difference recoil wise. Here’s some videos on it:

https://www.youtube.com/watch?v=d8IvDPuVuho&t=

https://www.youtube.com/watch?v=PeNR4YDbwR0

https://www.youtube.com/watch?v=QItA83cPpS4

Thanks for the info.

So I’m guessing the projectile does not have a commercial equivalent? Who makes it?

*I will check out the videos, thanks!

Apparently you can buy the projectile and handload rounds. The majority of youtube vids on it are handloaded and not actual mil factory loads.

OT, but here’s the M80A1 round (7.62) we use in our M240L’s

https://www.youtube.com/watch?v=2PmUikWEGgw

Theoretically fragmentation has the potential to cause more damage since you are increasing the chances of puncturing something important off the main wound track. You generally see larger permanent wound cavities in gel as well with fragmenting rounds.

But realistically either type of round seems to drop dudes equally well. Bonded soft points are generally more consistent, followed by copper solids then OTM and FMJ.

The exception is M855A1 which you can’t easily get and 77gr TMK which is a non yaw dependent OTM. Probably the 2 best choices for fragmenting rounds.

Why do you say that bonded soft points are better than copper solids? I’ve only heard good things about the TSX

Low expansion threshold, inexpensive, good BC, good starting velocity with equivalent pressures. Gives up nothing on barriers, maybe better.

TSX’s are no slouch, by any means.

Copper solids are very good, they just don’t do as well through tough barriers, anything that will damage, plug or collapse the tip will cause it to not expand so they aren’t as consistent through barriers like SPs.

Do they have any benefits over SPs?

More than likely have a better ballistic coefficient.

Really, just pick a round you like and stick with it. I do believe the bonded soft points are better because of the more consistent performance through barriers. That being said, fragmenting rounds can still be very effective through barriers. We use Federal TRU 223E which is a 55 grain hollowpoint. I’ve got several buddies at work who have shot successfully through windshields, car doors, and windows. I’ve personally seen it go through a forearm and still be effective.

Like I said, I do believe the bonded soft points are better. However I’m not worried about my duty ammo be ineffective.

Better BC, deeper penetration, no meat contamination for those who hunt.

I think people really overthink the 5.56 round when it cones to personal defense. Just pick a round, and place those rounds where they need to go when/if the need arises. It is a rifle round after all.

DocGKR would tend to disagree with you, I’d assume.

Neither is going to make a dramatic difference when placed where they belong, neither is going to make a dramatic difference when their not. Intermediate barriers aside, it’s really splitting hairs. However, since we live in an imperfect world and intermediate barriers are a thing, I think now that we have an abundance of quality SP and solid expanding ammunition, that is the best overall option.

Fragmenting ammunition may cause more tissue damage, but that’s not going to have any marked difference in the immediate outcome than a JSP or other similar round.

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How so? Are you saying shot placement isn’t important? Because that’s what I was getting at. I do think people nick pick over shit when just about any 5.56 round will f**k someone up far more then any handgun round.