I was looking through posts on failures of m855, m193, and mk262 to yaw/fragment, and I came on two studies that determined what they think the problem is.
1. All bullets violently yaw around their line of travel for some time out of the muzzle until they stabalize (http://www.dtic.mil/dtic/tr/fulltext/u2/a519801.pdf)
2. This accounts for random terminal performance in soft tissue, since a bullet hitting at a high angle would yaw dig a wide channel and others would ice pick. (https://docs.google.com/viewer?url=http://www.dtic.mil/dtic/tr/fulltext/u2/a458409.pdf)
The solution was to create ammo that would wound independent of yawing, i.e. m855a1 and mk318. My problem is that I cannot determine what this wounding mechanism is, exactly.
Best I can determine from gel tests and pictures online is that the copper jackets are very thin and the mounts of the jacket are (especially in the case of m855a1) very wide, compared to normal OTM or FMJ bullets. This appears to always result in lots of fragments of copper coming off the bullet as it enters tissue.
Two questions: Is fragmentation not what they meant by yaw independent wounding? And is this basically the US throwing a big middle finger to Customary International Law on expanding ammo? Fielding a round with a jacket designed to become shrapnel upon impact seems to piss all over that law.
Bump because you seem to have out some effort into this
I should add, this is for wounding deficiency within cqb distances. m855 ice picking at 250m is a different ball game.
Also a stupid typo where I typed case mount instead of case mouth.
>>34150207
pretty much the further development of fragmenting rounds was to ensure quick kills with minimum munitions from a single soldier and since expanding rounds did that well they said no no to using them hence the birth of modern multiple wound vector munitions in form of high speed copper shrapnel
What's the best all around 5.56 round that's available on the US civilian market?
>>34150778
mid 60 grain bonded core if your worried about barrier blind, mid 70 grain tipped match ammo if your not
>>34150794
I need brands n shieet.
>>34150804
Federal 62gr TBBC
BH 77gr TMK
>>34150207
They are creating rounds that more reliably fragment at lower velocities.
That's the basic explanation, fragmtation is the wounding mechanism, and no this does not violate international laws on expanding ammunition because these rounds aren't designed to expand, only to fragment.
>>34150491
Well long range performance has a lot to do with this, Mk318, Mk262 Mod1 and M855A1 all fragment at lower required velocities more consistently than M193 and M855, thus extending the range that the round isn't going to "Ice Pick".
>>34150778
I use 77G OTM as my go to SHTF load
>>34150832
>using yesterdays bullets
>>34150832
The US never signed on to the part of the treaty that bans expanding ammo. We can use use whatever the fuck we want.
>>34150857
They're still amazing and when I surprise my AR I worry about baffle strikes with poly tip ammo, happened to a tripfag on here before.
>>34150861
Then show me what expanding rounds the US military uses
I want a battle rifle in x54R that doesn't cost a fucking gorillion dollars. Is a Vepr my only option?
>>34150207
Dude get 5.45 lmao
>>34150888
The problem is that the SMKs tip is too narrow, delays fragmentation and yaw. The older SMKs were wider, and moar gooder. Not sure about baffle strikes. Id ask your can mfg about issues.
>>34150888
>Then show me what expanding rounds the US military uses
I never said expanding ammo was standard issue.
>>34150892
Just get .308, its basically the same thing, ballistically speaking.
>>34150861
International Customary Law or however you say it is not the Hague Convention. We informally follow it with the assumption other countries do the same. Ditching it has consequences we may or may not want.
>>34150207
You might as well as include the basic rule of "it wasn't fast enough". These rounds will frag like shit out of shorter barrels at range, and the army doesn't want to lose the advantages weight reduction and mobility.
>And is this basically the US throwing a big middle finger to Customary International Law on expanding ammo?
Technically no, since it fragments and doesn't "expand". Look, it's a technicalities in war. Technically they could've been terrorists. Technically that was a combat zone. Technically I didn't know those were reporters.
But also the US wouldn't care, since whoever is up in Genevia is full of themselves thinking banning expanding ammo is humane (if anything it's less).
>>34151279
Hague*
>>34151316
I meant as in Geneva, Switzerland. Not the convention.
>>34150832
>Well long range performance has a lot to do with this, Mk318, Mk262 Mod1 and M855A1 all fragment at lower required velocities more consistently than M193 and M855
My understanding is that M855A1 and M318 rarely fail to fragment even at lower velocities (no idea where the cutoff is, but M318 had short barrels in mind). In both cases, the internal components force the case mouths open wide at impact, nearly always causing the jacket to come apart.
This was how we sidestepped this issue with Mk262. It wasn't designed to fragment 100% of the time, it's a side effect of the way we swage the bullet, and it does occasionally fail to deform even at higher velocities. That does not appear to be the case with both newer ammo types.
>>34150888
It happened to Giddy because he's am idiot.
>>34152425
But how? How did a plastic tip end up fucking up his suppressor?
>>34150888
dan, it happened to me because i got my can and barrel hot as fuck, tip melted and that destabilized it.
just don't do magdump after magdump with poly tip and it'll be fine.
While I haven't seen m855a1 anywhere (and I probably wouldn't want to use it without the feed ramp upgrades), apparently mk318 is commercially available now.
>>34153309
And the gel test. Roberts reported a 62gr bullet going +2900fps out of a 16" barrel. No idea how, since usually max reloading data usually tops out at 3000fps out of a 24". Maybe mk318 is over SAAMI spec as well.
>>34150778
>>34150804
64 grain speer gold dot is my go-to ammo