Interesting article about .223/5.56 caliber in military use

[v-rog]

Both my wife's carbine and mine have 1:9 barrels. I've got about 440 rounds on hand of M855, about another 400 rounds of M193, and then maybe 150-200 rounds of assorted other ammo like 68 and 69 grain match and 55 grain soft points on hand. So far, I can't tell any significant difference in accuracy between the M193 and the M855, and both zero to the same point at 50 yards. The only notable difference seems to be the cost, and that's not a large difference. I don't really need a penetrator round........I don't think. I only bought the M855 because I wanted to try it out. My son and I bought and split 1,000 rounds of it.


Chris, I'd think you would have to shoot the rounds further than 50 yds to see substantial differences.


If I had a rifle that cannot stabilize the heavier round I would be replacing the barrel with a 1:7 but that is just me.[/quote]
As to swapping out the barrel for a 1:8 or 1:7, I've thought about it, but the 55 and 62 grain bullets both perform well in 1:9 barrels, so I don't really see the need to do so. Also, that's money that could go toward a 6.5 or 6.8mm upper.....

I was curious so Last week I shot a box of Fed Gold Match Sierra 69gr HPBT rounds through my RRA LAR15 (1x9, 16") at the 100yd rifle range (Elm Fork). The 1x9 twist stabilized the rounds, I didn't get any key-holing, and the average velocity was 2550 fps. Granted, it was only 20 rounds but I'm doing more testing, and I plan on shooting at further distances with the heavier bullets.

[mdoan300]

The .223/5.56 FMJ wounding mechanism is through tumbling and fragmentation. The fragmentation threshold is 2600fps. Anything less than that and you'll get inconsistent results. Google "m855 fleet yaw"

You guys should check out the ballistics forum on m4carbine.net. DocGKR has done all the ballistics testing and research for us and he has listed his picks for suitable .223/5.56 loads.

Mk318 SOST has been available to consumers for a while now. CTD sells 2-3 varieties of it -- 2 Federal flavors (white and brown box) and a BVAC flavor (white box, I think) for around $15k/box-20. While DocGKR indicate that the Mk318 is an ok load, there are better ones out there for HD/SD/barrier penetration/etc.

[JeepGuy79]

I don't have any of the m855a1 but I have a few boxes of mk262 mod1 in the safe. I have not shot any yet. I want to shoot it some distance and see how it does and there are no ranges with any real distance close to me that I know of. I have a 10.5" 1:7 upper I want to see how it does it distance. Sorry, not trying to throw this thread off further than it already is.


Hey TAM, did you find m855 for the same price as m193? If so where at if you don't mind me asking?

[Terlingueno]

2004 is outdated info. The Marines are now using a 77 grain open tipped round and the Army is keeping their penetrator round with some tweaks. the new Army round has a steel tip, lead middle so it can still mushroom. followed by a solid copper tail. The M855 didn't work because it just went through people, it didn't mushroom.

No, the USMC is using the 62 grain MK318 Mod 0 SOST round in Afghanistan. I bought a few boxes from Ammunition to Go and it's a little more accurate than M855. The SOST round is a barrier blind bullet in which the forward portion fragments and the solid copper tail remains intact.

[remington79]

Oh thanks. I thought it was in the 70 grains. I've seen so many different articles on 5.56 rounds that it's hard to keep them straight. Especially when you can't find the links to them again to refer back to.

[TEX]

The 5.56 can be an adaquate round and I have a cabine chambered in it - I carry only Corbon solid copper DPX HPs in it and for a good reason. I too started on an M-14 way back when and wasn't too please with the swap to the M-16. It look ed really cool, was light and you could carry a lot of ammo, but that extra ammo was often not used to good effect. The 5.56 can do well if you catch the goblins in the open and they are not high - 7.62 might work better and 308 certainly would, but as many have said, you trade firepower for round count.

The issue with me has always been what I might have to shoot through to get to the Goblins, and in that area I don't think the 5.56 does as well as the 7.62 and certainly doesn't do as well as the 308. In the military version of the 5.56, I think they took two steps backwards from the original M-16. First they went to the heavier SS109 to get pentration and then they went to the shorter barreled M-4, so what was once a screaming 55gr bullet moving out at almost 3300 fps, you now have a 62gr bullet moving at perhaps 2800 fps (and even less at distance) - don't know the exact numbers as I have never had an opportunity to chrono this - so its a WAG, but I bet I am pretty close. If you have read Black Hawk Down, it seemed to me they were not very happy with the effectivness (or delayed effectivness) of the 5.56. I use the Corbon DPX rounds in my 5.56 carbine, because they are still moving fast out of my 16-inch barrel (3,000 fps+) and give better penetration and performance than the standard FMJ - with a plus that they group wicked tight for some reason out of my rifle. From a civilian standpoint, what I have works for me as I probably will never have to engage anything beyond 100 meters or shoot through anything purposly designed to slow down or stop small arms fire. I have tried this DPX and it goes through regual car doors windscreens and wall pretty well. I have something heavier if need be. In a militray role (for me personally), I would feel the 5.56 was marginal. If I had my way, I would issue a American modified version of the AK (additonal features) with the 7.62 case necked down to 7mm with about a 100gr projectile - I should think you could get it up to 3,000 fps and it should be pretty flatshooting and effective out to 300+. If I just had to pick something up, I would go with an FN-FAL (carbin version with folding stock).

BTW - I am not trying to flame anyone here, but there was a comment about "Well they sure wouldn't volunteer to get shot by such-n-such caliber". I here this all the time and considered it to be one of the most goofy statements made by folks in our hobby group. Find me anyone sane who would volunteer to be shot by a .22 short (you won't) and then the statement might mean something.

Soap Box Mode Off


TEX

[The Annoyed Man]

I was curious so Last week I shot a box of Fed Gold Match Sierra 69gr HPBT rounds through my RRA LAR15 (1x9, 16") at the 100yd rifle range (Elm Fork). The 1x9 twist stabilized the rounds, I didn't get any key-holing, and the average velocity was 2550 fps. Granted, it was only 20 rounds but I'm doing more testing, and I plan on shooting at further distances with the heavier bullets.

Roger, I've shot the 68-69 grain match through my old varmint rifle with a 1:9 twist at Elm Fork on the 100 yard line, hundreds of rounds worth over the years, and it performed just fine and stabilized the rounds. Unfortunately as you know, Elm Fork won't allow the FMJ stuff on the 100 yard line. But it seems to me that if group sizes and POI are roughly the same for both M193 and M855 at 50 yards, they will likely have similar performance at 100 yards allowing for increased group size over distance.

Anybody got a few hundred acres they'd be willing to let me set up some targets on so that v-rog and I can go out there and kill the bad paper?