Mk262 vs Mk318.....which is more lethal?

[sinister]

Mark 318 is loaded with a General Dynamics - St. Marks military powder which is commercially labeled as CFE (Copper Fouling Eraser).

How dead does your target have to be? Dead is dead -- hit him in the CNS with M193, 855, 855A1, 318, 262, or 294 and he's just rotting protoplasm.

[markm]

Mark, what powder/primer combination do you use

I use WOLF SRMs with XBR 8208. Guys who run ball powder like TAC can get higher velocities than I can with XBR. There's a Mk262 clone thread in the reloading forum.

[ST911]

Unless you can meet all the production and testing specs, you're not cloning. You're mimicking. It's the difference between being the guy that builds a box, and the mime that has to guess at it's boundaries.

Good thread from 2015: "If you had to choose between Mk262 and Mk318......"
https://www.m4carbine.net/showthread...k262-and-Mk318

As others posted, 318 and 262 are different loads with different parameters and purposes.

[rickgman]

Will M855 and Mk318 generally shoot to the same POA? They're both 62gr, but of course the BC is probably different.

I understood that Mk318 ammo was suppose to perform similarly in terms of external ballistics to M855 ammo but my experience seems to indicate that this is not exactly true. They seem to have very similar vertical points of impact but Mk 318 ammo seems to consistently shoot to the left by about 1 to 2 MOA when compared to M855 ammo. Has any one else noted this phenomenon?

[C-grunt]

I'm a fan of M262 as I used it in my second tour in my DMR. My buddy also used it later on in his Mk18 out to distance with good results.

Is it better than Mk318? I have no idea and from what some very knowledgeable people say, maybe not. But it has proven itself to me.

I think people get a bit too wrapped up in rifle ammo. I know we are all gun guys and that's what we do, but I've seen plain jane M855 put a lot of dudes in the dirt. And that's supposed to be one of the worst projectiles for reliable lethality. That doesn't mean I don't think it had issues and shouldn't have been replaced though. As a cop I've seen several dudes smoked with cheap 55 grain steel cased ammo. It's works.

I've always had the plan that I keep a few (3 or 4) mags loaded with good defensive ammo. Everything after that is M193.

[rickgman]

I think people get a bit too wrapped up in rifle ammo. I know we are all gun guys and that's what we do, but I've seen plain jane M855 put a lot of dudes in the dirt. And that's supposed to be one of the worst projectiles for reliable lethality. That doesn't mean I don't think it had issues and shouldn't have been replaced though.

I certainly agree that folks can get too wrapped up in attempting to determine which is the "best" ammo. In some cases, I believe that the differences between two types of good ammo (like Mk 262 and Mk 318) is so small that it is insignificant. However, one of the major issues I see with M855 ammo is its high sensitivity to yaw angle. In the real world, it can be very effective or it can be quite ineffective in terms of terminal ballistics - much of this is due to its high sensitivity to yaw angle. That's something that simply can not be controlled by the shooter. Much has been made of the lack of accuracy of M855 ammo but to be honest, I don't think it is all that bad unless one is making shots beyond 300m.

[sinister]

My guess is the majority of drive-by readers on this board don't shoot to 300.

Bullet question threads like this almost always trigger an Immediate Argument Drill.

[rickgman]

My guess is the majority of drive-by readers on this board down't shoot to 300.

Bullet question threads like this almost always trigger an Immediate Argument Drill.

You are probably correct. Even at 300m, the extreme spread of a 10 shot group shot using M855 ammo and an M16A2 rifle are well within an E type target - assuming the rifle is properly zeroed, of course. At 400m using the same ammo and rifle, the extreme spread just barely falls outside an E type target in the horizontal direction. That's plenty good enough for most folks in real world scenarios. If one is shooting service rifle competition, it isn't nearly good enough but that's another matter.

[XD40Colorado]

Mk 318 has better terminal ballistics due to its shorter neck length before fragmentation. As far as effectiveness out to 300m, mk318 will upset down to 1900-2000 fps vs mk262 which needs ~2300 fps to fragment so it would depend on your barrel length.

The reason barnes TSX copper fouls excessively is because its a pure copper bullet. Mk318 I believe uses a gilding metal jacket so it shouldnt copper foul as much.

Also consider accuracy. MK318 is 2 MOA (2" at 100 yds, 4" at 200 yds, etc), whereas MK262 is 1- or sub-MOA accuracy.

[pointblank4445]

Also consider accuracy. MK318 is 2 MOA (2" at 100 yds, 4" at 200 yds, etc), whereas MK262 is 1- or sub-MOA accuracy.

The T556TNB1 Federal that was available and supposedly commercial Mk318 (but is likely just "factory seconds") is pretty unimpressive accuracy in the guns I've seen. I'd rather connect with mediocre projectile than miss with an "optimized" projectile. If barriers were a concern, I'd lean toward a Barnes solid TSX like Brown Tip.