You are looking for Mk 262 mod 0 or Mk 262 Mod 1. Bullet is a 77 gr. SMK, IIRC.

http://www.black-hills.com/whois.htm (Read the comments.)

http://en.wikipedia.org/wiki/Mk_262

SSA also has a 77 gr. Sierra OTM loading.

 

The MK262 isn't all copper like the OP's link states the "optimized" ammo to be.

I have no personal experience with "brown tip" 5.56, but I have used the Black Hills 77gr ammo quite extensively. When I shot it, it wasn't labeled MK262, it was labeled "77gr Moly, Loaded for USMC Shooting Team", but I think it was the same thing.

From the description the OP gave, it sounds like something else.

 

The MK262 isn't all copper like the OP's link states the "optimized" ammo to be.

I have no personal experience with "brown tip" 5.56, but I have used the Black Hills 77gr ammo quite extensively. When I shot it, it wasn't labeled MK262, it was labeled "77gr Moly, Loaded for USMC Shooting Team", but I think it was the same thing.

From the description the OP gave, it sounds like something else.

I believe this is the .223 "match" load and not the 556 level load. The 556 load is just a tad hotter.

 

Yes, the brown tip is a monolithic solid similar to the Barnes. The info I could find also did not give an official military nomenclature but said that it was a 70 gr projectile.

 

SSA makes a 70 grain TSX in a 556 preassure load...........

 

Stan here is a thread from arfcom http://www.ar15.com/forums/topic.html?b=3&f=16&t=378548

 

Thanks. There were a few useful nuggets in with all of the misinformation and emotional posts.

"While the U.S. does voluntarily try to stay within the standards of the Hague Peace Convention, they are not bound by it nor do they fully comply with it. If the U.S. decided to adopt a high expansion round, they are perfectly free to do so with the only repercussions being possible political fallout from other nations."
~ Doc40nTX

I have it on good authority that there is currently no Mk- or M-number for the "brown tip" ammo, though.

 

maybe not but SSA does provide some .mil ammo and they have the 70 grain TSX on thier website.... you can draw your own conclusions....

 

Brown Tip 5.56mm for Short Barrels
by James Dunnigan
June 5, 2008

Discussion Board on this DLS topic
U.S. SOCOM (Special Operations Command) has used its own, bureaucracy free, budget to design and manufacture special ammunition for the short barrel (10-15 inch) weapons (like the M-4 and SCAR Light). The new ammo, referred to as "5.56 Optimized", or "brown tip" (because the tips of the bullets are brown for easy identification) uses a bullet that is solid copper and 70 grains in weight (compared to 62 grains for the NATO standard 5.56 bullet). The solid copper design is believed to be based on a commercial design (the Barnes Triple-Shock X) that was introduced five years ago. The new round was designed to achieve better accuracy and hitting power at the ranges (under 300 meters) the short barrel weapons are most effective at. The brown tip ammo costs more, because of its unique design and small production runs, but SOCOM doesn't worry about that when it's for something that will make its operators more effective, and help keep them alive.

The above came from the strategypage.com:

http://www.strategypage.com/dls/articles/200865222012.asp

Another dot connected?

I could not find a designation either. Darn Google.

 

Now, just imagine if the Brown Tip were a 6.8 SPC 85 grain bullet traveling at 3000 FPS from a 14.5" M4? Or, perhaps 2850 from a 10.5" CQB carbine?

That same 70 grainer will only be going 2650 from the 14.5, and 2450 from the 10.5. Fifteen grains more bullet, 400 FPS and all that much more energy.

Dead taliban, with one round, everywhere, even if from behind mud walls. It just makes so much sense.

I know you didn't ask for a comparison, Stan so I apologize for the hijack.....
Now back to our regularly scheduled program....

 

Hmmmmm, lets do the math on that.

70 grain TSX at 2650 fps = 1091 FPE
70 grain TSX at 2450 fps = 933 FPE

85 grain TSX at 3000 fps = 1698 FPE
85 grain TSX at 2850 fps = 1533 FPE

I know which one I will take.

 

Now if they would only make that 85gr a blue tip!

 

Here are some other related links.
It may be that all 3 apparent versions are in testing...

New non-6.8 mm military ammo developments: http://www.m4carbine.net/showthread.php?p=384549#post384549

Help me out here.

Is the LFS different than the MK 318/MK 319 enhanced?

I don't have real high hopes for the LFS if its just a FMJ construction with different filler.
The hard target test results are interesting though
with the 556 LFS penetrating 3/8" steel at 300+ meters and masonry at 150 meters
vs the M855 penetrating 3/8" steel up to 150 meters and being STOPPED by the masonry.

The construction of those Mk318/319 looks like the rear half is just like Barnes TSX and the front an OTM.
The velocities they are getting are excellent.
556 62 grain @ 2925 fps from a 14" barrel.
762 130 grain @ 2925 fps from a 16" barrel.

These options appear to be approaching cutting edge performance led by the 6.8
This is good and bad.

 

I just wonder how the TSX performs on Humans. Does it go right through like on deer, or are humans tough enough that the TSX will actually expand?

 

Does it go right through like on deer

I thought we were still waiting on the answer to this?
Did someone get a shot at a deer with a TSX round with bad results and I missed it?

 

http://www.ar15.com/forums/topic.html?b=3&f=16&t=378548&page=13

Poster Whelen wrote:

"I killed a 180 lb buck last November with a Barns TSX handload. Distance was about 75 yards, and I was using a 14.5", 1:7 barrel, shooting from ground level. Bullet hit left shoulder, angling back to go through lung and stopped somewhere in body cavity. It did not go through far side ribs. While I spend some time looking for bullet in and around lungs, I found it by chance while removing inner loins. It might have bounced off far side ribs and headed to the stern before stopping. The bullet mushroomed perfectly. Deer was temporarily immobilized, but not dead, and after a few minutes, hopped up and limped 100'ish yards before expiring.

In my experience with the Barns bullets, and mostly with the previous generation XBT in 30 caliber, the Barnes bullets always expand, and always in the same manner, and with a 30 caliber bullet, deer are so impressed with the bullet, that they fall where standing, or very close by. For a 22 caliber bullet, these TSX bullets seem to work well, and don't loose any weight on expansion. That said, if you want fast results without resorting to an iffy headshot, then a bigger bullet is better.

In the end, the critical factor is going to be shot placement. While these TSX's are good, in the 224 caliber version, I don't think they are some black magic touch of death.

Whelen"

 

Thanks for the info DocGKR, yea I was pretty sure the TSX's would expand beautifully on shoulder hits. I'm just waiting for someone to post results from a ribs/boiler room hit or better yet slipping one in between the ribs.

Maybe that someone will turn out to be me this fall.

 

This is what I don't get. Why the 70 GR TSX? The Military uses the 62 GR M855 and it is being replaced by the new 62 GR whatever it is called. Why not go with the 62 GR TSX bullets? It would have the similar BC as the M855 replacement and nearly the same velocity, which means same trajectory and can use the same ACOGs. For a 70 GR Bullet, the BC of .314 is not all that impressive.

 

Plus the 62 grain TSX can be driven faster for better expansion at longer ranges. It's funny, I can drive an 85 grain TSX faster in my 8" PSD than the 70 grain TSX out of a 14.5" M4.

 

I've chrono'd the 70's with my handloads out of a 16" barrel. They are faster than I remembered:

1. 70 gr TSX, 24.3 gr H4895, LC brass, CCI41
16" barrel - 2783 fps 10.3" barrel - 2499 fps

2. 62 gr TSX, 25.5 gr H4895, LC brass, CCI41
16" barrel - 2924 fps 10.3" barrel - 2560 fps

3. 62 gr TSX, 23.5 gr H322, LC brass CCI41
16" barrel - 2862 fps 10.3" barrel - 2646 fps

The 10.3" upper is an older LWRC and has always chronographed high. It shoots M193 LC at 2800 fps.

 

24 grains of H322 is geting me 3000 fps from 16 barrel, for 62 gr TSX. And 2800 from 11.5 inch gun.