Identify this 5.56 ammo...

[16Bore]

Looks like steel, but I thought all that shit was green.

View attachment 181962

 

[EastMT]

Army begins shipping improved 5.56mm cartridge

 

[Formidilosus]

As above, M855A1. It is not commercially available. Everything on the market is ammo that was taken home by someone.

It is a three part projectile- copper jacket, solid copper plug, and steel arrowhead tip. It does greatly improve terminal performance, however at the cost of barrel/bolt wear, and does NOT improve precision over M855 “Greentip”.

 

[Ripnbst]

As above, M855A1. It is not commercially available. Everything on the market is ammo that was taken home by someone.

It is a three part projectile- copper jacket, solid copper plug, and steel arrowhead tip. It does greatly improve terminal performance, however at the cost of barrel/bolt wear, and does NOT improve precision over M855 “Greentip”.

How do you figure its going to wear more on the bolt / barrel?

 

[Formidilosus]

How do you figure its going to wear more on the bolt / barrel?

I’m not figuring. I have personally fired more than 100,000 rounds of A1 in the last three years. I have seen, many, many times that fired in near closed environments where reliability and precision are watched carefully.

Barrel and bolt life is approximately half of M855 “green tip”. Early lots of A1 were both higher pressured, and the powder used maintained that peak pressure longer. This resulted in rapidly broken bolts and enlarged gas ports- we had a number that had bolt lug cracks in in sub 3k rounds, and average before malfunctions started occurring was between 4k and 5k rounds. The steel tip also gouges feed ramps, and the “forcing cone” of the chamber and causing feeding issues. Precision was initially better than M855.

Current lot numbers have dropped pressures a bit, but the longer peak pressure still remains, and the feedramp and reliability issue still remains (Magpul Gen 3 mags works correctly with bA1). Precision has fallen to M855 levels.

If using Magpul Gen 3 Pmags, a brand new colt or FN M4, most barrels and bolts will need replace before 10k rounds. All will start and finish with 10 round groups between 4-6 MOA.


There are uppers/barrels/bolts available that significantly increase the service life when using A1, and there is one URG that significantly increases precision of A1.

 

[Ripnbst]

That makes sense. I didn't know that the pressure levels were increased as well. I didn't understand how that tiny steel core exposed would impact the bolt life but the increased pressure makes sense. I did figure it might have an increased wear in feed ramp area but that'd be about it.

Thank you for the in-depth explanation of your initial statement.

 

[Formidilosus]

That makes sense. I didn't know that the pressure levels were increased as well. I didn't understand how that tiny steel core exposed would impact the bolt life but the increased pressure makes sense. I did figure it might have an increased wear in feed ramp area but that'd be about it.

Thank you for the in-depth explanation of your initial statement.

You’re welcome.

 

[Beendare]

Interesting discussion and what a great resource Formidilosus is as a member here.....

but its probably not the best comment post 8 to put out there on the internet.

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