Final verdict on ADCOM M855

[Heavy Metal]

I fired 100 rounds of 98 HS ADCOM the other day and had one poppe dprimer. The primer pocket was enlarged on the casing and the primer itself had the firing pin indent pushed out by the pressure. The primer was stuck on the bolt face.

My rifle is a 5.56mm chamber and previously had over 6000 (proabally closer to 7) rounds on it with ZERO popped primers including shooting mil spec stuff on 90+ degree days.

This was the first popped primer ever with this weapon and my first popped primer in eight years.

I'll pass on more. Beware

[Low Drag]

I chronographed some of lot. no. AML98M010-001 yesterday in my 16" RRA carbine.

AV 2933 fps
HI 2974 fps
LO 2899 fps
ES 76 fps
SD 22.9

The couple of groups I've bothered to measure were in the 3 to 3-1/2" range at 100 yards. They were shot with my elbows on the table, no sandbags, bipods, etc. Sighting was through an EOTech 512.

I've noticed a few flattened primers out of the 120 rounds I've fired. Thankfully there haven't been any that pierced or caused catastrophe. Probably 60 to 70% had obvious dings or significant scratches in the brass before firing.

I doubt I'll be buying more.

I've chronoed 98 lots from my 16" Bushmaster and came up with results close enough it's not worth the trouble to post.

I also get good group with it at 200 yds with open sights (from the bench) and it shoots about 3" lower than Q3131.

[SGB]

I picked up 100 rounds of the 98 headstamp to try out. I started out using a rifle built with an Armalite HB with a .223 chamber and got two popped primers out of 20 rounds with several other casings showing flatened primers.

Fired the other 80 rounds out of two bushmaster and one colt all with 5.56 chambers and had no popped or flatened primers.