.300 Blackout brass looks beat- opinions please?

[CoopsDad]

I built a .300 Blackout upper for a lower my son has. I used good parts I picked up at the Fort Worth gun show and Gatesville gun show; it shoots great with 147 grain BTHP but the brass looks a little more chewed up than on my .300 BO. It's a 16" with a carbine length gas tube and a non-adjustable gas block. The gun throws the brass pretty much straight out to 1:30 and it's dead accurate. I sighted in at 25 yards then moved to 50 yards, and the thing just puts three in a row in a sweet cloverleaf with all the holes touching.

The only qualm I have is this bit of ugliness it leaves on the head. Any opinions would help.

Thanks!

IMG_20200711_182307054.jpg

[nate76239]

It looks like the ejector could be sticking or binding and not fully compressing inward.

[baih777]

How many times have you reloaded that brass ?

[AlHO1966]

Reloads? How many rounds through the rifle?

I havent started reloading 300 Blackout so if I had a gun running well and shooting as accurate as yours I wouldnt worry about it.

[FeuerFrei]

Looks like soft brass / over gassed or both.

Swipes on the base are usually the tell on a 556 rifle.
Brass particles in the action too. Shaved off from the rims.

Sans adjustable gas block you can try to slow the bcg down by using a heavier buffer or stiffer action spring.

[CoopsDad]

The brass has been reloaded 2 or three times; some of the necks are beginning to split so it's the last time through the wringer for these.

I figured it might be a little overgassed but everything works so well on this little carbine. I'd hate to throw a wrench in the works by starting a swap out. I'm reloading with 16 grains of H110 and seating to a COAL of 2.060". That load works great in my gun, shoots accurately and consistently. It seems to be a great load for this one too but the brass. Ugh. Oh well, the price you pay to keep nice things running.

[sammy]

The primer doesn't indicate high pressures but that ejector wipe is way too aggressive. Try a different bolt if you have one or replacing the ejector spring. Easy stuff first.

[CoopsDad]

Reloads? How many rounds through the rifle?

I havent started reloading 300 Blackout so if I had a gun running well and shooting as accurate as yours I wouldnt worry about it.

I just got the gun put together last night and fired it the first time today; maybe 50 rounds. All 147gr BTHP on 16 gr of H110. I'm blessed in that this is the only thing that isn't perfect on this build. But that's also the reason I'm so focused on it.