Time to open up Gas port?

[Mik233]

Built my first 16 inch 300 blackout upper this past weekend. Went out to test it and it ran ok but not great. all brass landed in the 5-5:30 region pretty much directly behind me, so im assuming the guns a bit under gassed. I shot 110 V max, Remington 120 HP, and some 147 FMJ's but they all ejected about the same. the 147's were the worst. The gas block is on correctly, and i tried two different buffer springs, and i am using a carbine buffer. also tried out 2 diffrent BCG but that didnt seem to change anything. Would opening up the gas port a touch change anything? i will measure it soon when i am home to see the exact size of it. i have looked up this subject but have not come to a good conclusion. I will not be running this suppressed.


upper is a spikes tactical m4 stripped upper
BCG is fail zero, runs fine it other guns.
raptor charging handle,
wilson combat lightweight 300 blk 1/8 barrel, 16 inch, pistol gas length
SI free float rail
spikes tactical pistol gas tube
ergo gas block.

thanks for any info, still learning & first time messing with 300blk

[Clint]

The barrel is a good configuration from a quality manufacturer.

Measure the gas port to be sure, but I'd suspect a leaky gas block.

[Mik233]

Just checked it's at .093. Seems to be some carbon buildup/ black residue around the gas port so I'm assuming that's what it is. It's leaking. Would this call for just a new gas block?

[MistWolf]

Does it always lock back on the last shot?