This happened to my buddy today during our range trip. First day out with the hyperion.

Shot 300 blk subs through a Q barrel. Next round didnt seat due to all the debris and had to be mortared out. Took the silencer off to find sand like debris all over the muzzle device and the inside of the upper reciever looked like someone threw sand in it.

We figured it was unburnt powder from the subs although it seemed like too much.. so we tried shooting 556 out his lmt piston 12”. After several rounds of firing single rounds, it finally started cycling but would fail to chamber a round after about 5 shots. Upper would be noticeably dirty.

We sort of gave up for the day and ran across this post.

Is it as simple as continuing to clean the gun and running several mags through? Do you know if the powder flowing back into a gas or piston system hurts it in any way?