Are you shooting sub sonic ammo through that silencer?
I have. I dont most the time though. My sub load is a 70gr Speer with somewhere around 4.5gr of trail boss. Dont trust that though I had a round or two during testing that didnt exit the barrel! I checked the bore with a push rod after every shot if I even had the slightest question. Work that load up with a chrony without the can and get it just under sub sonic. Thats the safest way. With sub rounds it is very very quiet. No bolt cycling. Just a "pfft". It would hold MOA at 100 too! If I remember right it was 12MOA lower than my standard load at 100.