u/Old_Version_1932

I just built this AR-9 and I am looking for a little help. On this build there is no bolt hold open for last round. when the last round is fired from the magazine the follower in the magazine is struck by the bolt with such force that it is becoming dislodged and damaged. The only cost effective solution is to load a snap cap in my mags. Is there any other solution other then buying a different upper that will activate the bolt lock?

build

Foxtrot Mike VFM -9 complete upper

aero precision EPC-9 lower

CMMG LPK

KAK shockwave tube and pistol brace

kak 10oz buffer

31 coil round carbine spring

CMMG. zeroed 36 can