Addicting
Well-known member
Look up firing pin O ring on the google machine.optima v2 with bh209 powder
On those rifles the firing pin bushing screws in and out. That can be adjusted with a shim or o-ring. That an have a direct impact on your accuracy. If your getting blow back of any type from the 209 there is room for adjustment. You can dial in your groups just from that adjustment.