Jsb beast in 22 cal 33.95 grain

New here, but years of experience with long range rifles, recently bought a 22 cal Condor. Never shot it before adding a homemade suppressor that weighed 10 oz. At 40 yards the 33.95 JSB's between 900 and 935 fps were shooting consistent 1/2" 5 shot groups. I then bought a TT Condor Shroud and the groups immediately opened up to about 4" at 40 yds. I came to the conclusion that the barrel harmonics of the Condor barrel with the 33.95's is horrible without stabilization, so I put three shims between the adapter of the TT shroud and the barrel itself, and the groups went back to a little over 1/2". More experimenting to follow.

Dave