I loaded these light with 110 grain bullets and 4.6 grains of HP-38 which the charts show as a beginning load. All the casings were cleaned, sized, flared, primed, loaded with powder, bullets seated and crimped at the same time so deviation I assume is not from that aspect but who knows? From the posts so far I gather I was way too close to the chronograph at 3.5 feet and muzzle blast is probably the problem. I was afraid I might shoot the chronograph at a longer distance!
I'll try some more rounds this weekend with the chronograph further away. Hopefully I won't wound it in the process!!!