You are running right @ the edge of bunnyfart loads (1000fps) & WSF is a bit slow for that. I have a friend does the same thing in his 40 w/ the same results. Bump the charge a bit & it should go away. Yes you will have more recoil @ 1100fps, but the gun will shoot cleaner, probably more accurate too. Decreasing the OAL raises pressures, like adding more powder, same thing, vel goes up. You want to get the the chamber pressure up so the powder burns more completely. If you want to run under 1050fps w/ 124gr bullet, you may want to drop a powder speed to W231 or WST if you like Win powders. Higher pressures w/ lower vel, more complete powder burn.
"Given adequate penetration, a larger diameter bullet will have an edge in wounding effectiveness. It will damage a blood vessel the smaller projectile barely misses. The larger permanent cavity may lead to faster blood loss. Although such an edge clearly exists, its significance cannot be quantified".