Even the 44MAG has bitten lots of folks, probably even lessor handgun cartridges. IMO just technique is why, or the lack of it.
The 454 bitter I mentioned was an Encore 12" - one of the barrels I also bought for the frame/grip only right when they first came out (plus 7BR, 223 and 22-250 15"). Mike was no slouch at all shooting handcannons way nastier than a 454 Casull one-handed. Had no problems with the FA 454 at all. But with it being a near new rig all I had was the unusual very high grade wood but otherwise poor design factory grip, only a custom longer/heavier forearm to match the grip more for the longer barrels at the time, and with the hot ammo the 454 was a torquemeister. He had the right techniques down solid I'd learned decades before him from long experience with all handguns, including the Contender's biggest and baddest wildcats, XP-100 and Wichita bolters. So he probably just let it get away from him because he didn't realize I was slightly changing my technique to include some control at the shot. My normal technique with all handguns was mostly just a thumb/one finger hold always used for even the handcannons where I just went along for the ride from the shot and didn't control them during follow through much more than enough to not drop them until at the end of recoil. This particular rig/ammo was easier with some control at the shot because of the torque. Weird to me anyway from just a 454 - never bothered to check the bore, etc to see if it got out of TC not up to specs because it shot accurate just fine for me. He never shot it again after even after I soon got a custom grip made for it when I added a custom 10" 416 Rigby barrel. He wouldn't shoot the new 416 barrel either while I shot it one-handed no problem at all. Once bitten twice shy I guess as I don't remember him ever getting an Encore despite really liking his Contender's.
