I shoot a Pedersoli 'Colt Lightning' in .45 colt, and admittedly, would have bought it in 44-40 if I had to do it again. When I started with it, I experienced 'blow-by' for sure, and it was annoying and distracting during a stage. All that is gone away now, as I shoot 250 gr. bullets and full loads out of it now, without bow-by. When I say full loads, they are still within safe parameters and pleasant to shoot, and accurate too. I won a speed rifle match last year at a shoot in Alberta, Canada, against all comers with their tricked out short stroked whatevers. I love this rifle. Annealing the case mouths would just make these cartridges and rifle even better.