Personally I like the 5 1/2 bbl. Bisley frames, that said my FA 454 has a 7 1/2" bbl that I often wanted to shorten but it's just so accurate the way it is didn't want to mess with perfection. My Linebaugh 45 has the 5 1/2" which does not have excessive muzzle flash but then again it's not a 454. I had a SBH in 44 mag that mag-na-port worked over years ago and that was cut to 4 5/8", again no great shakes with the muzzle flash. I just ordered a BFR in 500 Linebaugh with the 5 1/2". In the end I think you really can't go wrong either way.