I have zero problems with blow back in my 45 Colt Uberti '66 Win but use big 300 gr cast bullets sized to .454 over 20.0 grs of BH209 which is 100% load density.IMO bullets .452 are dia deficient in many barrels.

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You better be afraid of a ghost!!

"Woody you were baptized in prop wash"..crossfireoops






Woody