My 4" M25-5 had .457" throats and didn't shoot cast worth a crap. Jacketed did better. I sent it to Smith for a cylinder swap and received a .453" throated piece. I shoot .452" RCBS 270 gr SAA's at 800 fps. I had Jim Stroh build a tight chambered 5" 45 Colt that was a mix of a M29-2 and an 8 3/8" 45 Colt barrel. Same load, stupid accurate.
