Help with Marlin Cowboy 45 Colt Problem.....

[Pathfinder45]

Hi everybody; I thought this would be the best place to get answers: So, I have this Marlin Cowboy, one of the earlier ones with the 24" octagon barrel, in 45 Colt. The problem is that the chamber is large enough that I get bulged cartridge cases upon firing. I believe it's a common problem with these rifles and that the chamber is probably, "within specs"; but I think it's wrecking my brass life for reloading. So I'm not shooting it as much as I'd like to. In contrast, my Vaquero has very tight chambers and brass life is excellent in it. I read an article a few years back where Brian Pierce arranged for Marlin to furnish a replacement barrel that was unchambered so that he could have a custom chamber cut to address this problem. So, my question is; what's the latest information and cure options for this problem? Are there gunsmith that could cut the chamber off the existing barrel, cut a tighter chamber, and remount the barrel? It wouldn't bother me if the rifle ended up a couple of inches shorter. Thanks in advance for any good advice. Pathfinder45

 

[4V50 Gary]

That's not a difficult task at all. However, the magazine tube may need to be shortened so it is flush.

Also consider a barrel liner. Barrel is bored out, liner placed in and then the chamber reamed.

 

[mehavey]

See THIS POST.
As far as wrecking brass goes, I've had no problems in simply resizing to
normal diameters that still chamber/work in three other Ruger 45s.

But... take care in tightening up the chamber, that in so doing you don't
run into a reliable feed problem as an unintended consequence.