My original barrel (late 70's .54 cal. Mountain rifle) got rusted up after a few years living back east. I've checked out the obvious vendors including CVA, and can't find a drop-in replacement barrel. Will a Lyman Great Plains barrel work?

Feedback is appreciated.  Thx

no it will not..the lyman great plains barrels are made by investarms in italy.

look here

You can have your barrel re-bored to a larger caliber. Bob Hoyt is one of the most recommended for the job. You should be able to take that barrel out to .58. Talk to him about it. I'm not sure what he currently charges, last I heard it was around $60.

717-642-6696

Thanks for the link! I have an old .45 caliber CVA "Mountain rifle" that I would love to convert to .50 caliber........

Find the outside diameter of the barrel.  You can buy a replacement and fit it yourself.

Pulling a breechplug isn't hard.  All you need is a large crescent wrench (OK, for a Spanish Markwell Arms I used a Mauser action wrench and its weight alone was sufficient to loosen the breechplug).  Measure the threaded portion of the breechplug, threadpitch and diamter and tap the barrel to match.

The dovetails for the underlugs may be cut with a hacksaw and file.

Drilling a hole for the drum is easy, but removing the old drum may be tricky.  I'm making aluminium jaws for my barrel vise so I can remove drums.  The jaws can also be placed in a vise.  Timing the drum such that the hammer falls on the nipple is a bit trickier.

Thanks for the feedback and info!