Replacing a Barrel

[greymount]

I currently have a 45 caliber Vincent half-stock rifle with a 7/8 strait octagon Green Mountain barrel.  I am a little concerned about the safety of the drum in a 45 caliber. What I would like to do is replace this barrel with a 36 caliber Colerain 7/8 strait octagon barrel.  A much thicker wall and the caliber is more common in the Vincent rifles that I have seen.  The threads in the breech plug in the Green Mountain barrel are the same as the threads on the Colerain barrel.  Can this be completed without major issues.  The tang is that narrow pointed tang that is common to Vincent rifles.  Would this create a problem with my tang mortice. The current fit is perfect with no inletting gaps whatsoever. 

[jamesthomas]

 A .36 cal. in a 7/8th inch barrel would be a pretty heavy barrel!, not something I would want to tote around in the woods. JMHO.

[smylee grouch]

That 7/8-45 is safe to shoot if put together right. I had a 36 in 7/8 barrel and it was on the heavy side but did hold nice for off hand shooting. I also had a 40 in 7/8 and that is what I would suggest over a 36.

[FALout]

You should find someone near you to take a look if you are unsure of the rifle.  The drum should be fine unless you mess with it too much besides changing nipples.  Can the barrel be replaced, yea.  Once again, if unsure of your own work (or if you have never installed a breach plug) I would find someone to do it for you.  If the drum is not installed correctly (new one might be better/easier), there could be some adjusting of the hammer that may need to be done.  Good luck with whatever you decide to do.

[Acer Saccharum]

If the drum threads are sloppy, it is unsafe.

A suggestion that is easier than replacing the whole barrel:
You could make a new drum with larger threads, but this might require a larger diameter on the drum body. The lock plate would need to be fitted again to the drum.

If the drum is not supported by the lock plate, it will eventually shoot loose from all the impact from the hammer.

[greymount]

I was planning to have someone check the drum for safety before I shoot it. However,  I would rather have the gun in 36 caliber.  I would use the same breech plug because the threading is the same on the 36 cal barrel as on my current 45. The tang fits perfectly in the tang mortise now. My biggest concern with changing the barrel is a possible problem with the tang fitting in the mortice and having gaps. Would using the breach plug on a different barrel change the fit in the tang area of the gun? The tang is a common Vincent one that tapers to a point. I would assume that having both barrels in 7/8 would not effect the barrel fitting in the barrel channel.

[smallpatch]

Tang fit shouldn't change.  You will have other issues that will be a challenge.  Underlugs, under rib, keys or pins, etc.
These are not impossible to overcome, but need good planning.

I echo Acers suggestion. 

[Mike Brooks]

I just the caliber change is the real issue I'd have Hoyt line it to a .36. Everything stays the same then. Probably cheaper to do too.

[Pete G.]

You could shorten it at the rear and install a patent breech.

[flinchrocket]

Another issue with changing to the 36 cal. is the ramrod. 45 cal usually use 3/8 rod and that's to big
for a 36 cal.

[smallpatch]

Mr Brooks has the best answer so far!!