Leaking breach plug on CVA mountain 45 caliber #11 percussion cap pistol

[tooguns]

Width across the flats is flat side to flat side, not width of the flat part. Common mistake. Probably 15/16 atf. Try a search of CVA replacement parts in the web, see what turns up.
Probably best to replace the whole barrel assembly.

[Steeltrap]

I realize this is not a direct help to the OP. But it is about CVA products.

Earlier this year I decided to finally build a flintlock around a CVA barrel that I've had for years. It was originally a percussion and I wanted a youth rifle.

So, I cut part of the barrel down and then used a section to fab a hook-breach. When I cut the barrel for the hook breech, this is what I discovered inside the barrel. (I bought a new barrel BTW)

[Hungry Horse]

 I wouldn’t waste a lot of money on a CVA anything. If it were mine, and I wanted to shoot it. I would cut the breach off, forget the hooked breach, put a plain fixed tang on it and just shoot it. That gun in .45 cal. Is a boat anchor to start with.

 Hungry Horse

[hudson]

I would suggest forget a new original type breach plug as the seat in the barrel could and probably is bad. Cut off and re breach maybe. Maybe this should be a separate thread but sort of fits. I went through $#*! with a Rigby replica not a quality brand but otherwise nice bullet rifle and yes not of us make and yes the price was right supposed new. Up on firing for the first time I discovered a Leek at the breach plug. Un breached and found a gap between the face of the plug and the seat, set the barrel back and refitted the breach plug. Fixed no! Set the barrel up in the lathe and re cut the seat. Fixed no! I made a new beach plug as I recall the threads had quite a bit of a taper. Fixed no. OK cut a recess in the face of the breach plug and made a copper washer and fitted the breach plug really tight. Work NO! After a lot of thought and fine measuring it was determined the barrel was probably clamped in a vice and hand taped at an angle. The barrel wall is pretty thin so chasing the threads maybe a safety issue. Project has been sitting in the corner for a few years there will be a new barrel one of these days.

[WECSOG]

I have one of those in .45 caliber. Barrel is 15/16" atf. I've had it for ~45 years and have fired it quite a bit, often with heavy loads. No breech leaks that I have ever noticed. I do have a CVA Philly Derringer (different breech design) that eventually developed a breech leak. I welded and ground it and have occasionally fired it that way with light loads with no issues. But I have since bought a new barrel for it.

If my Mountain Pistol ever did this, I would probably do as someone here suggested: cut and re-breech the barrel. Probably lose the hooked breech. Or, maybe fit a better quality barrel to it.

[Dphariss]

I realize this is not a direct help to the OP. But it is about CVA products.

Earlier this year I decided to finally build a flintlock around a CVA barrel that I've had for years. It was originally a percussion and I wanted a youth rifle.

So, I cut part of the barrel down and then used a section to fab a hook-breach. When I cut the barrel for the hook breech, this is what I discovered inside the barrel. (I bought a new barrel BTW)

I wish Jim Kelly were still around to comment.
This is what happens with low grade, “free machining”/cold rolled steels are used. But people don’t want to hear it.

[bpd303]

My suggestion is for the owner of the pistol to remove the barrel from the stock and take some close up pictures with good lighting of the breech and bolster from several angles, so we can stop guessing about the problem.
I have removed the bolster and also the breech plug on three CVA rifles and had no trouble reinstalling them. I even converted a percussion 50 caliber to a flintlock, using the original breech plug.
The thing about invalidating the warranty is a moot point seeing as CVA is no longer around.
 If you are close to me, or anyone with experience working on muzzleloaders, with hands on inspection it would not be hard to diagnose the problem. Or better yet call Deer Creek Products and make arrangements with Jim to send him the barrel.

Here is a link to one thread I posted on the Muzzleloading forum. If live links are not allowed and it gets removed send me a PM and I'll send it to whoever is interested. Or search for CVA Hawken for the record books.

https://www.muzzleloadingforum.com/threads/cva-54-hawken-for-the-record-books.95771/

Randy aka bpd303

[bpd303]

  That gun in .45 cal. Is a boat anchor to start with.

 Hungry Horse

Not a very good one I might add not enough weight or mass.

Randy aka bpd303

[Hawg]

  That gun in .45 cal. Is a boat anchor to start with.

 Hungry Horse

Not a very good one I might add not enough weight or mass.

Randy aka bpd303

Trot line weight.

[WECSOG]

I don't consider mine a boat anchor at all. I'm a fan of .45 caliber muzzleloaders, and have several of them including CVA Mountain Pistol, Kentucky Pistol, Colonial Pistol and Philadelphia Derringer.
To each his own, though. It's all good as long as we're enjoying the hobby.

[Hefner]

I had exactly the same problem as Hungry























I had exactly the same problem as Hungry Horse with my 50 cal. Mountain Rifle back in the 1970's. That is leaky threads on the drum.  My solution at the time was to braze around the base of the drum, which worked for a short time.  The problem with this was that in order to reinstall the lock properly, I had to file the excess braze material which eventually led to more leakage.
I did actually solve the problem by sending the barrel back to CVA. They sent me a new replacement barrel!!
Steve Hefner

[Hungry Horse]

Hefner; I think you misunderstood me, my CVA Mountain Rifle burned all the treads out of the drum where the nipple threads in. But I did shoot sixteen pounds of powder through it in a couple of years.

Hungry Horse

[Bob Roller]

Buy a welder's face shield if you are going to shoot it as is ..That type of gun is designed to sell and had no appeal to a better market.
Bob Roller

[Daryl]

Hefner; I think you misunderstood me, my CVA Mountain Rifle burned all the treads out of the drum where the nipple threads in. But I did shoot sixteen pounds of powder through it in a couple of years.

Hungry Horse

Interesting. Obviously a VERY poor fit and/or design. I put 25 pounds of powder through my .69 in one year - no problems. That was about 30 pounds of powder ago.
I would suggest that barrel and breech are KAPUT!
Still shooting it (the .69) regularly.