Author Topic: leaking cva drum/barrel joint (Read 568 times)

Lug · « **on:** May 28, 2006, 04:05:16 PM »

I went to a shoot today, used my brother's CVA Kentucky rifle in .45. It is an older rifle with the Jukar barrel. When I was cleaning it this evening I noticed that there is a leak between the bottom of the drum and the side of the barrel. Since there was already marks on the drum where a previous owner had used a pipe wrench or water pump pliers on it I removed it and inspected the threads. There isn't any noticeable, by the naked eye, defects. I am wondering what my options are for repairing it. Thinking that a possible fix would be to helicoil the hole in the barrel and installing a new drum. Is it possible this rifle barrel was origonally a flintlock barrel and the drum they used doesn't fit very well and maybe just a new drum will solve the problem?
Justin

captchee · « **Reply #1 on:** May 30, 2006, 04:03:18 AM »

pretty common for those rifles to do that , we forget just how old some of them are .
if it were me i would purchase a blank drum with threads one size bigger . I would also get an alignment jig . It will save you a lot of time .
Re tap the barrel for the new drum then drill and tap the new drum for your choice of nipples sizes

captchee · « **Reply #2 on:** May 30, 2006, 04:05:33 AM »

pretty common for those rifles to do that , we forget just how old some of them are .
if it were me i would purchase a blank drum with threads one size bigger . I would also get an alignment jig . It will save you a lot of time .
Re tap the barrel for the new drum then drill and tap the new drum for your choice of nipples sizes

spitpatch · « **Reply #3 on:** May 30, 2006, 04:48:57 AM »

Lug, Captchee is giving sound advice. That's the best thing you can do short of rebarreling it.

Lug · « **Reply #4 on:** May 30, 2006, 06:55:56 AM »

Are the threads on a drum normally machine threads or are they pipe threads? Normal machine (bolt) threads do not seal, but require that there be a sealing surface i.e. body of the drum screws down and touches the flat of the barrel. The hole for the drum in this barrel is slightly larger then the flat it is drilled into, thus there is an area where the drum doesn't touch the flat and this is the leak area. Any idea of what kind of pressure there is when a .45 is torched off?
Justin

captchee · « **Reply #5 on:** May 30, 2006, 02:56:59 PM »

Even though the circumference of the drum is bigger then the flat it rests on it has to seal .
Some CVA bolsters have a small sealing surface older ones do not and still others have a threw type neck that seals to the opposite side of the bore and has only a small hole in the side of the neck to allow ignition . These are normally on newer models of CVA . I would have to say these also contribute to the majority of ignition problems
As to the pressures . that all depends on the load . Pressure itself isnt really the problem though , the problem is the leak .
The leak allows spent powder to come through or across the threads . The fouling is corrosive and will eventually damage the threads to the point that the pressure will remove the bolster . What pressure it will take to do this ? Hard to say , it all depends on how long it is before the problem is fixed