How to remove snapped off drum/bolster from Hawken rifle?

[1KPerDay]

kay... the percussion drum/bolster snapped off my CVA .50 cal hawken rifle many years ago. Thanks to the wisdom of this forum I have a new bolster ready to go in, but I have to get the remains of the old one out first.

there's obviously a hole in the center (to let the spark through). Would you:

1. drill/tap that hole larger, using reverse threads, and use a reverse-threaded bolt to try to get it out
2. use a tapered extractor or whatever to try to grip the outside edges of the hole and try to get it out
h. use a chisel and try to break the snapped off bolt into pieces and get it out that way
xiii. throw the rifle into the lake

 

[dfariswheel]

I'd go with the screw extractor.
I doubt the drum is hard enough to allow breaking it into pieces without damaging the barrel.

I'd use a big enough extractor to insure getting a good grip, but not so big you might expand the drum even tighter.
Use Kroil to soak the drum overnight and keep enough on to lube it during extraction.

 

[1KPerDay]

i'll try it. thanks

 

[Jim K]

In case the easyout doesn't work, another way is to drill the bolster out with a drill that is the same diameter as the bolster's minor thread diameter, in other words, just the right size to cut off the bolster threads without cutting into the barrel. That may require working up through drill sizes until you get the right one.

Then you just pick the pieces of bolster thread out of the barrel threads and screw the new bolster in place.

Jim

 

[Chawbaccer]

I don't know what size the original threads are, but if you could drill and tap to a bigger size life may be easier. I know you can get drums with 1/2x20 threads.

 

[1KPerDay]

Jim, some others have suggested that method also. If the extractor doesn't work I'll try that.

Chawbaccer, I don't want to mess with the interior threads. CVAs are funny in how the bolster and the breech plug fit together and I don't want to mess that up. Besides I already have the new bolster.

 

[1KPerDay]

Well I've soaked it in PB blaster for 2 days and the screw extractor still won't budge it... It gets to the point where I'm afraid I'm going to snap it off in the hole.

I don't have a drill press... I assume I shouldn't try to drill it out by hand, right?

 

[Chawbaccer]

Use a propane torch on it, I doubt you can get it hot enough to hurt the metal, and then dunk it in the PB Blaster some more.

 

[1KPerDay]

I'll try it...

 

[dfariswheel]

Drilling out things is one of those projects that sound a lot better than they work in the real world.
In a great many, if not most cases, the drill bit or the drill is not all that accurate and you wind up drilling into the threads of the barrel or other part you're trying to extract something from and wind up damaging it.
THEN you got problems.
Using a hand drill is very likely to ruin it.

If you have to attempt drilling, take the barrel to a machine shop and have them use a milling machine to drill the drum out.
Using a milling machine allows the operator to "bump" the mill accurately to correct any off-center drilling and actually get all but the threads.
They don't use a standard drill bit, they use a shorter, stiffer milling bit that drills true holes.

 

[Jim K]

A milling machine is best, but a drill press will work, with a short, stiff bit. With something like that bolster or a percussion nipple, there is a hole to follow so things usually work OK. Needless to say, take it slow and easy. The setup is important to keep the barrel rigid. In fact, the setup will (should) take a lot longer than the drilling itself.

Jim

 

[1KPerDay]

Thanks again

 

[1KPerDay]

It worked!

Bought a propane torch and heated it up nice and hot... tried the extractor again... no dice.

Heated it up again, and then doused it with cold PB blaster. tried the extractor... movement! Hallelujah!

Got the remains of the old bolster out, put some anti-seize on the threads of the new one (in case i have to remove it for some reason) and turned it in and lined up the nipple.

Ahhhh.... that feels good. I've been waiting 23 years to get this project done. I'm a bit of a procrastinator.

 

[Jim K]

The first time is hardest. The next time it may take only 22 years.

Jim

 

[Curator]

CVA rifles were made with a "blank" drum that threads into the barrel but has a tapered "cone" that intersects with the breech plug, locking it in. Once this is installed the nipple hole is drilled and threaded, and a hole is bored into the breech plug through into the drum (down through the barrel), connecting to the flash hold drilled under the nipple. It sounds complicated, but is very strong and is easier and cheaper than installing a patent breech. Installing a pre-made drum does not guarantee that all the channels line up. I have attempted drum relpacement on several CVA rifles and a few of them lined up sort of OK. The others were way off. Withthose it was esier to cut off the barrel at the breech face and re-thread and install a patent breech plug. It sounds as you got lucky--keep up the good work!

 

[1KPerDay]

That was a consideration, and I haven't tried it so I don't know if the spark will actually find the powder. However, blowing down the breech does force air/oil out of the nipple, so I have some hope. I just really like that brown barrel and it took a lot of work so I didn't want to replace it with a CVA one that had been drilled properly in the first place (this one wasn't; I had spotty ignition, and a "gunsmith" removed the bolster, drilled it like a hamfisted monkey, and reinstalled. It snapped off the first time I shot it afterward and it sat ever since).