CVA / T/C Thompson Centre / Investarms Hawken Rifle problems

[pointfive0]

Hello everyone and thank you in advance for the great advice! I know someone here will be able to help, and hope to meet someone in the Oshawa / Toronto Canada area with the same gun!

I'm sure the kit gun builders out the are the ones that will be able to help me.

My gun is actually a Euroarms, made by Investarms, but is identical to the Thompson Centre .50 cal Hawken except the engraving on the lock plate. It was made around 1977, .50 cal, 1:48 twist, 28" barrel.

I've googled "Thompson Centre problem" and have found many problems, most of which I have, and more. Here is a new one as of yesterday:

For some reason the barrel is not fitting properly anymore. Every time I take the barrel off to clean it, it becomes more and more difficult to reassemble the barrel hook on the tang (in other words I can't assemble the barrel on the stock easily).

Yesterday was the breaking point. The barrel will just not sit properly anymore. The breech hook doesn't want to grab right. I am thinking the entire fit and finish on these things is off because of the foreign wood used. I believe it's some type of mahogany. I'm thinking because it was made in Italy, it was not acclimatized in this area BEFORE being machined, and the wood is moving / twisting around a bit, causing the hole spacing and cutouts to be off. (This may no longer be a problem as the new Thompson Center guns are advertised as being "solid american walnut")

This may explain why the hammer on my gun is misaligned, causing misfires, which was never a problem for my father 30 years ago when he bought it new.

I took the breech plug tang off completely for inspection, don't see any damage, only wear from swiveling in and out, which I'm guessing is normal. I connected the barrel to the tang and tried assembling them on the stock as a pair, but I have to force the barrel down lightly (about 5 lbs of pressure) to be able to insert the wedge pin. I'm certainly not deforming the barrel, but there IS tension holding it down, and I DON'T like this! I have no idea what to do next.

Has anyone ever built a CVA Hawken kit gun like this? If you're out there, you can probably help me.

This gun has been babied. It is near MINT condition, with no signs of wear, barely a scratch on the thing. Always kept clean, oiled, and stored horizontally.

It constantly misfires. I've changed nipples three or four times now with no improvement. 2 caps are fired off every time I go out. Gun is cleaned with alcohol prior to first shot, and cleaned with alcohol between each shot, followed by dry patches. As per my black powder loading manual, I'm using 70gr FFg with .490" round ball, .010" patch, and grouping was all over the map, and all of a sudden with the use of alcohol I've brought it down to 6" groups at 50 yards, a dramatic improvement!

Problems I still have with gun:

-Percussion caps are never consistent (purchased musket nipple, and musket caps on order!)
-the hammer is off centre (too far back) causing missfires and hangfires?
-the powder doesn't always get down into flash channel even with 4-5 good raps when pouring powder, further causing missfires (maybe drill it out one size bigger?)
-I've had to offset the rear sight about 1/8" to the right to get any kind of accuracy
-brass pieces on loading rod have unglued themselves on both ends (thread and loading end) solution: cross drill 0.060" hole through brass and wood and insert solid brass nail and peen end (home-made rivet)

I unscrewed the breech plug today to get a good look at it, and get some real light in the barrel, and everything is flawless and clean as a whistle. Barrel is MINT, Channels and holes are very clean.

I totally dismantled the lock to see if there was any way to adjust it and apparently there is not. I'm about to wrap this thing around a tree.

Thanks again in advance!

 

[rafterob]

The stock may have some warp and that would explain having to apply some pressure to be able to install the wedge. That is not really a problem and should correct itself as weather changes. It could be due to the stock having "dried out" in which case rub the barrel channel up good with linseed oil or the like. That may also explain why the tang and hammer are suddenly mis-alligned. When you take the barrel out do you loosen the tang screws to allow the tang to swing up slightly? That is the proper method. Install the barrel and wedge and then lastly tighten up the tang screw(s). Improper hammer alignment is a common issue with the factory guns whether they be kit or not. Carefully check to see if the hammer is clearing the cap or if it is hitting the edge. If it is clearing the cap then a slight mis-alignment doesn't matter. The other options are to try to bend the hammer or to grind out the front of the lip on the hammer. If the hammer is clearing the nipple then there is probably some issue with the lock being compromised somewhere during its range of motion.

 

[rafterob]

When you say it misfires, do you mean the cap goes off but does not ignite the charge, or the cap does not go off?

 

[pointfive0]

Both. Cap fires no ignition or cap doesn't fire at all.

Thanks! I will loosen the tang screws when removing barrel from now on!

 

[Zonie]

Welcome to the Forum.

As you know, your gun is not a Thompson Center gun. The TC's have always been made in America.

IMO there should be a slight upward pressure on the barrel at the wedge. This is not a bad thing.

On older hooked breech guns it isn't uncommon for the rear tang block to move lower into the mortice. This can happen because the wood under it has compressed over the years.
If this happens occasionally the hook on the breech of the barrel can start to run into the wood behind the tang block. Check for an interference by lightly coating the hook on the barrel and inserting, then removing it from the tang block. Then remove the block and look for signs of lipstick on the wood. If it is there the wood should be cut back a little bit.

You didn't say what powder you are using. If it is a modern black powder substitute some hang fires happen.

I suspect that you are using too much alcohol for your barrel wipings. The wiping patch should be damp, not wet. If it is too wet the alcohol will run back into the flame channel that connects the breech with the nipple. This will wet the powder and prevent it from being blown back thru the flame channel during loading.

Also, if you are loading with the hammer down on the nipple or you are loading with the spent cap still on the nipple the air flow thru the nipple will be greatly reduced and this also can cause the loose powder to fail to be blown back under the nipple while loading.

Sometimes over tightening the lock screws will cause the lock plate to be mis-aligned which can cause a mis-alignment of the hammer with the nipple. This is usually a side to side problem with the alignment so it may not be your problem but its worth remembering that the lock screws should not be overly tightened. Just snugged up will do.

 

[airmansteve]

I have a CVA hawken that I built from a kit. I found that difficulty in getting the barrel back in has been caused by the lock plate screws being too tight. I solved the problem by loosening the lock plate screws, inserting the barrel and wedge, then tightening the lock plate. Perhaps this is also related to the hammer misalignment issue?

 

[pointfive0]

Thanks again folks. I'm still messing around with it, trying not to make any modifications until I really figure out what's going on. Just about to try the lipstick. I can clearly see that the drum is not sitting right, about .050" too far forward, which would cause the hammer to be too far back. I'm convinced the lock plate assembly moved back somehow or the tang moved forward.

 

[pointfive0]

I think I may have found the problem. The breech seems to be bulged on at least 3 sides. It is bulged ever so slightly, maybe .050". When I first took this gun out, I shot about 15 shots without cleaning between shots. Didn't know any better. Last ball became stuck halfway down the barrel. Out came the screw, it broke off the ramrod, I went home.

Now that I've read my black powder loading manual, the author mentions how pressure builds up if you don't clean between shots. Maybe excessive pressure caused the breech plug to bulge, causing a slight misalignment in the barrel assembly. I think I may have to order a new breech plug or bend the hammer a bit

 

[Zonie]

Hopefully you meant to say it was .005 (five thousandths) larger and not .050 (fifty thousandths).
Then, .005 wouldn't have any effect on how the barrel fits into the wood. :hmm:

Seriously, if you stuck the ball half way down the barrel and fired the ball out without first seating it on the powder charge there is a good chance that you bulged the barrel.

As your original post implied that you have loaded and fired the gun I will ask you this important question.

When you were loading a recently fired patched ball down the barrel did it suddenly seem to get "real easy" to shove? Almost like it was loose?
If so, your barrel may look like new but it has been badly damaged. Damaged to the point that it may be dangerous to fire.

If on the other hand the resistance to the patched ball is fairly constant as it goes down the bore you have not bulged the barrel and it is not the cause of the barrel fitting the stock poorly.

As for replacement breech plugs, unless you can find one with metric threads your out of luck.
There is also a good chance of messing up the barrel when you try to remove the existing breech plug. The big factories tighten them VERY TIGHT.

 

[pointfive0]

Only the breech seems bulged. I DID mean .050" and not .005". It may only be about .025" but there is definitely a bulge on three sides of that breech. The barrel is still as tight as the first time I loaded it 50+ shots ago.

I did not shoot a ball half loaded. The first session I shot this gun the ball got stuck half way down, and I broke a ram rod trying to remove it, but I did know better than to just shoot it out. I had a weld shop weld an air hose fitting to a nipple and blew the ball out.

I was fortunate enough to be able to unscrew the breech a few days ago with about 50 ft.lbs of torque. I had no choice as I had a brass brush covered in solvent break off down there. It was a brand new T/C .50 cal muzzleloader brush, and I guess I should have softened it up a bit, as it only went in one way. I tried twisting the brush out but the steel stem just popped out of the aluminum crimp. Seems kinda cheap to me but lesson learned: stick with .410 bore brushes.

As you can tell I'm having bad experiences with muzzleloaders. Some are my fault, some are not. Lessons learned all over, and hey, I'm still having fun and staying out of trouble with this hunk of steel!

 

[Zonie]

I'm glad to hear you didn't shoot it out. :thumbsup:

Of course you aren't going to get another brush stuck but if you do get a bore sized piece of copper, brass, steel or PVC tubing that will reach to the breech of your barrel and drive it down over the brushes bristles. The brush will then come out when you remove the tube from the barrel.

 

[shootrj2003]

I wish I could see what you are really saying,Because a beech is stronger [I think,somebody correct me if I'm wrong]the stronger of the two and beyond that if it got bulged the barrel is probably effected also ,in any case an ispection by a knowledgable person is called for 1.somebody who knows muzzleloaders well,who will tell you,if it is bulged ''see a gunsmith!'' or 2. preferably, ''see a gunsmith'' [a bit of serious humor]but seriously have it looked at ,It will cost you little if your wrong but if your right it could cost you and maybe the guy next to you a lot, be careful. shootrj