Need help with CVA Mountain rifle lock

[renegadehunter]

I have an old "made in the USA" CVA Mountain Rifle.
Long story short, it was built from a kit by my wife's grandfather. It was his first and only one he's built. After completing it he didn't know anything about shooting them and just hung it on the mantle. He has now given it to my FIL. My FIL has never shot a muzzleloader and brought it to me to check out and develop a load for it.
I noticed right away that the wedge pins pretty much will just fall out, so I shimmed the stock under the barrel and have them fitting tightly. I mention that it is his one and only build and that the wedge pins were really loose to share that the lock and set trigger problems I've noticed may very well have to do with the inletting he did.

The set trigger wouldn't set at all when I first received the rifle, and I also noticed that the hammer doesn't stay in the full cock position very firmly...some forward pressure on the hammer results in it letting the sear pop out of the notch and it drops clear to the nipple.
I did some reading and found the trigger adjustment recommendations. I cocked the hammer to full and then adjusted the screw between the triggers until the hammer released, and then turned it back out one full turn. This resulted in the hammer staying at full cock much better, but I can still push forward on it and it will let the sear pop out of the notch and drop the hammer all the way to the nipple. I have tried adjusting the screw out even further than the one full turn but it doesn't change the hammer not staying better. The set trigger will set once in a while, but sometimes it won't catch. If I push forward on the front trigger a bit the rear set trigger will set every single time. It seems like the front trigger isn't firmly staying all the way forward. There is a hokey looking little wire on the very front of the trigger assembly that looks like it possibly is supposed to contact the arm of the front trigger and help hold it all the way forward? But messing with it didn't seem to improve anything.
With the triggers removed from the stock and held upright as they would be in the stock the set trigger still won't set every single time unless the front trigger is pushed forward a bit.
Far and away my biggest concern is the hammer not staying solidly in full cock position. Out of the stock it seems to hold fine. By my eye the sear appears to be all there and the end isn't chipped or missing.
I'm hoping someone has some adjustment setting ideas that may help.

 

[mooman76]

This was a common problem back when these were made. Your initial assessment was correct. The trigger is inlet too deep but that was from the manufacture that way. Shim the trigger out and that should fix your problem. The Wedge pin can also be fixed by setting the pin on a flat surface and tapping it lightly with a hammer. It bends easy so tap lightly like I said. If it needs more just give it another tap. Also you may notice if you set the gun down hard on the butt, the trigger will probably fall then until you shim out the trigger a little.

 

[firestick]

On my .50 cal I had to shim the trigger out. It is a common problem with the kit rifles that they are inletted too deep and it affects the working of the lock properly. I experimented with cut up credit/bank cards etc before deciding how thick I needed and then fit a wood sliver the right size and thickness and glued it into place. Without doing this no amount of adjusting or screw tightness would affect the lock properly working and trigger set nor hammer set.

 

[renegadehunter]

Moonman76, thank you. The wedges were so loose that you'd have to bend them so much that they wouldn't go through the escutcheon on the far side without bending it. That's why I decided to shim the inside of the stock where the barrel sits instead. It appears it has done the job, as long as it'll shoot accurately. Thanks for the shimming the trigger out info.
firestick, thank you as well. Did it require being shimmed out more than the thickness of one piece of credit card?

 

[mooman76]

I just used a washer to shim mine out. Probably twice as thick as a CC.

 

[firestick]

Mine took 2 pieces of the card to get it out far enough. Used some scrap oak for the wood sliver I made.

 

[MO_E_W]

Another way to shim the trigger assembly on the CVA Mountain Rifle.
I used a flat head screw to shim/stop the trigger assemble.
This way I could fine tune the depth of the triggers.

MO

 

[MO_E_W]

Location of return spring on front trigger assembly.

MO

 

[sdilts]

I have tightened the wedge fit before by tapping the underlug itself.

 

[Grenadier1758]

I have an old "made in the USA" CVA Mountain Rifle.
...

The set trigger wouldn't set at all when I first received the rifle, and I also noticed that the hammer doesn't stay in the full cock position very firmly...some forward pressure on the hammer results in it letting the sear pop out of the notch and it drops clear to the nipple.
I did some reading and found the trigger adjustment recommendations. I cocked the hammer to full and then adjusted the screw between the triggers until the hammer released, and then turned it back out one full turn. This resulted in the hammer staying at full cock much better, but I can still push forward on it and it will let the sear pop out of the notch and drop the hammer all the way to the nipple. I have tried adjusting the screw out even further than the one full turn but it doesn't change the hammer not staying better. The set trigger will set once in a while, but sometimes it won't catch. If I push forward on the front trigger a bit the rear set trigger will set every single time. It seems like the front trigger isn't firmly staying all the way forward. There is a hokey looking little wire on the very front of the trigger assembly that looks like it possibly is supposed to contact the arm of the front trigger and help hold it all the way forward? But messing with it didn't seem to improve anything.
...
Far and away my biggest concern is the hammer not staying solidly in full cock position. Out of the stock it seems to hold fine. By my eye the sear appears to be all there and the end isn't chipped or missing.
I'm hoping someone has some adjustment setting ideas that may help.

There are a couple of items to consider with respect to the full cock issues. Some of the will relate to the lock, specifically the tumbler. With the lock removed from the rifle, does the lock hold steady in full cock? If it does hold firmly in place when the lock is removed, then the issue is related to the depth of the trigger inlet. If the hammer falls from full cock with a bit of pressure then the tumbler needs some investigation. You have checked the lock when it is out of the stock and it appears to be fine and the triggers will need the trigger plate to be shimmed further out.

 

[rafterob]

Yes, in this case deforming the underlug is the best method to tighten up the wedge keys. Shimming the barrel is not a good idea. Others have mentioned already that shimming the trigger bar is one immediate fix to the hammer/trigger set positions. One other issue you mention is having to push your front trigger forward to enable it to set. That notch on the front trigger is very small and on mine I could not get it to stay set because it was too worn. I ended up buying a new double trigger from Deer Creek. Also take the lock out and make sure the hammer will stay in the full cock and half cock position. Make sure the "fly" is in place and moves freely.

 

[renegadehunter]

MO E W, thanks for the pictures. My return spring isn't in that position at all, so I will adjust it. I also like the idea of the flat head screw, that would really work well for adjustability. Last night I shimmed the trigger assembly out with washers, I had to use two different sizes and drill out the front one a bit so that bigger bolt that goes clear through from the tang would fit through it. It fixed the hammer issue, it holds strongly now and I can't push it with enough force to get it to release now. But now I can't get the set trigger to function at all. I now know the return spring isn't in the correct spot, but also think I may have shimmed it out too far. I will try the flat head screw idea tonight so I can more easily adjust how far out it sits.

 

[renegadehunter]

rafterob, I'm curious as to why shimming the barrel isn't a good idea?
I know that bending the wedge pins won't work, I already tried that and they have to have so much bend in them to get a tight fit that they come up against the escutcheon on the other side and would result in bending the heck out of them if I forced them through.
I have read about tapping the underlug closed a bit and can try that, but still curious why shimming the stock isn't a good idea.

 

[MO_E_W]

The tighter the whole barrel is to the wood the less vibration you get when rifle is fired. Vibration will cause inaccurate shot placement.
That is why some modern rifles have their barrels bedded in.
Try pinching in of the barrel lugs. Tap in the middle of the lugs (careful these are soft) a little bit at a time.
That will narrow the slot for the wedges to go into. Making things tighter.

On the trigger assembly, the flathead screw works for the front. You may need to shim up the rear of the trigger also. To allow clearance
of the trigger to the sear engagement.

MO

 

[ohio ramrod]

Don't listen to the people who tell you how to fix it !It is a dangerous bomb waiting to go off! Ship it to me for proper disposal.And your family will be safe!

 

[rafterob]

The other thing to consider for the barrel wedges is to "capture" them. Honestly this is the best option in the long run. I have been intending to do this on mine for over a year now. Just have to act on it. The good thing about the Mountain rifle is it has two wedges. I lost the single wedge on my traditions Hawken while on a woods walk. I have lost two wedges (not at the same time) from my Mountain rifle over the years.

 

[renegadehunter]

The tighter the whole barrel is to the wood the less vibration you get when rifle is fired. Vibration will cause inaccurate shot placement.
That is why some modern rifles have their barrels bedded in.
Try pinching in of the barrel lugs. Tap in the middle of the lugs (careful these are soft) a little bit at a time.
That will narrow the slot for the wedges to go into. Making things tighter.

On the trigger assembly, the flathead screw works for the front. You may need to shim up the rear of the trigger also. To allow clearance
of the trigger to the sear engagement.

MO

Thanks MO_E_W.
I did also shim the rear with a washer. I'm wondering if it was too much, as the set trigger now won't even begin to try to function. Before I shimmed the front and back out the set trigger would set and hold on it's own about 50% of the time and would work 100% of the time if I pushed the front trigger forward slightly (but I had the unsafe condition of the hammer releasing with moderate pressure applied to it). Now, while the hammer is holding very well, the set trigger won't ever catch unless I push the front trigger forward firmly and as soon as I release the forward pressure on the front trigger it trips the hammer down. It would be safe and useable right now as is if I simply ignored the set trigger and just used the front trigger on its own, but I'd of course like to try to get the set trigger working too.
My plan right now is to remove the trigger assembly again, adjust the return spring to the correct position, add the flat head screw to the front for an adjustable shim, and completely remove the shim from the back to see what I get.

 

[renegadehunter]

Don't listen to the people who tell you how to fix it !It is a dangerous bomb waiting to go off! Ship it to me for proper disposal.And your family will be safe!

Such a reasonable offer Ohio! But fat chance. ha ha

 

[Professor flintlock]

Such a reasonable offer Ohio! But fat chance. ha ha

Might be a reason it was hanging on the wall.

 

[rafterob]

It helps to do some actual measuring to determine how much shim you need. I have never heard of anyone needing to shim the back (before this post) and in my case that screw would be way too much of a shim. Mine required less than half the thickness of a popsicle stick (which is what I used). AT full cock measure the distance from the sear to the front inlet. Then deduct the height from the bottom of the trigger bar to the top of the trigger bar when in the set position. That would be how much shim you need.