Problems with a CVA Mountain

[CombatWombat]

I picked up a CVA Mountain in 45 from a deceased estate and it has a couple of issues I can't seem to work out how to fix.

1. She only fires down to half-cock. Gets stuck there, won't slide through to hit the cap.

2. The Set trigger is a total mystery to me. The front trigger fires her ok, the rear appears to be decorative. Can't set it (not even sure how I would do that) and it has no travel when I cock the hammer so it's not doing anything.
If I part-pull the front trigger, I can get the rear one to come forward (it has no spring) such that afterwards I can pull it and it clicks, but cocking the hammer also makes it click and after that it doesn't do anything.

3. Half cock is only about 1/4 inch above hammer-down. Not enough space to put a cap on, as the nipple isn't fully exposed. Is that normal? If not, what would be causing that?

I am entirely missing the mainspring from my trigger, but the front trigger spring is there. Not sure how this could cause these issues, as I've tried holding the rear trigger forward to simulate a spring and it makes no difference.

Not sure if these issues are related?

Inside of the lock. Look ok to you?

https://photos.app.goo.gl/0YykjvJP7NUJqwOB3

[waksupi]

It sounds like a lot of inter related issues. One easy answer, no problem with the half cock. Put on the cap, let down the hammer, bring it back to half cock.

IF it's only going to half cock, DO NOT drop the hammer on it until the fix is found. That's a sure way to break the sear or tumbler.

Without having it in hand, pretty hard to tell you the fix.

[john.k]

Only down to 1/2 cock.........hammer should have a fly ,fly must be free to move..............set trigger not working because spring is broken.......fix/replace spring..................set trigger wont cock,with spring bypassed.....adjustment or worn notch.....but first clean gummy oil and dirt from mechanism. Ditto for hammer fly.

[yeahbub]

CW, I've been shooting/maintaining the CVA Mountain Rifle since the '70's, so I'll tell you my perceptions. It sure looks like someone's been in there and had the lock apart more than once, probably. I don't see the sear drum pivot in the round hole on the bridle, that yoke held on with the three screws. On mine, the sear drum pivot is a solid cylindrical boss that's part of the casting, but it looks like on yours, there's a hole. Is it threaded? Is there a loose screw rattling about in the lock mortise? It appears to be missing, which tells me the opposite pivot which the hammer is screwed to is bearing the whole load. Without support on the inside, the lock geometry is distorted. It really needs that inner pivot, so it looks like you're in the market for a sear drum or a shouldered screw for it, if that's how yours is made. The sear drum is very hard, so drilling a hole and pressing a pin in doesn't seem an option. The trigger bar that engages the sear is 1/8" or so shorter than it should be which would account for the low half-cock position. I can't see the "fly", but a radial wear mark is visible on the lock plate spanning the space between the half-cock and full-cock notches. The fly is necessary to keep the trigger bar from catching on the half-cock notch when the trigger is pulled. The trigger bar is softer than the sear drum, so it's the sacrificial element. From the look of it, you'll need a sear drum (or pivot screw if applicable), fly and trigger bar. Parts are available from Deer Creek Products in Waldron, Indiana, 765 525-6181. They took up production of the Mountain Rifle after CVA quit making them and had rifles, barrels, kits and parts. The Mountain Rifle wasn't a silk purse, but it wasn't a sow's ear either. I've found it to be a very durable factory muzzleloader that's accurate and reliable. Something which may date your rifle is to see whether you have the 2-screw or the earlier 4-screw patch box and round or the earlier hexagonal ramrod thimbles.

[thegatman]

Rebuild the whole lock mechanism. If not buy a whole lock from a reputable dealer and replace it.

[Buckshot Bill]

Here is a photo of a CVA Mountain rifle lock in good working order (although in dire need of a cleaning!)

Photo 1- The green arrow points to the sear drum pivot that yeahbub point out is either missing or damaged
The Red arrow points to the fly that is either missing or damaged, this is why the hammer is dropping to half cock when the trigger is pulled.

Photo 2- Another crummy view of the fly

Photo 3- This screw adjusts the set trigger engagement, if it is threaded in too far the set trigger will not "set". Be sure this screw is not turned in too far. Also the spring would be helpful :)

Hope this helps

[yeahbub]

Great photos, BB! Those tell the story well. You have the same configuration mine has. I can't figure the apparent hole CW's has in the inner sear drum pivot's position. I've never seen that before. Does yours still have the Spanish barrel? I wound up replacing mine with another .50 cal, but 1:56" twist cut rifled for better accuracy at distance. A barrel maker told me the Spanish barrels were button rifled and the deepest that can be achieved that way is .008. He had freshed out a few and said the originals would probably last forever because the buttoning left the surfaces very hard. I'm not sure of the method Deer Creek used when they were producing them, but they were done on Pratt & Whitney rifling machines that were formerly used to make rifle barrels during WW2.

[Buckshot Bill]

Yes mine has the factory barrel, very accurate.