CVA Mountain Lock Problem

[wpage]

Hey All,
Looking for some dialog re CVA Mountain rifle lock issues. Driving the question is my cva mountain lock is gone haywire and has become unsafe. It will not lock back correctly. Sometimes it locks back fully, it always locks half cock.
So took a a few images. For clarity, however being novice to how these old fashioned things work. Please share your knowledge.

First image is for visual identity

Second image is exposed lock components

Thanks.

 

[Acorn Mush]

It would help to see a picture of the full-cock notch.

 

[Grenadier1758]

Step 1. Does the lock go to and hold in full cock? If it functions fine outside of the stock, then the lock is not part of the problem.

Step 2. When the lock is in the stock and the triggers are set, does the lock hold in full cock? If yes, then the rear trigger lever is too high. The trigger plate needs to be lowered by using cardboard shims between thr trigger plate and the stock.

Step 3. Are there signs of the sear being pulled into the stock and hanging up to prevent the sear from entering the full cock notch. Some wood may have to be removed. The lock screws may be over tightened and pulling the tip of the sear into the wood.

 

[R Ellis]

Some CVA rifles have the trigger inlet to deep and require shimming

 

[wpage]

So this rifle has sat idle for many years. Was a family hand down legacy. It refuses to lock back fully 99% of the time...

In taking it apart the problem appears to be a cam like washer that blocks the engagement to full cock lock back. Thinking of removing this "cam swinging on a washer" Will post image later.

 

[Notchy Bob]

There is a little swinging device between half-cock and full cock, mounted on the inside of the tumbler. It is really tiny. This is called the “fly” or “detent,” and is necessary for proper function of the lock with double-set triggers. It keeps the sear nose from dropping into half-cock when the hammer falls upon firing. You don’t want to remove it.

Older CVA locks had an adjustment screw in the tumbler to regulate engagement of the sear nose at full cock, to enable adjustment of the weight of the trigger pull. It sounds to me as if this screw may be turned too far out, preventing the sear nose from engaging reliably. If that is the case, you may be able to just turn the screw in a little. I’ll try to post pictures later today if I can get some time.

Deer Creek Products has manuals for all of the old CVA guns. I’m unable to post a link with the device I’m using right now, but if you search for “deer creek products” you should find their website. The link to the manuals is shown on their menu.

Good luck with it!

Notchy Bob

 

[smo]

Here’s a few things too consider…,

Is it loaded?
I’ve bought more than one that was..

Try to loosen the lock mounting screws just a little. Sometimes over tightening them will cause issues with the locks function.

Here’s a new lock and trigger assembly from Deer Creek Products that Notchy Bob mentioned above…( on sale!)

I would disassemble the lock and give it a good cleaning ( watch out for the fly) as mentioned above.
Then reassemble it and see if it functions correctly.

From the CVA manual..

 

[wpage]

Thanks for all the "Pro Tips" Here a few images. Yes the pin points to the 'fly' or cam like thing that prevents the full lock of the action....

 

[rp77469]

Here’s a few things too consider…,

Is it loaded?
I’ve bought more than one that was..

Try to loosen the lock mounting screws just a little. Sometimes over tightening them will cause issues with the locks function.

Here’s a new lock and trigger assembly from Deer Creek Products that Notchy Bob mentioned above…( on sale!)

NOT the MR lock or trigger. This lock has no fly, and might not have a bridle. Not a set trigger either.

 

[Notchy Bob]

Thanks for the photos.

That little screw with the coil spring on it is the sear engagement screw. It’s hard for me to see exactly what’s going on, but it looks like it is backed out enough to not interfere. Hard to say for sure.

I’m not seeing a clear picture of the full cock notch in the tumbler, but my vision is not good. I can tell you, the innards of that lock could benefit from polishing, though. All of those rubbed areas and scratches and rough spots really shouldn’t be there. Smoothing things up, and a good cleaning to remove crud that accumulates over time should help a lot.

If you can, please try to slip the edge of a piece of white paper in between the tumbler and the lock plate, so we can get a better image of the tumbler notches. They are hard to make out against the dark background. If that works, it will be easier than removing the hammer and the tumbler, which you may need to do eventually, anyway, once the problem is diagnosed.

Hang in there, Bud. Some of the CVA Mountain Rifles had some issues, but once the bugs are worked out, they make very nice shootin’ irons.

Notchy Bob

 

[wpage]

Thanks for all that...

Will give those tips ago and get back.

 

[Gtrubicon]

I had issues just like yours with both of my mountain rifles. The 45 cal was fixed by shimming the trigger up out of the mortise so the trigger bar just barely cleared the sear on the lock. The end of the sear was just barely making contact with wood in the inlet, so I trimmed the end of the sear down a bit to clear. That solved the 45.
The 50 was a very used rifle when I got it. It had the same issues. I shimmed the trigger and after dealing with a worn out lock, ordered an L&R RPL percussion lock and installed it on the rifle. It is now my best shooting rifle and works flawlessly.

 

[Grenadier1758]

The Deer Creek parts diagram for the CVA Mountain rifle does not have the drawing for details of the lock. @wpage's rifle has the double set triggers. The fly should not be removed, and it should not be covering the full cock notch, only the half cock notch as the hammer falls from full cock. The fly cannot cover the full cock notch unless the tumbler and bridle are so loose that the fly is out of position off its post. With set triggers, once the hammer is pulled to full cock, the hammer has to be fully lowered and then the hammer can be pulled to half cock. This lock could use a good cleaning of the old dried up oils and greases that have been idle for all those years. Do not lose the fly. Most of the gunk can be cleaned without taking the lock apart by a thorough dowsing of the lock with penetrating oils then lubricated with Birchwood Casey's Barricade. Doing more than removal of the bridle will require a mainspring vise and properly fitting screwdrivers. Make sure the fly is properly positioned on the post in the tumbler. Do all this work with the small parts over a large sheet of paper. Small parts are easily lost.

You will not be able to use the set triggers if the fly is removed.

Reread @Notchy Bob's post.

The Deer Creek manual for the side lock muzzle loader might be helpful in covering details of usage.

 

[Notchy Bob]

I had issues just like yours with both of my mountain rifles. The 45 cal was fixed by shimming the trigger up out of the mortise so the trigger bar just barely cleared the sear on the lock. The end of the sear was just barely making contact with wood in the inlet, so I trimmed the end of the sear down a bit to clear. That solved the 45.
The 50 was a very used rifle when I got it. It had the same issues. I shimmed the trigger and after dealing with a worn out lock, ordered an L&R RPL percussion lock and installed it on the rifle. It is now my best shooting rifle and works flawlessly.

The voice of experience!

Several of the fellows have suggested shimming the “trigger group,” and @Gtrubicon explains why. I would try simple remedies like this first, before doing anything irreversible. I have two CVA Mountain Rifles, a 50 and a .58. Neither had this particular problem, so I didn’t have to shim my triggers, but both had other minor issues that needed fixin’. They are great rifles, once the bugs are cleared out.

One thing I do when disassembling a lock is to put a hand-sized piece of corrugated cardboard on the workbench. I poke holes in it with an awl, and as I remove screws from the lock, I screw them into those holes in the cardboard and label each one. This not only helps prevent losing the screws, but also keeps me from mixing them up.

As noted above, L&R makes a higher-quality replacement lock for this rifle, if the OEM lock issues are unfixable. L&R flint locks frequently need some attention to get them sparking well, but the internal mechanisms of L&R flint and percussion locks are very good.

Notchy Bob

 

[wpage]

Here for a spacer to shim out the trigger.

 

[wpage]

Any tips on re inserting the trigger spring?

I cannot get that bugger leaf spring in...

 

[wpage]

Any tips on re inserting the trigger spring?

I cannot get that bugger leaf spring in...

With help from a friend, vise and vise grips all set...
Now will this washer/shim do the trick!

 

[Notchy Bob]

If I'm interpreting that picture correctly, I'm seeing a washer being used as a shim, but that's not where it was supposed to go.

The "L" shaped part that pivots on a screw is the sear. The sear has a "nose," which engages the notches in the tumbler when the hammer is cocked, and an "arm" projecting outward. When the trigger is pulled, it hits the sear arm to pivot the sear and disengage the sear nose from the tumbler. The triggers are not shown in your photo. This is a sear:



Note the sear arm (left) and sear nose (right).

The part lying loose, below and to the right of the lock in the photo in post #15, is the bridle. I don't see it in the photo, but a little leaf spring should be above the sear. This is the sear spring. I think that may have been incorrectly identified as a "trigger spring" in post #16. So, it looks from the picture as if the washer is going between the sear and the lock plate. I don't think that's going to help.

The triggers are not in your photo.

Before you do any more, please look over this diagram:



That diagram does not show the bridle, which they probably left off so it would not obscure the other moving parts. I think the problem as described in post #1 suggested a poor engagement of the sear nose with the full-cock notch in the tumbler. In looking at the photo in post #15, I get a clearer view, and it does look as if the adjustment screw (that's the screw with the tiny coil spring wrapped around it... see diagram) protrudes too far into the full-cock notch, preventing the sear nose from engaging. I think if you back that screw out a couple of turns it may solve your problem. I might add that CVA and Traditions locks are the only factory locks I know of that have an adjustment screw like that.

The washer, in the position shown in the photo in post #15, will not help, and may even interfere with the function of your lock. If it was put in, it should be taken out.

Please let us know how things are progressing.

Notchy Bob

 

[wpage]

If I'm interpreting that picture correctly, I'm seeing a washer being used as a shim, but that's not where it was supposed to go.

The "L" shaped part that pivots on a screw is the sear. The sear has a "nose," which engages the notches in the tumbler when the hammer is cocked, and an "arm" projecting outward. When the trigger is pulled, it hits the sear arm to pivot the sear and disengage the sear nose from the tumbler. The triggers are not shown in your photo. This is a sear:

View attachment 327596

Note the sear arm (left) and sear nose (right).

The part lying loose, below and to the right of the lock in the photo in post #15, is the bridle. I don't see it in the photo, but a little leaf spring should be above the sear. This is the sear spring. I think that may have been incorrectly identified as a "trigger spring" in post #16. So, it looks from the picture as if the washer is going between the sear and the lock plate. I don't think that's going to help.

The triggers are not in your photo.

Before you do any more, please look over this diagram:

View attachment 327593

That diagram does not show the bridle, which they probably left off so it would not obscure the other moving parts. I think the problem as described in post #1 suggested a poor engagement of the sear nose with the full-cock notch in the tumbler. In looking at the photo in post #15, I get a clearer view, and it does look as if the adjustment screw (that's the screw with the tiny coil spring wrapped around it... see diagram) protrudes too far into the full-cock notch, preventing the sear nose from engaging. I think if you back that screw out a couple of turns it may solve your problem. I might add that CVA and Traditions locks are the only factory locks I know of that have an adjustment screw like that.

The washer, in the position shown in the photo in post #15, will not help, and may even interfere with the function of your lock. If it was put in, it should be taken out.

Please let us know how things are progressing.

Notchy Bob

^^^This helps to understand the nomenclature. Also for my next attempt.

Did go ahead B4 seeing this with my attempt with the washer and it somehow worked. Not 100 percent but enough to make it OK for range work.


Appreciate Bob and others taking time to contribute to making this work. Next time I open this lock up, will remove washer and report back.

 

[Notchy Bob]

Good! I’m glad you got it working.

Regarding that washer, if it’s not too thick, maybe it will help to reduce some friction. There were some rubbed areas on the inside of the lock plate caused by normal movement of the sear, and using a very thin washer as a spacer may help reduce some of the friction that causes that, but you don’t want the spacer to be too thick.

You’ll want to make sure you have good, positive engagement of the sear nose with the notches in the tumbler at half and full cock, for safety, to prevent accidental discharge.

Enjoy your rifle!

Notchy Bob