CVA trigger/lock problem

[ravenousfishing]

I have a later model CVA mountain hunter rifle that has started giving me a problem. When the set trigger is set and the forward trigger is pulled, the hammer only drops to the half cock position. If the set trigger isnt set, the hammer falls fine. Where should I start looking?

 

[R.M.]

Stuck or missing fly. This has been discussed here many times. If you can figure out how the search feature works, try looking there. Like I said, there should be a ton of info about it.

 

[Zonie]

If you remove the lock from the gun and cock it to the full cock position, look at the area where the half cock notch is cut into the tumbler.

At this notch you should see a small movable little piece of metal that when moved towards the rear of the lock will expose the entire half cock notch. When moved downward towards the front of the lock it will cover up part of the half cock notch. This item is the "fly".

It's job is to get out of the way while the guns hammer is being raised from the fired position so that the pointed nose end of the sear can enter the half cock notch.

As the hammer is raised from half cock to full cock, the nose of the sear jumps over the fly and continues on until it snaps into the full cock notch.

When the set trigger blade hits the sear arm that's sticking out away from the lockplate it knocks the nose of the sear out of the full cock notch releasing the hammer.

As the hammer falls the fly and the half cock notch will be rapidly approaching the nose of the sear and when that nose gets to the fly it is supposed to "jump" over the half cock notch allowing the hammer to continue to fall.

With your gun, for some reason the fly is not blocking off the half cock notch like it should so the sears nose is jamming into the half cock notch.
This by the way is an excellent way to break the sear or the tumbler.

Your task here is to figure out why the fly isn't doing its job.

It might be due to a lack of lubrication.
It might be due to some hardened grease that is keeping the fly from moving
It might be because the screws that hold the bridle or cover over the tumbler are loose.
It might be the fly is worn out or broken off.

Only by looking will you know.

This is the reason I went into some detail about how it is supposed to work.

You should first raise the hammer to full cock.
Then, while supporting it with your thumb, push up on the sear arm to release the tumbler.

SLOWLY allow the hammer to lower, watching the nose of the sear (which will be resting against the tumblers surface. When it gets to the half cock notch it should run into the fly which will rotate a little, blocking off the notch.

If it doesn't you will be able to see the reason why.

 

[ravenousfishing]

Thanks for the reply Zonie. Had pulled the lock before and had tightened the screws and thought everything was working. Just pulled the lock again and resnugged the screws with a little more torque. Seems to be working now. Out of curiosity, why would this only be an issue when the set trigger was set?

 

[krshade]

When you use the trigger 'unset', your finger keeps the trigger blade against the sear bar and holds the sear out of the way. You probably can't release the trigger before the sear is past the half cock notch.
The set trigger has a snapping action and doesn't hold the sear bar, just kind of kicks it.

 

[paulvallandigham]

Before putting that lock back in the stock, Soak the lock in some good Alcohol based cleaner, to get all the Accumulated crud out. Then after it dries, test it carefully for movement, and "FEEL" for any burrs. If they exist, take the lock apart and remove them. Then oil the internal parts of the lock well, with a good oil.

Finally, check that lock mortise for wood chips. Factories are notorious for not cleaning off chips, and burrs in these places. Clean them out, and then give the mortise a good, THIN coating of gunstock oil finish, or any other kind of wood sealer. You want to keep OIL out of the wood itself, which will soften, and WEAKEN, an already weak area of your stock. Finishing and sealing the lock mortise makes it much easier to keep clean, so you don't transfer crud from there to the internal parts of the lock.

Removing the lock, cleaning,( old toothbrush, and soap and water), rinsing( water then alcohol) then re-oiling the parts, and checking the screws for tightness, should be part of the cleaning process you do every time you use the gun. I clean my locks while letting the barrel SET and SOAK with soap and water, to give the soap the chance to do its job.

 

[jessestrish]

You also should check the spring on the triggers that control the tension. It may be loose. Or, if your tang screw is what holds the triggers in place, make sure that they are snuggly positioned in the inlets in the stock created for them to be sure that contact is being made with the sear properly.