Hammer slipping off full cock

[kmolett]

So with a week to go to the hunt I got out my rifle and decided to fix an issue it has been having. It was swelling with the humid weather and it was causing the hammer to fall in half and full cock without the trigger being pulled. I pulled the trigger and removed a bit of wood and for a few days the problem was solved.

So today I took the rifle and moved it to the half cock. It sits solidly in the half cock with no problem. I pulled it to full cock and it was fine. I repeated the process and the second time the hammer fell as soon as I heard it click to full cock.

I tightened all the screws and oiled it and made sure there were not any obstructions, but on the second or third time of bringing it to full cock the hammer fell again.

The lock is an L&R Queen Anne. I am thinking new tumbler as the full cock notch may have broken. With the smallest of pressure I can move the cock/hammer with my hand and it slips the notch.

Any thoughts?

 

[kmolett]

More rambling thoughts as I sit here and ponder my predicament. The wood removal seems to have fixed the half cock problem I had at the first of my post. I also checked to make sure that swelling wood was not pushing on the rear bridle screw causing the sear to swing without the searspring pushing it into half cock.

The full cock problem is happening with the lock removed completely from the rifle.

 

[Bill Hall]

A few things come to mind. Your fullcock notch may be rounded off, just from wear. I've never seen and L and R lock do that, but it's possible. You may need a magnifying glass to actually see it. The notch should have a fairly sharp corner, and basically 90 degrees to the sear nose. If that corner is worn, it will cause a problem just as you described. Touchy little area so best to either take it to a gunsmith, or get a replacement tumbler.

Or, the sear screw could be too tight, which will hamper the sear engagement into the fullcock notch. All the sear screws on the L and R locks I've seen get tight before the sear gets pinched, but again, it's possible, and an easy thing to check. You might loosen that screw a touch and try the lock in fullcock while it's out of the gun.

The sear spring could have weakened, causing the sear to not fully pop up into the notch. Check this by holding the cock past fullcock position, push the sear bar down hard, release your hold on the cock, then check to see if you can get the cock to fall like before. You're trying to manually push that sear nose into the notch. If it won't fall, then your sear spring is too weak, or it still could be that the sear screw is pinching the sear.

Just a few things to check. Can't think of anything more, perhaps others will help. Good luck. Bill

 

[Birddog6]

Check the lock OUT of the rifle. If it works out of the rifle, there is nothing wrong with the lock.
At that point the problem/issue lies IN the stock.

If the lock will not work properly removed from the rifle, then you have a lock issue.

Keith Lisle

 

[matt denison]

"I tightened all the screws ..."

That could be the problem. Try loosening the screw that goes through the sear 1/4 turn. You may be binding it if the screw is too tight.

 

[Loyalist Dave]

The full cock problem is happening with the lock removed completely from the rifle.

In addition to what Bill suggested.., the notch becoming worn, the sear screw and sear spring..., check the tip of the sear itself, aka the "nose". It is much more likely that the nose became worn or broke off a tiny bit, than the tumbler (which is usually quite hard) broke at the notch. A 1/32 or 1/16 chip off the sear can create a world of problems. IF it is that..., you can fix it with a hand file, BUT..., it's very tricky and a lot simpler and reliable to replace that part.

LD

 

[kmolett]

I did check the lock out of the stock of the rifle. I did loosen and tighten the bolts to see if it was binding up the tumbler or the sear arm. None of that worked.

I took and held the sear down and it stayed in place while I put pressure on the hammer. Could it be something as simple as a sear spring? :shocked2: Is there a way to re-temper that spring or should I just get a new one?

 

[Robby]

Kmolett, I have had this problem occur twice. The first time it turned out to be very simple. There was an almost microscopic amount of crud that had compacted in the full cock notch. I took an ice pick and cleaned it out, problem solved. The second time I had to take a honing stone and carefully square up the notch. I probably took apart and put together that lock a half dozen times before I was satisfied, but it still works like a champ. If that's it, go slow and be patient. Good luck.

 

[kmolett]

It appears that the sear spring is the culprit. I held the sear lever down so that it was fully engaged in the full cock notch and then I tried to move the hammer of the lock and it didn't move. Seems that Snowdragon hit the nail on the head. Now I just need to see if I should re-temper the spring or buy a new one.

 

[LRB]

A properly angled engagement with sear and tumbler notch, once manually set, should not slip even without a sear spring at all. The spring is not your problem. It's only real job is to put the sear to it's positions when the lock is cycled. It is not meant to be the primary reason the sear stays in place.

 

[Bill Hall]

Agreed, once the sear nose is in place, the sear spring's job is over. But I'm wondering if there is a sear spring issue that is causing the sear to not get up into the notch all the way to begin with.

It would appear that we've narrowed the problem down to the sear not engaging high enough into the notch, now we just got to figure out why it's not popping in there. Along with a weak spring, it could be anything that is inhibiting the sear's travel. Like already mentioned, a small speck of crud, a little unseen rust, maybe the spring is not seated correctly.

Kmolett, if you haven't already, you might take the lock apart, or just the spring and sear, and scrub that area with a toothbrush and wd-40 (or your favorite solvent). Clean out that little ditch that holds the spring in place. Look for rust or rough spots in the plate, sear, and back of the bridle that might cause drag on the sear. Any rough spots can be polished by sanding with fine sandpaper. As you're putting the parts together, work the sear with your fingers to see if you can feel any rough spot.

If the problem still exists after all that, I'm thinking it must be a faulty sear spring. Wick would be the man to ask about re-tempering. I re-tempered one once over my kitchen stove, but I just got lucky. Good luck.

 

[kmolett]

Wick,

You are right. I shouldn't just be the spring that holds it in there. I took the fly out thinking that might be messing with the notch and all that did was make it slip out of full cock and into half cock. I think I will order a tumbler and a sear to cover all my bases and hopefully that will get me back in business. If not I have a Lyman great plains (Caplock ) that I could use, or go with the Brown Bess Musketoon. I really want a deer with a flintlock so I hope the parts work and that I don't have to use the caplock or smoothbore flintlock. Maybe one day I will take something with the smoothbore, but I would need a lot of time at the range to be comfortable and make an ethical shot.

 

[kmolett]

I did take the whole lock apart as well and gave it a thorough scrubbing and put it back together. I will post my results when I get parts. I put in an order with Muzzleloader Builder Supply so I should get the parts on Wed. They are just a state away from me.

Oh, and I did ask for a new sear spring. $3.00 and I won't burn the apartment down trying to re-temper the spring. I did re-temper a mainspring once in the public BBQ, but after the looks I got from the neighbors I won't try that again. :shocked2:

 

[crockett]

You mentioned a fly. Do you have a set trigger and is it properly adjusted? What I would do is remove the lock and test it outside the stock- if the hammer is staying at full cock even if you hit it then it may very well be something related to the wood in the area or the set triggers.

 

[kmolett]

No I don't have a set trigger on this rifle.