Russ Hamm lock replacement

[adkmountainken]

i recently picked up a Bedford County style percussion rifle with a Russ Hamm lock.  the rifle shoots great when the lock does its part which is about 50/50..... set trigger works fine one minute then does not engage for a few shots.  caps go off most of the time the nothing and it is not the caps they are good. looked around and it a L&R lock is supposed to fit as a replacement but when looking at pictures and comparing the locks i dont know how that can be they are different design Hamm lock much more skinny.  i took it all apart cleaned and reassembled worked fine for awhile then right back to same problems.

[okawbow]

https://www.trackofthewolf.com/Categories/PartDetail.aspx/777/1/LOCK-LR-BED-P

Take a look at this one.

[mountainman70]

Hey Ken; have you tried to function the lock with NO lock screw in place,just holding it in with your hands?
Reason I ask this is it looks to me like the lock screw hole in plate is awfully close to interfering with the mainspring and sear..
The lock screw is normally on the top bolster behind the cock,toward the rear.Would be interested to see pic of rifle and back side.
The Russ Hamm percussion locks are pretty good unless the mainspring gives it up, the flinters same and frizzen wear out.
i've seen and repaired a few l/rs with the lock screw in wrong place.Some of which probably never fired a shot.
I hope this helps.
Best regards, Dave F

[Scota4570]

 I have never seen that.  Yikes....why would anyone put the lock screw there?

[mountainman70]

No tellin bro. I've scratched my head a plenty thinkin the same thing.
If it turns out to be the problem, I would,if possible, plug the hole in the wood and plate, and lay out a correct position. Might have to drill through the breech plug, or notch it, and no telling about the side plate.
Thars why I would like to see pics.
The old timers had some boo boos and creative ways to fix, same with these contemporaries.
Lord knows I been guilty of creative engineering.lol
Dave F

[adkmountainken]

will get some more pics up shortly!

[adkmountainken]

i should add i was using 60 grains FFF and a .445 rb every shot would blow back the hammer to full cock.

[adkmountainken]

lock screw actually sticks out a bit on front of the lock depending on how hard i tighten it.  it does not seem to interfere though to me.

[mountainman70]

Just looked at this rifle on Contemporary collecting.
Odd side plate,and it sorta looks like a 70s kit gun.Your ball/powder combination should be ok,the blowing back of the hammer sounds like weak main spring.
Your angst with the triggers could be them dragging on the wood inside the inlet.
This can drive a temperate person to the Jug.
Sometimes on Bedford style builds,the barrel appears to be pinned through the inlays,in reality,the lock screw and tang screw are removed and the barrel tapped? forward about 1/4 " to clear the hook underlug from the pin,and barrel slides out the front end.
It may be straight pinned through inlays on this. Just a bit of hard earned knowledge to offer.
Have a great evening. DaveF

[smylee grouch]

Weak main spring yes and sometimes a burned out nipple will let too much gas blow back to cock the hammer.

[Bob Roller]

The odd screw installation looks as if it can stop the mainspring as it pushes the tumbler to fire the gun.The blow back can be because the tumbler has a "free travel"area away from the mainspring.Relocating the cross screw is a good idea.
Bob Roller

[Apple]

I have the same lock and some of the same problems. I could never find a suitable replacement and I liked the way it looked.  I "improved" the strength of the mainspring by jamming a thin piece of metal in the bend of the spring which helped it to reliably set off caps. This lasted a few years until the spring broke. I recently sent it off to Brad Emig who replaced the spring and reworked the internals a bit. He said he "had her running like a Swiss watch" Don't know whether I paid to polish a #$@* but it does work better than it ever has.

[smylee grouch]

Apple has a good idea, send it off to the lock doctor at Cabin Creek.

[Bob Roller]

Too many locks are being ASSEMBLED by people who have little or no idea as to the proper function of anything and the Bedford lock is an odd  one because of a very limited space in the plate for a good mechanism.I made a few for a man in Virginia in the 1960's and that was IT.
W.G.Sutter specialized in them and did a good job and made them in flint as well as percussion.
Bob Roller

[Hungry Horse]

Something not touched on is the lock bolt protruding out of the plate. This lock has a very narrow plate that would be easily bent under the pressure of an over tightened lock bolt. The lock bolt is in a place where it would be most likely to distort the plate if overtightend. I have a Siler that somebody did the same lock bolt positioning to. The Siler is a much stiffer plate, and the lock bolt position is higher, but the flexing of the plate is still obvious.
 I think this half baked idea comes from several kit gun on the market, and builders that never saw an original muzzleloader.

Hungry Horse

[kutter]

What's that small screw for in the tumbler. Just visible in back of the curved cut out of the bridle.
Sear adjustment or something.
Maybe that has something to do with slowing the hammer swing down.

Also, to check and see if the oddly placed Side Lock Screw is hampering to lock,
Place the lock back in the rifle and leave the Side Lock Screw out all together.
Hold the Lock in place with a simple clamp with padded feet to protect the wood and lock plate.
Clamping the lock in going around the bottom of the stock is easier to do than over the top generally.

Test fire with some caps and see if ignition improves.

[taterbug]

I think that screw in the tumbler was for adjusting sear engagement.  Able to make for lighter trigger, but also made the tumbler prone to breaking at the screw hole.  Common on CVAs at the time too, and some others. 

[Bob Roller]

these locks like the others Hamm made were NOT aimed at the very narrow market for better quality.but only met a price.
Several of my German customers could not understand why anyone would even offer such poor quality and my reply was
that on American guns,the lock had to be the cheapest thing among the components used to make it.
Bob Roller

[Rawhide Rick]

Just looked at this rifle on Contemporary collecting.
Odd side plate,and it sorta looks like a 70s kit gun.Your ball/powder combination should be ok,the blowing back of the hammer sounds like weak main spring.
Your angst with the triggers could be them dragging on the wood inside the inlet.
This can drive a temperate person to the Jug.
Sometimes on Bedford style builds,the barrel appears to be pinned through the inlays,in reality,the lock screw and tang screw are removed and the barrel tapped? forward about 1/4 " to clear the hook underlug from the pin,and barrel slides out the front end.
It may be straight pinned through inlays on this. Just a bit of hard earned knowledge to offer.
Have a great evening. DaveF

Well, he’s already intemperate (I think that’s a word) and not shy around the jug.

But you boys are fixin to get me another project on my bench and I have too many there already.

[Rawhide Rick]

The gun ended up on my bench.  Took the lock out and apart today.  I believe Mr Roller hit the nail on the head with regard to the set screw in the tumbler.  It appears to be there to limit the tumbler travel, thereby keeping the spring from smacking the lock bolt.  It was out of adjustment, to the point that when the lock bolt was removed, the tension was released from the spring and it fell off the lock when I took the lock out.  This is an interesting setup.

[Bob Roller]

The gun ended up on my bench.  Took the lock out and apart today.  I believe Mr Roller hit the nail on the head with regard to the set screw in the tumbler.  It appears to be there to limit the tumbler travel, thereby keeping the spring from smacking the lock bolt.  It was out of adjustment, to the point that when the lock bolt was removed, the tension was released from the spring and it fell off the lock when I took the lock out.  This is an interesting setup.

Interesting junk.If the L&R version will cover this lock inlet then get one.
Bob Roller

[Hungry Horse]

 It appears from your photos that the lock mortises are greatly oversized, that makes it easy to put virtually any lock that is long enough to cover the old mortis. Many Bedford gunmakers used standard shaped locks at one time or another. If you want to retain the Bedford style lock plate, I would try to find internal works from a lock of good quality that you can adapt to your existing plate. First choice for me would be a Siler either large or small.

Hungry Horse