Small gap between lock and barrel

[bads1buell]

I have a rifle that has a small gap between the lock plate and the barrel. Shot it for the first time yesterday and noticed some fouling on the back side of the lock while cleaning. Is there anyway to close it up so it's tight against the barrel? Lock is a large Siler.

 

[necchi]

Flint or Percussion?

 

[bads1buell]

Flint
http://s515.photobucket.com/user/bads1buell/slideshow/Smoothbore

 

[b737tvc]

First I would check to see if the bolster is seated correctly, if not take a little wood down that the lock plate is sitting on, if bolster is to thick carefully shave it down. Just a thought..


Beaver T.

 

[geb324]

Try to tighten the lock bolts if that doesn't work
you need to inlet the lock a bit more. Powder can build up behind the lock plate and cause a potential bang you don't want.

 

[bads1buell]

I tried to tighten it up a bit more however, it still has a small gap.

 

[bads1buell]

How should I check to see if the bolster is seated correctly?

 

[Col. Batguano]

You shouldn't be able to slide a knife or razor blade in to the gap when it's all tightened down. First try inletting the lock plate a little deeper. If, when it's all re-inletted to your satisfaction given the outside stock dimensions of the lock panels, and where the tails of the lock sit, you have a gap on one edge but not the other then file the tight edge of the lock bolster to make it sit more flush. True the whole thing up with a stone when you're done to make sure it's flat.

Last resort is a strip of something like very thin leather between the bolster and the barrel flat to make an o-ring seal. Those can fail though. Remember the Challenger?

 

[necchi]

Inletting black,, or soot from a candle.

clean/dry lock plate. Hold the lock over a candle to pick up some soot on the inside perimeter of the lock plate.
(I use an oil lamp with the wick turned high)
Carefully place the lock back in and press it or install the screw snuggly.
Remove the lock plate and inspect where the soot covered metal is/has made contact.
High and low points will be revealed.

That way you'll know if it's the wood or bolster that needs material removed

 

[b737tvc]

take some inletting black and put a fine coat on the bolster then carefully put lock back into place. Tighten lock screw to its normal tightness then back it off and pull plate off. If black is on bbl you know its seated on the bbl, then its a level issue.

Beaver T.

 

[Ken Cormier]

ff Just a quick :surrender: question what are you calling a bolster on a flintlock. I though that a bolster was where the nipple screwed into. I don't know for sure as I only own flintlocks. Or am I just dumber that my kids think.

 

[Col. Batguano]

I'll only answer the first question, and let your kids answer the second. :idunno:

The bolster is the thicker piece of metal on the inside of the lock plate that the pan is attached to, and the main spring hooks in to. On most guns it's about 3/16" thick, and is the only lock metal that contacts the barrel flat.

 

[necchi]

"U"

It is tuff, folks call different parts different things, the same thing can be referred too with many names and parts are called different names even in different parts of the country :idunno:

 

[bads1buell]

Just measured gap and it measured .008-.010
I was able to get a piece of paper folded in half between the barrel and the lock. Guess I will try the inletting black next. I removed a little wood around the lock and it might have helped it some.

 

[Len Graves]

I think I would try the soot black thing. I would soot the whole inside of the lock and it's internal parts to see if there were anything holding the bolster away from the barrel. I have seen some locks with a brass or steel shim soldered to the bolster to correct this gap. I would not use leather, there is a great deal of heat there from the flash of ignition powder which in time could open ( burn the leather) the gap again. If enough powder were to trickle into that crack and collect it could eventually ignite and blow the lock off the gun. I believe wood removal where the lock plate sets or some internal part sets will correct your problem.

 

[Ken Cormier]

ff Thanks necchi and the Col.Who says that your never to old to learn something new.

 

[54ball]

. I removed a little wood around the lock and it might have helped it some.

Ok, removing wood from around the lock will accomplish nothing but make the panel look bad.

The trick is to remove wood and sometimes metal from under not around the lock.

First you have to find where and what is keeping the lock from mating with the barrel.

The first place to check is the spring and the guts. When you take the lock out look for any shiny areas where the parts have mashed or burnished the wood.

I cant stress how delicate and precise this operation is. We are talking about just a tiny little bit of material.

Secondly and most important it has to go down square in relation to the barrel. If it is canted one way or another, removal of wood in the wrong place may exacerbate the problem. Remember you can always remove material but it is pretty hard to add it.

For instance, lets say the culprit is at the topside of the lock, removing wood at the bottom side will only widen the gap and make it even more crooked.
I use candle soot from a burning candle. I just hold the part over close or in the flame, whatever soots it up best. Dome use sharpie markers or even lipstick.
Remember what I said about whats under the lock not around it. You do not want to widen the gap between the metal and wood that's around the lock.
So you have to pay real close attention to understand just what the inlet marks are telling you.
A small chisel, emery finger nail file stick, exacto blade or even a properly shaped sharpened nail can be used to remove the colored imprints. Delicately scrape them away.
Once that's removed mark and repeat. Since you have so little to remove I would screw the lock down each time to make the imprint. It needs to be tight like you normally would install it but not "Hillbilly Tight" as that could warp the plate.

When all else fails...You can always apply a small bead of automotive high temp Black RTV gasket to the bolster. Wipe away the excess and it's pretty much invisible. That will at least keep you from blowing the lock off.

 

[Zonie]

Often on factory made guns they coat the lock mortise with their varnish.

While this is nice from a protection standpoint, it often ends up coating the wood which the lock rests on. This will move the lock out away from the barrel.

Remove the lock and notice all of the small surfaces that the lock plate would rest on.

If these are covered with stock finish, use a sharp knife point to scrape it away.
After all of the little surfaces have been scraped, retry the lock.
I'm betting it comes much closer to the barrel.

If it doesn't, you can remove a small bit of wood by continuing your scraping. Sooner or later, the removed wood will allow the lock to fit snugly against the side of the barrel.

 

[necchi]

If these are covered with stock finish, use a sharp knife point to scrape it away.

Just a tip;
I found if I put the small common Xacto knife blade in upside down (pointy side in the collar) the bottom of the blade makes a darn good scraper.
Good for the kitchen table craftsmen,
Readily available, cheap and no need to custom make a tool.

 

[LRB]

Any type of shim between the barrel flat and the bolster will cause another gap between the frizzen and barrel flat. Not a danger, but will allow easy water intrusion, or you may lose some of the prime if carried primed for a length of time.