Redrilling the Rear Lock Bolt

[Bill-52]

I intentionally drilled & tapped the rear lock bolt at a slight angle to accommodate pre-drilled holes in the sideplate.  Now that I'm about to bring down the side and lock panels to their final width across I realize the rules of unintended consequences also apply to gun building.

In order to straighten the rear lock bolt, I'll have to drill and tap a new hole in the lock plate which will likely overlap the old hole.  I assume this will require welding the old hole closed??  If the holes do not overlap, can a 10-32 section of bolt be soldered in place? Or would this impair the lock plate's structural integrity?

What about the hole through the barrel tang lug?  I've already drilled that slightly larger for easy clearance.  It will likely just have to be widened a bit further.  Is there a limit in terms of how large (within reason) this hole can be?  If its necessary to reposition, should this hole be similarly welded closed and redrilled?

I'll deal with the side plate as I should have done originally -- shorten it and drill a new front lock bolt hole.  This will allow both bolts to be perpendicular to the plates.

Thanks for any advice, comments or suggestions.  I'm really out of my element when it comes to this type of metal work.

Bill

[Pete G.]

I think that I would just plug the hole with the stub of a screw and re drill. Cut the screw off a little above the surface of the lock plate and solder in place. Then give the stub a few good whacks to make sure it is expanded to completely fill the hole, and dress off flush with the bolster.  Welding up a small hole can be almost impossible. The clearance hole through the breech plug is not critical, adjust as necessary. One trick you might want to try is to tap from the plate side with the lock on the gun. The tap will align with the hole and any angle for a perfect fit.

[eagle24]

I like the idea of filling with a stub of screw soldered in place, although I did weld mine up and redrill on a rifle I finished a few months back.  My situation was a little different though, I broke a HSS tap off in the hole and had no other choice after I mangled the hole getting it out.  I will say that welding it up was not a big issue though.  It took me about 2 minutes to weld it up and about an hour to file/dress the weld back down.  Then I annealed it and redrilled and tapped.  You would still have this option if the screw stub/solder doesn't work out so if it were me, I would try that first.  My biggest concern was what the metal composition of the lockplate was and how it was going to take to welding.  Mine was a Chambers Late Ketland and it welded nicely.  Other lock brands might be different and not weld too good.

[bob in the woods]

What Pete said. I've done it more than a few times when trying to "fix" other folks guns.

[Mike Brooks]

can a 10-32 section of bolt be soldered in place?

Yup, done it myself a few times. You might go with an 8X32 for your new lock screw.

[ramserl]

If you can find some one with a tig setup for welding I would weld up the plate.  It would take less than 5 min. to weld and the same time to clean the weld up (gota love tig welding).  But if not maybe the other way is better.

[horsetrader]

Both will work - Personally I would tig weld! using a treaded rod will work but for me it always feels I have a repair....

[Bill-52]

Thanks, all, for your guidance and suggestions. I'll fix this once I have the side panel down to its final level.  I'll try the soldered 10-32 bolt section first and if that's not working then go with the weld.  Its a small Siler so the metal composition should be okay.  And using an 8-32 will give me a little more room to work with.  I may end up making my own side plate to get the spacing I want -- should have thought of that originally.

Bill

[keweenaw]

Don't bother with the solder.  Just cut the stub you want to put in with a die and thread it all the way through and reef it in place with your vice grips.  The lead on the die will allow you to tighten it better than the solder.  Peen the end on the outside of the plate to completely remove the thread line.  Ditto on the inside.  When you're done it will be invisible on both sides and if your new hole is off by 1/4 diameter, the plug will never come out.

Tom

[Bill-52]

Tom: 

Sorry, I'm showing my ignorance -- "reef it in place with your vice grips."

Thanks, Bill

[keweenaw]

If you cut the threads on a soft piece of steel with a die, the area where the threads are first being cut will be tapered out to the diameter of the shaft.  You want to put your vice grips on the shaft and turn it in very tightly so that the tapered area forms into the threads in the hole.  You can get it in a lot tighter with the vice grips than you could turning in  a short threaded screw with a screw driver.  This will lock the piece in the hole.  After it's in cut off both ends about 1/32" long and peen them then file it flat.  If you do this carefully the plug will be invisible from both sides of the plate.

[Bill-52]

Got it.  Thanks, Tom.

[Pete G.]

I like the tapered thread idea. One again the sign of an experienced builder is not necessarily not making mistakes, but in recovering from them gracefully.