Musket lock - hammer screw removal

[StuP]

Need some advice please. I need to remove the sear tumbler from a musket lock and I can't shift the large external screw that holds the hammer to the sear tumbler. I tried Kroil, a little heat, freeze off.

One of the challenges is the screw slot is very long but narrow, so I can only get a small screwdriver to fit.

Also locked it all down in a drill press, hand turning a screwdriver bit in the screw sheared the bit easily.

Any other quick tricks of the trade I can try ? It's starting to annoy me, and that's when I usually foul things up !

 

[Horsehat]

If you have a bench grinder, grind a wide screwdriver down to fit the slot. As an alternate to this if you have a price of steel that is 4-5 inches long you can grind one edge, toward the end, to fit the slot, you can get a good bit of leverage this way, just make sure it fits the slot well or you will bugger it up. Definitely soak overnight in Kroil and be patient. A quick hard tap will free a frozen bolt better than steady pressure. Is this an original or reproduction?

 

[Winks]

Do you know for sure if it is left-hand or right-hand threads?

 

[StuP]

It's a repro, and I was wondering about the thread being rh or lh. I have a tumbler on order, I suspect I should be patient and check the thread on that.

I don't have a grinder or spare stock to make a tool, but looks like I may need something ! Just such a narrow slot none my quality hollow ground drivers, (of a decent size), will fit.

Patience, patience......

 

[StuP]

Well, it was a standard rh thread. I ended up using, (and trashing), a chisel pointed divers knife, good thickness, or thinness and right width . I clamped the lock in a machine vice, then used a drill press locked on the top of the knife pommel to stop the blade rising out of the slot while turning the blade with an adjustable wrench, it was TIGHT.

 

[Horsehat]

Glad you got it

 

[cullen1780]

So that's how you were using use the drill press.
Thanks for clearing that up. I'd hate to use an impact driver on a lock.

 

[Winks]

Glad it's out.