Lock bolts

[OLDSPARKY]

10-32 or 8-32 to hold Siler lock on a Hanies flintlock? Thanks

[rich pierce]

I don’t think anything bigger than a #6 is required structurally, but it looks too small. An 8 is fine for most locks. Huge locks, I go with a 10.

[Daniel Coats]

I used to subscribe to bigger is better but only use 8-32 now days. To be fair I don't build huge guns that would need anything larger

[Bob Roller]

I have made some # 6's and then reduced them to 4x40 or 48 to clear the bend in the mainspring.Also some M4's for the locks sent to Germany..I offered to make these screws but no interest was shown so that is now a dead idea along with the locks.IF you plan to make lock bolts,1018 or drill rod are poor choices. Get 12L14 in the diameter the screw head will be and go from there.!2L has fine machineability and takes good threads,Quality dies are a must..   
Bob Roller

[OLDSPARKY]

Thanks for the help!, usually what dia. do you make the screw head?

[Karl Kunkel]

The first Isaac Haines I built I used an 8-32 for the rear lock bolt, but had to drop to a 6-32 for the front due to ram rod clearance issues.

[B Kauffman]

I use 8/32 for everything.

[bluenoser]

I believe the size and shape of the bolt head would be determined by the style of gun being built.  The bolt head on a Bess would  be a lot different than one on a mid 19th century VA percussion.  Just a random comparison.

[Bob Roller]

Thanks for the help!, usually what dia. do you make the screw head?

Usually the diameter was 5/16 or 3/8 and I slotted them with a modified Woodruff cutter and milling machine or hand slot them with a small hacksaw and then a knife shaped file for authenticity.I haven't made any screws for a long time and used one of the Atlas 618 lathes to make them.Material is 12L14 which IS a steel  FOR screws and little else.I have some,quite a but that is 5/32"diameter for lock internal screws which were mostly 4x40 or 4x48.An alternative screw material can be 1144 "Stressproof"which is also easy to machine and will oil harden.I used it for tumblers and locks that went all over the world and so far no reported failures.Bill Large made gun barrels from 1144 and I would buy short sections that would not make a rifle barrel and make tumblers from it.
Bob Roller

[OLDSPARKY]

Thanks to all!

[Birddog6]

You can also buy blanks from Brownells & cut the threads you want &
the head you want. For a TN they are already squared off heads.

Few years also screws were scarce & made some 6-32 as none were avail. My
procedure is slow, but doesn't matter. I am not in a hurry & only need one now
& then.