This an example of an easy task that someone is going to mess up by welding.
After you weld up this locking bolt you have to mill it or file it down to the correct angle (and it is a small angle) to have it to fit into the rear lump at the proper angle as it was originally made. Of course you will have to do that even if you build up the surface of the locking bolt as I do and for that matter others who do the same. Most welders (that does not include expert micro TiG and lazer welder), cannot weld up the surface area of a locking bolt without having the filler metal flow over into the edges of the locking bolt--thereby spoiling the work of the task at hand.
Typically it is found that the inside width of the locking bolt that has worn away (on English guns) is about .375" wide. Therefore I mount the locking bolt in a table vise on a vertical mill and cut a halfmoon size area away from the forward area of the worn portion of the locking bolt. (it should be noted that both the rear lump and the locking bolt surface had likely worn somewhat, but the locking bolt is easier to built up the surface than the lump). I usually cut the half moon size slot about .035" deep. Then insert a half moon shaped disc of mild steel into the cut away slot an silver braze that in place. If you do this task properly, it is difficult to detect where the metal of the original locking bolt and the added disc meet, and both pieces of metal have the same hardness.
Then with a no. 2 or 3 Swiss pattern or American fine pattern file with safe edges I shape the newly added disc of mild steel to the right angle and gently fit it to the rear lump.
Last edited by bushveld; 04/10/17 03:25 PM.