Locating place to drill hole.

[jondar]

I ran a search on this but couldn't find anything. After shortening a shotgun barrell how do gunsmiths locate the exact place to drill the hole to tap for the front sight? Three or four years ago I built a .50 cal model of a War of 1812 Naval cannon, and in drilling the touch hole ran into trouble. I thought I could do it "by eye" and now if you don't look too hard it passes but I can tell it's a fraction of a mm off. Are there tools available for this?

 

[kimbernut]

Brownells

Brownells makes and sells a dandy tool just for this purpose. It's one that you'll look at and say "I could have made that" but it's relatively inexpensive and does a great job.

 

[jondar]

Thanks, I'll give Brownells a call. They surely will know what I'm talking about.

 

[Alvin in AZ]

Is there a snowball's chance I could talk you into -not- installing a bead?

Alvin in AZ

 

[Mac's]

Whenever I trim a shotgun barrel down, I mark the sight line before cutting. First, I Chem-Dye the approximate area of the the new site and then place a section of angle Aluminum alongside the old site. Press it against the barrel and mark a line in the Chem-Dye. The move it to the other side of the barrel and do it again.
The channel angle in the Aluminum automatically centers the barrel and the old front site gives it the proper alignment.
The two lines should be exactly the same distance apart as the old front site is wide. Center punch between the two lines, drill it and tap it. If the old front site was properly centered and if you held the Aluminum snug or clamped it, the new site hole will be centered and exactly in line with the old one. Keep yer powder dry, Mac.
Tuff-Gun Finishes. The Name Says It All
Mac's Shootin' Irons
http://www.shootiniron.com

 

[rustymaggot]

maybe ballance a mini level on the barrel while its in a vice, then mark it.

or glue a bb on first and then determine if its in the right place, snap off the glued bead and drill the glue mark.