Drill & tap old Huntsman

[AtlLaw]

I'm fixin to try out the old 45 cal, push in breach plug rifle I bought.  Unfortunately it is not drilled and tapped for a scope mount or rear sight.   
 
My old eyes won't let me see the rear sight all that well so I bought one of the Marbles Bullseye rear sights to try out.
 
I'd rather have a receiver sight.  Why didn't they D&T these things?      Has anyone had it done?   

[bikerbeans]

Richard,

I just did a d/t on my tracker II 20 ga for a scope rail and here is what I can tell you.
The factory scope rail holes on the handi barrels I measured are approx. .090" deep
The 20 ga chamber wall on my barrel is about .120" thick, so 0.03" of metal left after the d/t, if you are paying attention.
The CF rifle barrel that I practiced on, piece of barrel from one of my chop jobs, and the 20 ga barrel drill very easily with a high quality bit.
Go really slow unless you like trying to remove broken taps from small holes.  I got lucky and didn't break one on the 20 ga but there is always next time!
IF it where my barrel I would determine the wall thickness where you need to d/t and then make a decision if it is a go or not.  I personally wouldn't d/t a barrel unless all the holes are "blind", not through the barrel wall. 

BB

[PHATINJUN]

I got a couple that I have drilled and tapped no issues. I suspect they were not factory done because most Black Powder seasons in the days they were made would not allow scopes... lots of those old laws have changed in recent yrs. Kurt

[Jim_Ole_Timer]

Curious as to how you do this. How are you able to determine dead top center of the barrel, and how are you drilling the holes, with a drill press or by hand?

[PHATINJUN]

 What I do it is bed the mount to the bbl, then make sure it is square and right down the center with the gun assembled tape it in place then use a transfer punch to mark the holes drill with a press and hand tap. They do make jigs but I have found for me this is what works. Just don't get in a hurry and take your time. Kurt

[bikerbeans]

Curious as to how you do this. How are you able to determine dead top center of the barrel, and how are you drilling the holes, with a drill press or by hand?

I placed the barrel in a vice that I verifed was "level".  I tighten the vice onto the underlug using thin  pieces of wood to protect the underlug and barrel.  I then placed the rail on top the chamber swell and used a small level to get it on TDC.  I held the rail in place with one hand and used some spray paint to spray thought the rail holes and onto the barrel.  You could probably use rubber bands to hold the rail in place instead of your hand.  I don't mind the paint since I normally refinish the metal on all my guns.   Remove the rail, centerpunch the center of each paint mark, chuck it up in the vice on your drill press and go to town.  Set you press drill depth so you don't drill into the chamber.  Take care with the tap operation as it is easy to break one.
 
BB

[quickdtoo]

See DRILLING FOR SCOPE MOUNT in the FAQs. 

Tim

[AtlLaw]

Ah Timmy me lad... You'd think I would know that by now dontcha... 
 
Oh well, I just like to hear myself type!   

[quickdtoo]

Never hurts to ask around, someone will have a way that works for ya, the old skinned cat thing, ya know! 

Tim