Tapping barrel for scope mount

[boker]

Hey guys I was wondering of u was going to tap say a cva hawkens barrel for a scope mount , how would u go about it ? How deep would u make your taps ?

 

[roundball]

I'm under the impression that yours is somewhat of a clone of T/C Hawken...and if so, the holes may already be there.
At least on TC Hawken barrels, they are set up to use a flat Weaver style base for scope mounts, using existing holes where the rear sight is located, and a hole at the back end right on top of the breechplug...normally has a dummy screw in it.

 

[ohio ramrod]

Even if your existing holes don't match the weaver mounts it would be easier to make scopoe mounts that fit your holes than tapping a shallow blind hole. :idunno:

 

[Sperit de bois]

I would/have redrill the mount,on modern rifles, not the barrel,less chance to ruin the barrel. Then if /when you remove the mount there arnt "many holes" in the barrel.
Weaver makes a mount that is in two parts so you line up the different parts to what ever holes there are in the barrel and then mount the scope to them,Universal Mounts.

 

[nkbj]

TC made mounts for both their Hawken / Renegade rifles and their New Englander to attach at the rear sight screw holes. Those are real shallow holes so I'd go very very shallow as I could. Matter of fact I'd have someone do it that does it all the time.

 

[Loyalist Dave]

The actual procedure you need a press, to ensure the holes are level with the plane of the barrel flats, and to set the max depth so you don't ruin the barrel. You buy two types of taps, the starting tap (which is what folks usually find at the hardware store) and a "bottoming tap". The second tap is needed as since the depth is shallow the threads are only started, not fully cut. The bottoming tap finishes the thread cutting to the proper depth, but can't be used to start thread cutting.

A professional smith will have all of this, and it's a simple procedure for the smith and should not cost very much. Should take about an hour or less. Also, it's a good idea to be a customer of your local smith for the inexpensive, mundane stuff that any smith can do for you..., keeps them in business for when you need them to do the special stuff. :grin:

LD

 

[jdkerstetter]

....and your local full service smith will insure that the holes are in a straight line and centered on your barrel. This is critical and not as easily achieved as some may think. This is not something you are going to pull off with a hand drill....or your average drill press for that matter.

Last time I checked with a local smith he got $10 per hole. That is money well spent. Trust me.

Enjoy, J.D.

 

[Zonie]

Hey guys I was wondering of u was going to tap say a cva hawkens barrel for a scope mount , how would u go about it ? How deep would u make your taps ?

Measure the wall thickness of your barrel at the muzzle.
Because your CVA has a straight unswamped or untapered barrel this dimension will be the same at the breech.

Subtract 1/16" from the wall thickness. This should be the maximum depth of your tap drill.

As was said you will need a taper tap to start the threads and then you will need a bottoming tap to increase the depth of the threads started with the taper tap to the bottom of the tap drilled hole.

If you have not threaded holes to the bottom, this operation must be done by hand while using a judicial amount of torque on the tap.

Not only are these small taps easy to break with normal tapping but when the bottom of the tap contacts the bottom of the hole any further rotation will instantly brake the tap off in the hole.

Use the special thread cutting oil to lubricate the tap. Regular motor oil, 3 in 1 oil or WD40 won't do the job.

 

[Sinner]

Gotta disagree with Jd on this one.
If you don't have reasonable access to a 'smith, then you can drill the holes with a press and tap by hand. You can set the press to stop at a given hole depth. Just be sure to be judicious in marking the hole locations.

I have seen somewhere some mounts that are shaped to slide down over the barrel and have set screws to hold in place. I know nothing about them, as how secure they are.

 

[jdkerstetter]

Gotta disagree with Jd on this one.
If you don't have reasonable access to a 'smith, then you can drill the holes with a press and tap by hand. You can set the press to stop at a given hole depth. Just be sure to be judicious in marking the hole locations.

Didn't mean to give the impression that it couldn't be done at home but when I said "average drill press" what I was implying is that most drill presses have too much wander to get precise holes. You don't want to use hardware/walmart bits....you want short bits that resist deflection. You are best served with a mill/drill and spotting bits or something simular if you want perfectly alined holes.

Now, if you have a jig it's easier but Midways price for the 4-hole octagon barrel jig is $95...hardly seems worth it for one barrel but your smith probably had one.

I only made a recommendation as I don't know anybody else's skill set. I don't want to mislead a novice into thinking this is as easy as putting the drawer pulls on his kitchen cabinets and make a costly mistake. Utlimately we have to make our own decisions and live with the consequences.

I have seen somewhere some mounts that are shaped to slide down over the barrel and have set screws to hold in place. I know nothing about them, as how secure they are.

Weaver and B-square have made those no-gunsmith scope mounts. Not sure if they currently produce one for ML's.

Enjoy, J.D.

 

[lonecamp]

Just throught this in,a scope i mounted on a T/C senaca. Its mounted off to one side clears the original sight and hammer. Works well for working up loades etc. Use the open sights for hunting.