Cutting barrel breech angle

[RBaker]

Yes, at 35*

Edited meant 25*

 

[Tozguy]

This is a very good video on the subject.

 

[Earl Horgeshimer]

I use a piloted reamer that I got from Dave Kiff at Pacific Tool. A few weeks ago I was chambering a barrel and forgot to cut the cone before I cut the chamber. I did not have anything that I could cut the cone with without rubbing. I called a buddy that is a professional gunsmith and he told me that he used to use a piloted reamer to cut the cone but his reamer got dull and was chattering badly. What he did was to take his Aloris BXA12 tool holder and move the insert as shown in the picture. He said it was so easy that he would never go back to the piloted reamer. Just remember to set the compound to 25 degrees to cut the cone and to set it back to 29 degrees when you are done. (Dont ask me why I included this reminder)

 

[Earl Horgeshimer]

Here are the tools that I made to measure cone depth for all BAT actions
.

I made the fixture out of an old unlimited barrel (1.45 inch diameter) I attached the dial indicator via a set screw. I made the stem and carefully cut the 25 degree angle to match the angle of the cone. I have a short piece of an old barrel showing the chamber. I drop the stem into the chamber and slide the fixture over it. I calibrated the dial indicator to be at zero on a finished barrel. I use this device while the barrel is in the lathe. I use the same device to check the headspace with a go gage while I am reaming the chamber. (to accomplish this feature I had to very carefully take skim cuts off the cone stem until I got the same reading with the stem and the go gage) I cant even guess how much time this device has saved me over the years. Not my idea. I got the idea from my best friend and world class benchrest shooter. Build one. You will love it.

 

[Liljoebrshooter]

This is what they look like
Joe

 

[pontiac428]

Internal chamfer. Basic lathe operation.

 

[Liljoebrshooter]

I use a small CCGT insert boring bar.

Joe