Father tries to help, ends up gouging threads on reciver....

[Captlink]

Hobbing is not done before the threads are cut. I think you misinterpreted what I said. Thread milling is a CNC operation, and before they used CNC equipment, they used a hob mill. A hob mill works the same way, only mechanical.

I used a gear hobber as a apprentice machinist but have never seen them used for threading.I know how bad threading can be no matter how they are formed and a truing operation is SOP in my experience.I hope the op can have the problem repaired in a cost effective way.

[Berniep]

It was a suggestion for the best way.Many times a receiver is threaded with a tap at the factory and is not true.No matter how you do it the barrel should be checked for head-space after barrel installation.Find a general machine shop if you go with a tap it's a minor job and if the guy is nice he may do it for beer money.

Setting up to "clean" ID threads with a single point bit in a lathe would be a nightmare seems to me.

[stangfish]

Not so bad. Just takes time good lighting maybe a mirror and some layout dye.

[Captlink]

Setting up to "clean" ID threads with a single point bit in a lathe would be a nightmare seems to me.

Experience makes it easy in as something as large as a receiver try resetting a bit inside .375 hole threaded 40tpi double. High magnification eye lopes help.

[sinman]

Setting up to "clean" ID threads with a single point bit in a lathe would be a nightmare seems to me.

I could do it in my sleep....well almost in my sleep. Having the right equipment helps.

[thomae]

I could do it in my sleep....well almost in my sleep. Having the right equipment helps.

Stop bragging! Some of us have heavy metalworking equipment envy!

[stangfish]

If you set up your compound right it is a piece of cake like sin said. If you have a left hand threading boring bar you can turn you chuck backwards and cut from in to out and see everything.