6x75 vent liner to 1/4x32

[flatcreek]

Do you think it is possible to just run a 1/4x32 tap in a 6x75 touch hole so I can put a white lighting vent liner in my Lyman Trade rifle?

 

[ZUG]

Here is some information that may help you decide:

6mm = 0.236” - Recommended drill size for a M6 x .75 tap is 5.25mm or 0.206”

Recommended drill size for a ¼”-32 tap is 0.218”.

 

[Scota@4570]

No, do not do that. You will not clean up the old threads completely. The strength will be compromised. You do not want the liner flying out like a bullet. The 5/16 x 32 liner will work. Do not do this kind of drilling and tapping without a rigid setup. Clamp the barrel in place on a drill or mill. Drill the tap hole. Do not break the set up. Use the chuck to guide the tap. That is what the little hole in the square end of the tap is there for.

Do not use a hand drill and tap it free hand.

What is wrong with the factory liner?

https://www.trackofthewolf.com/Categories/PartDetail.aspx/960/1/THL-LYMAN-S

 

[flatcreek]

My calculation show a 6x.75 is 34 tpi and a 1/4x32 is 32 tpi. Distance from thread to thread is .0018 ,less than 2 thousands the extra diameter cutting the threads deeper should more than make that up. I think 1/4x32 will realine the 6x.75 perfectly. Wish me luck I talked myself into it.

 

[flatcreek]

What is wrong with the factory liner?

There junk compared to a white lightning.

 

[ZUG]

Let us know how it works out for you

 

[flatcreek]

Let us know how it works out for you

Think it worked just fine. The 2 thread sizes are so similar, the 1/4 32 just being a little larger so there was no drilling just run the 1/4 32 in and it cut the threads a little deeper.