Gunsmithing Savage small shank

[Mordamer]

I have the need to make a Savage small shank pre-fit barrel nut barrel. I think I have most of the correct info. Please help with my missing information. I do not have a take off barrel to measure.

Thread spec: 1-1/16x20 3A
Go gauge protrusion: 0.125"
Thread length: ???

I have searched all over and can't find a drawing or spec on the thread length. Customer will be using a standard savage barrel nut.

Thanks

 

[Easy_E]

On mine I thread 1.75 " on the shank . What caliber on bottle neck cartridges the bolt recess plus .010 .

 

[Mordamer]

Caliber will be .223 Ackley improved. 1.75" is long enough while the barrel nut still hides the threads?

 

[Steel head]

I can measure a few of my dead barrels tonight.
1.75 seems about right.

 

[Easy_E]

Caliber will be .223 Ackley improved. 1.75" is long enough while the barrel nut still hides the threads?

With the factory nut yes I have a little more case protrusion with straight wall cartridges and never had an issue .
When turning the blank we turn to the front of the nut diameter and 1.75 is perfect

 

[Steel head]

I’ll be able to post up some numbers in about an hour if that helps.
I have two dead Shilen’s and two factory savage barrels

 

[Mordamer]

I’ll be able to post up some numbers in about an hour if that helps.
I have two dead Shilen’s and two factory savage barrels

That would be helpful. I'd like to know how the factory barrels measure. If you can check the diameter just past where the threads end I'd appreciate it.

 

[Steel head]

Both my factory barrels are 1.6 long and 1.032 just past the end of thread.

Both the dead Shilens are 1.65 long and 1.051 just past the thread.

 

[tickridge]

does anyone know how deep the threads are cut in the bighorn SR3 action on a savage prefit

 

[tickridge]

would not the diameter of the barrel just past where the threads end be the inside dimension of the barrel nut less a few thousandths

 

[Steel head]

would not the diameter of the barrel just past where the threads end be the inside dimension of the barrel nut less a few thousandths

Factory barrel nut is 1.073 at the area over the end of the barrel and 1.021 at the threads

 

[Wannashootit]

Trinidad's book of drawings shows 1.055 x 1.565.

 

[Easy_E]

Are you turning the barrel I turn the shank to 1.055 ×20 and step up some to fill the gap under the smooth part of the nut.

 

[Mordamer]

Are you turning the barrel I turn the shank to 1.055 ×20 and step up some to fill the gap under the smooth part of the nut.

I am turning the blank down and I plan to do it very similar to what you show. Thank you to all who helped.

 

[Steel head]

I am turning the blank down and I plan to do it very similar to what you show. Thank you to all who helped.

One other note
With a real thin recoil lug the 1.65 showed about a thread and a half with a stock nut and NSS nut.

My current 7 mm barrel is a brux heavy Palma with the shank profiled to small savage

it came out really nice.

 

[tickridge]

just finished one last night the barrel nut dictates everything

 

[tickridge]

measure the length of the barrel nut subtract an eighth to determine the thread length. I d of nut determines diameter of barrel on muzzle end

 

[Mordamer]

measure the length of the barrel nut subtract an eighth to determine the thread length. I d of nut determines diameter of barrel on muzzle end

I didn't have the action, barrel nut, or a savage takeoff barrel in hand. I made the pre fit with 1.56 inches of threads and mailed it to the customer. He said it fit perfect.