Barrel shoulder size vs thread size

makintrax73

Joined: Mar 2009

Posts: 11374

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IL, USA

Posted: 3/8/2026 2:13:16 PM EDT

Let's say you are threading a barrel blank on a lathe for a rifle barrel that threads into a single shot action.

Your thread size is 1" x 16" tpi.

The blank is only 1.062" OD, so say the shoulder OD cleans up at 1.050".

This leaves you with an engagement between the face of the barrel shoulder and the face of the action only .025" wide.

Problem? Is there a minimum difference commonly used to register the barrel shoulder properly to the action?

TonyRumore

Member

Joined: Feb 2001

Posts: 5107

EE: 100% (61)

OK, USA

Posted: 3/24/2026 10:11:23 AM EDT

[Last Edit: TonyRumore][Edited] [#1]

I don't know if there is a "standard", but I'm good with .050".
.025" seems a bit dicey, but will probably work. However, I would secure it with Loctite and not a shit ton of torque.

Tony

makintrax73

Joined: Mar 2009

Posts: 11397

EE: 0% (0)

IL, USA

Posted: 3/26/2026 9:48:45 AM EDT

[#2]

I ended up simply buying a 1.25" blank. I found out the land to land measurement on the smaller barrel is .346" and the pilot on my chamber reamer is .349. It was an either or situation so decided just to buy the correct blank and not screw around with it.

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Barrel shoulder size vs thread size

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Barrel shoulder size vs thread size

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Barrel shoulder size vs thread size