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1.125" Tenon Thread

A chamber/tenon is part of a pressure vessel. Hoop strength refers to how much outward circumferential pressure a pressure vessel can withstand.
So elastic deformation of the chamber is expected? There's clearance between the thread roots and crests.
In order for any load to be placed on the receiver threads, the barrel/chamber would need to expand.
Doesn't make sense to me that this could occur and that the chamber would return to precisely the same dimensions every time the rifle is fired.

But, I'm not an engineer.
 
Let's look at the WHOLE picture.
Bolt nose has to be big enough for extractors to work properly for Lapua size cases.
For many custom actions that means a .750" diameter bolt.
Which leads to 1.125" threads. The reason, to get enough surface area on the lugs and you need clearance to EDM the raceways because of the larger diameter bolt lugs.
I've done hundreds of 338 Lapua barrels on 1.0625" threads BUT not with a conventual setups. Separate bolt heads and barrel extensions designed to handle the load.
Better to follow rule #1 " don't do anything to make the phone ring" and Rule #2 " It's OK to say no"
 
So elastic deformation of the chamber is expected? There's clearance between the thread roots and crests.
In order for any load to be placed on the receiver threads, the barrel/chamber would need to expand.
Doesn't make sense to me that this could occur and that the chamber would return to precisely the same dimensions every time the rifle is fired.

But, I'm not an engineer.
It's not the root and crest. It's the flanks of the threads that carry the load. And yes the barrel expands, the receiver expands and they all go back to the same place as long as you don't exceed the yield strength of the steel.
I once had a 22-250AI the chamber was expanded by .009". That required a new bolt as well as setting the barrel back. Remington action.
 
When Remington brought out the Ultra Mag, they stayed with the regular 1 1/16 16TPI found in every other Remington from the XP 100 all the way up. The Ultra has a standard operating pressure of 65,000 psi.

Dave Tooley makes some good points in that there are other considerations.

For what it is worth, if the hoop strength is the big concern with a 1 1/16 tenon, you could always go to a chrome moly barrel.
 

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