7MM STW shoulder angle

[eddywitay]

I have a question maybe someone can help me out I am wanting to headspace off the shoulder on my 7STW and was wondering what the right bump gage would be from sinclair thanks...

 

[jp]

When the cartidge was developed in the late 80's by Kenny Jarrett it had a 35degree shoulder. Hope this helps.

 

[pmarauder]

When the cartidge was developed in the late 80's by Kenny Jarrett it had a 35degree shoulder. Hope this helps.

Im pretty sure it is 25 degree. At least that is what my Sinclair bump gauge insert says on the side of it for my STW.

 

[eddywitay]

I thought Layne Simpson wildcatted that round.

 

[Calumet]

According to Wiki, the 7mm STW, was based on the 8mm Remington Magnum case, which had a shoulder angle of 25*.

Layne Simpson, a writer for Shooting Times simply necked it down to 7mm, & called it the 7mm Shooting Times Westerner.

http://en.wikipedia.org/wiki/8mm_Remington_Magnum

I'd guess, a little less recoil, & better long range ballistics was appropriate for the Westerner part of the name, for the long shots on Muleys often encountered in the West

Calumet

 

[eddywitay]

That's what I was thinking I put a 25 degree bump gauge on the shoulder and It kind of moved around a bit so than I tried a 35 as also mentioned and that seemed to fit a little better

 

[Dirtball]

The standard, used by every major manufacturer is 25*, just like the 8mm Rem Mag, 300 Win Mag, 264 Win Mag, 7mm Rem Mag, and so on.
Now "Custom Guns with Custom chambers can be ANYTHING the builder wants!

Dave

 

[jp]

you are right about Layne, But Kenny told me he built one of the first for Bob Nosler I believe. But that was a few years ago. Maybe my memory is slipping.. :-\

 

[BowGuy]

I have a question maybe someone can help me out I am wanting to headspace off the shoulder on my 7STW and was wondering what the right bump gage would be from sinclair thanks...

25 degrees is correct. Headspacing off the shoulder is always a good idea, especially when dealing with belted magnums.

 

[eddywitay]

I have a 25* Thanks for all the help guys