5/8-24 on Sporter Barrel

[slowelk]

TLDR - Muzzle shoulder experiences - neutral or negative.

I have a CGS Hyperion K with my name on it, but not yet off to the ATF. The Hyperion can directly thread onto any 5/8-24 threaded barrel, but the shoulder must be at least .740” behind the threads, and even then the thread engagement is less than ideal. I got in touch with the designer, and one of the guys behind pew science and we discussed the sig taper, and their thread adapter. The taper, and thus the adapter creates a better seal and significantly more thread engagement. I want to spin this onto my tikka lite barrel with the adapter, but don’t want to chop too much barrel off.

Josh from pew science told me “If the barrel is ~.630” or greater at the muzzle, then it can be threaded 5/8x24 with a muzzle shoulder. I highly doubt they made the barrel less than .630” at the muzzle. External 5/8x24 threads should be .617-.623 in major diameter.”

Obviously this is not something commonly considered, at least on this forum.

The attached diagram is what Josh referenced.

Does anyone have experience with a muzzle shouldered supressor or brake? Any negative impacts, primarily precision impacts?

Adapter pic attached for reference.

 

[Wapiti1]

Yes, I have used a muzzle shoulder on thin barrels with brakes. No, it doesn't cause any issues. It's the same thing as externally shouldering and has the same requirements of proper alignment with good thread fit. The only caveat is it needs a little more precision in the length of the thread tenon so you don't have a visible gap on the outside.

It's a straightforward machining operation no different than threading for an external shoulder.

Setup is the critical part.

Jeremy

 

[slowelk]

Yes, I have used a muzzle shoulder on thin barrels with brakes. No, it doesn't cause any issues. It's the same thing as externally shouldering and has the same requirements of proper alignment with good thread fit. The only caveat is it needs a little more precision in the length of the thread tenon so you don't have a visible gap on the outside.

It's a straightforward machining operation no different than threading for an external shoulder.

Setup is the critical part.

Jeremy

Thanks for your reply. Josh said it was important to find a good smith or machine shop to do the work, similar to what you suggested. Any suggestions?

 

[Wapiti1]

Do you want to stay in MT, or ship it? Dennis Olsen in Plains is good. I've heard good things about Coffin in Victor, but have not used him. Gentry in Belgrade does good work, but I've heard lead times are out there.

Out of MT, Karl Kampfeld is good. Shean Magan (Shooter71) gets good press. Others, I'm sure have some recommendations. I do my own work, so rarely use anyone's services.

Jeremy

 

[bigbuckdj]

I cant help you with your threading question but I was listening to the silencer central guy on a podcast recently about how they have CNC machines dedicated only to threading barrels and they run all day, every day.
It is probably worth giving them a call to see if they have encountered your issue. I have a similar issue with my old 270 WSM that I want to thread a hyperion onto.
Barrel Threading Services

They include this chart in their FAQ