Thread shoulder for suppressor

[Snowbird]

When threading a thin contour, does it matter if you have a .10 shoulder if you're running a quick detach system like keymo? I'm struggling with what contour bbl to go with on a Tikka t3 that will allow 5/8x24 threads on a 20" bbl. I realize the threads alone need .650 but how much shoulder is needed and how do you know what a barrel will measure at a particular length? So far all is see are muzzle measurements for longer barrels and I'm just guessing at the other measurements.

 

[cohunt]

Usually need .700" or better for 5/8" threads, others have squeaked by with less though

 

[Bucklowery]

Usually your device has a spec from the manufacturer. I know my TBac had one for the adapter and for direct thread

Thanks

Buck

 

[Tac284]

I prefer a min of at least .040 per side for shoulders when doing any attachment. So for a 5/8" (.625 OD) I would want a .705 OD on the barrel at the muzzle end. Thunder Beast wants a little more than .040, others might be different than TB so check with them if you can. Good luck!

 

[Snowbird]

I prefer a min of at least .040 per side for shoulders when doing any attachment. So for a 5/8" (.625 OD) I would want a .705 OD on the barrel at the muzzle end. Thunder Beast wants a little more than .040, others might be different than TB so check with them if you can. Good luck!

This is what I was looking for. I'll either run an ultra 7 or nomad Lt on this barrel.

Thank you for all the replies

 

[bengineer]

I've been at this for 20 years. .040-.050 shoulder is a minimum. Thats a barrel OD of .1 over thread major diameter.
The larger the shoulder the better, up to a point. You don't want a bull barrel to drop to 1/2" threads; that can cause belling of the muzzle and kill accuracy.
If you end up with a thin barrel situation, your barrel can be threaded longer and a cone shaped piece can be added to build a shoulder. I had this done 8 years ago and have never had a problem on a 308 with a 5" Ultra.

 

[Terry Lightle]

Had my T3 20 inch 223 threaded 5/8 24 with no problems .Mine is a Silencerco Omega.Gunsmith said just enough.It is a factory barrel

 

[bengineer]

The off color metal is a stainless piece used as a false shoulder on a too-thin barrel. 8 years and running without troubles.