Gunsmithing - minimum barrel size to thread for 5/8-24 mount (2024)

What is the smallest barrel diameter that I can have threaded 5/8-24 for a new suppressor?

I have one that measures .64, and I assume anything over .625 can be threaded 5/8-24 with success, is this right?

Re: minimum barrel size to thread for 5/8-24 mount

Ya that's right. Just did one on a Rem 300 Ultra. Works good. Not much shoulder to stop against but can be done.

Re: minimum barrel size to thread for 5/8-24 mount

I like to see .050" min for a shoulder so to thread 5/8 I like to see at least .725" to start with.

Re: minimum barrel size to thread for 5/8-24 mount

What would a narrow shoulder affect? What difference could the suppressor stopping against the shoulder vs the suppressor bottoming out on the threads? I can imagine preference for the shoulder as the stop, but if the threads are spec and tight, it should not matter I think.

Re: minimum barrel size to thread for 5/8-24 mount

if you can't stop it at the shoulder then stop it on the muzzle crown. If you just use the threads it will always be changing - no definitive stop.

Re: minimum barrel size to thread for 5/8-24 mount

Makes sense, thanks guys.

Re: minimum barrel size to thread for 5/8-24 mount

If you're using a thread mount vs. QD mount suppressor and there is no shoulder (square that is) you are relying on the concentricity of the threads to your bore...and that of the threads in the can. I'd rather have a little shoulder on the barrel with the threads cut to the suppressors manufacturers spec.

Re: minimum barrel size to thread for 5/8-24 mount

my wsm is .70 at the muzzle and i have just enough shoulder to say I have a shoulder. Mine this threaded for a muzzle break, I could put my suppressor on but I think I would not want to hang a can off that small of a barrel

Re: minimum barrel size to thread for 5/8-24 mount

I am considering a TBAC threadmount, so the square shoulder comment seems dead on. Seems the ideal would be a proud shoulder exactly aligned perpendicular and concentric to the bore.

BTW I am purchasing the suppressor for my 700 AAC-SD but my question is related to threading a Tikka and another Remington to use the same TBAC.

Re: minimum barrel size to thread for 5/8-24 mount

If your suppressor is counterbored for threads without relief cuts you may need .745 to get the same .05" a side of actual metal contact.

Re: minimum barrel size to thread for 5/8-24 mount

counterbored for threads without relief cuts

Could you explain this more please?

Re: minimum barrel size to thread for 5/8-24 mount

Just curious, couldn't a threaded collar be made and cross-pinned pinned or soldered in place to act as a shoulder?

Re: minimum barrel size to thread for 5/8-24 mount

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Beef</div><div class="ubbcode-body">Just curious, couldn't a threaded collar be made and cross-pinned pinned or soldered in place to act as a shoulder? </div></div>

Sure.... concentricity would be a question as well as the barrel whip would be something fierce I would think.

Re: minimum barrel size to thread for 5/8-24 mount

Concentricity shouldn't be a problem since i suspect the barrel would be threaded in a lathe and the collar could then be installed and turned down quite small and trued on the lathe. Barrel harmonics would be more affected by the mass of a suppressor on a thin barrel I suppose.

Re: minimum barrel size to thread for 5/8-24 mount

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Beef</div><div class="ubbcode-body">Just curious, couldn't a threaded collar be made and cross-pinned pinned or soldered in place to act as a shoulder? </div></div>

Ding Ding Ding Ding Ding we have a winner.

Re: minimum barrel size to thread for 5/8-24 mount

I am considering a #3 contour Brux barrel for my lightweight hunter build. Gonna go 16.5 inches to keep it handy with the suppressor (I have an SWR Omega now, but am considering some iteration of a titanium lightweight can). According to my math, that contour should finish at about .715 at 16.5 inches. That would leave a .045 shoulder with 5/8x24 threads. Can I get away with that or will I need to consider going to a 9/16x24 thread pitch? Also, that contour should be stiff enough with that short a tube right? Again, this is a hunter, not a tactical/match rifle.

Re: minimum barrel size to thread for 5/8-24 mount

I generaly try to keep at least .030 per side over therad diameter. For a 5/8 x24 anything over .680 at the shoulder is fair game.

Re: minimum barrel size to thread for 5/8-24 mount

Just measured the ID of the endcap on my suppressor. It is relieved slightly so the diameter is .640. That should leave a ~.038 shoulder of actual metal-to-metal contact (muzzle at .715 OD). Seems mighty thin to me.

Re: minimum barrel size to thread for 5/8-24 mount

You guys that have experience shooting with suppressors on the smaller contours, how was accuracy and how did the rifle balance for you? Obviously it will be front heavy, did you find it acceptable? Were they finicky bastards to get to shoot??

EDIT:
Also, be it good or bad, please report the muzzle OD or contour used.

Re: minimum barrel size to thread for 5/8-24 mount

I have a #3 PacNor in .22BR that I use for coyote hunting. I believe it is .625 at 22". I actually think it is actually easier to tune with the suppressor on. Seems to dampen the harmonics of the light barrel. Hope this helps. Paul.