Smallest muzzle diameter for 3/4 threads?

[Lonewolf74]

I'm curious what the smallest diameter at the muzzle would be to comfortably put 3/4-24 threads on? Is the typical rem sendero (.830) at the muzzle leave an adequate shoulder?

Thank you for your time and help,
Joshua

 

[V35BTC]

I wont do one with less than .050" of shoulder. Some will, but I wont. So that scenario you mentioned would be a no go for me.

 

[Lonewolf74]

Wouldn't a muzzle diameter of .830 leave a shoulder of .080 with 3/4-24 threads? .830 barrel diameter at muzzle minus .750 major diameter for threads equals .080 unless I'm missing something?

 

[FEENIX]

I'm curious what the smallest diameter at the muzzle would be to comfortably put 3/4-24 threads on? Is the typical rem sendero (.830) at the muzzle leave an adequate shoulder?

Thank you for your time and help,
Joshua

Most muzzle brake manufacturers (i.e., https://muzzlebrakesandmore.com/beast-2-piece-brakes) have muzzle diameter range recommendations; contact them and the GS that will thread your barrel.

 

[Lonewolf74]

Alright…did a search and realized I asked this same question a couple years ago and got all the answers I was looking for.

Man I'm too young to be this dang forgetful…

 

[Lonewolf74]

@V35BTC; I asked a fool question after your post so please disregard it. After giving it a thought I realized your saying you want .050 of shoulder, which means the muzzle diameter would need to be .100 bigger then the major thread diameter.

Thinking is difficult before 6am…

 

[V35BTC]

@V35BTC; I asked a fool question after your post so please disregard it. After giving it a thought I realized your saying you want .050 of shoulder, which means the muzzle diameter would need to be .100 bigger then the major thread diameter.

Thinking is difficult before 6am…

Lol……I do it daily

 

[Mmac52280]

@V35BTC; I asked a fool question after your post so please disregard it. After giving it a thought I realized your saying you want .050 of shoulder, which means the muzzle diameter would need to be .100 bigger then the major thread diameter.

Thinking is difficult before 6am…

For woke liberals, thinking is impossible 24/7....count your blessings.

 

[kgunz11]

The common rule of thumb is .050" per side, or .100" total, minimum. Even that's not a lot and the runout in the barrel can make that iffy at times.

 

[Kiwi Greg]

You would be way better off with a 3/4 x 24 thread on a Sendero barrel with a 40 thou shoulder than going down to 5/8 x 24

The bigger the thread the greater the surface contact area on the shoulder, 40 thou on a 1/2" thread is miles less than on a 3/4

Unless you are using a 24" Crescent to tighten it a 20-30 thou shoulder on the bigger threads works great

Some go down to 10-15 thou to get as far away from the bore as possible

I have 15 different threads available in a couple of my brake models to accommodate most barrels sensibly

 

[Lonewolf74]

Thanks for the reply Kiwi; this has been more my train of thought as well. Better to keep as much material around the muzzle as possible even if it cost a little less shoulder.

 

[tobnpr]

My criteria when it comes to threading for muzzle devices depends largely on whether it's a brake- or a suppressor.
In your case, I would probably be OK with threading for a brake, assuming the bore isn't more than a few thousandths out of being concentric with the barrel OD. This isn't usually an issue most barrels (certainly not upper tier ones). Keep in mind that however much the bore is "out" of being concentric reduces your shoulder by the same amount. Brakes are much shorter than suppressors, so perfect concentricity is not quite as critical. I'll cut class 3 threads for best fitment, and using Rocksett to make sure the brake cannot vibrate loose snug it up lightly against the shoulder. Minimal shoulder will provide correct alignment, Rocksett will make sure it stays that way. You don't need to rely on using a lot of torque (which could crush/deform a minimal shoulder) with this method.

So why the 3/4" threads, rather than 5/8"? What caliber are we talking about? Barrel wall thickness is also an important consideration. As mentioned, it's best to use the largest thread OD practical, as this maximizes barrel wall thickness- plenty of evidence that being too skinny here can cause the bore to bell-mouth and cause accuracy issues. I've seen this using precision gage pins...

If it's to be able to swap an existing 3/4" suppressor to another rifle, many manufacturers offer QD mounts that will index off the muzzle rather than using a shoulder- just did one last week because of the same situation with having inadequate OD on a customer's sporter barrel.

 

[Lonewolf74]

Currently what I have in mind is a Bartlien carbon wrapped barrel in 30 caliber that I have. It will be a 300 WM or 300 PRC. I haven't actually measured to double check but it's a sendero contour and I'm assuming it should finish right around .830. An SRS muzzle brake is all I have in mind for it right now but I wouldn't rule out a suppressor in the future.

In general I feel that 300 WM and up should be threaded 3/4 or left unthreaded if a smaller contour but this is just my theory on it.

 

[FEENIX]

Currently what I have in mind is a Bartlien carbon wrapped barrel in 30 caliber that I have. It will be a 300 WM or 300 PRC. I haven't actually measured to double check but it's a sendero contour and I'm assuming it should finish right around .830. An SRS muzzle brake is all I have in mind for it right now but I wouldn't rule out a suppressor in the future.

In general I feel that 300 WM and up should be threaded 3/4 or left unthreaded if a smaller contour but this is just my theory on it.

Do not overcomplicate it unnecessarily; my recommendation is still the same as #4, regardless of barrel contour or caliber/cartridge. I have been using muzzle brakes since 2003, and most of my rifles have a muzzle device. I have three 300 Win Mags with different muzzle diameters; one has 1/2-28" and the other two have 5/8-24" both my suppressors are also 5/8-24. If you plan on having a suppressor, have it threaded direct (my preference over an adapter), the same as your muzzle brake? Good luck!