Muzzle threading questions

[Noah Hutchens]

I know I’m going to catch a lot of flak for this but I’m trying to get my 375 H&H threaded for a suppressor partly because recoil control, partly because of hearing and also because my PH I booked my next hunt through says most of his concessions require suppressed firearms.

My local gunsmith I like is out of town for a few weeks to inspect it in person but after a brief phone call with him he’s unsure if it will work .

The barrel is a little thin at the muzzle, is there enough meat to thread it? I’ve tried to do a little looking online and I obviously don’t know anything about the process but if there isn’t enough meat to thread the barrel is it possible to put a “sleeve” on the muzzle of the barrel by soldering it to the barrel and then thread that sleeve?

I’m sure there’s some other way I haven’t thought of, or at least I hope there’s a way lol. Any gunsmiths have an opinion? It’s a 23in barrel so not really a lot of room to cut it back very much to still have a reasonable length right? Soooo how screwed am I?

 

[TheDoubleD]

What is the diameter of the barrel at the muzzle. Does the suppressor have a set thread pitch, or are different size threads available?

The front sight ramp will have to cut or moved back

 

[Noah Hutchens]

What is the diameter of the barrel at the muzzle. Does the suppressor have a set thread pitch, or are different size threads available?

The front sight ramp will have to cut or moved back

I can get the suppressor ordered in whatever thread I need. I understand on the front sight, that’s the least of my worries, it’s on by 2 screws.

Muzzle is .665

 

[Hogpatrol]

Clamp on option:

Custom Clamp-On Threaded Adapter - Witt Machine

CHECK BARREL CONCENTRICITY BEFORE INSTALLATION OF ANY SUPPRESSOR, NOT LIABLE FOR DAMAGE Milled from solid 416 stainless steel bar stock to exactly fit your barrel, available in nearly any caliber and with either 1/2-28 or 5/8-24 threads. Finish options include tumbled stainless (matte) as well...

wittmachine.net

 

[Rumrunner]

Clamp on option:

Custom Clamp-On Threaded Adapter - Witt Machine

CHECK BARREL CONCENTRICITY BEFORE INSTALLATION OF ANY SUPPRESSOR, NOT LIABLE FOR DAMAGE Milled from solid 416 stainless steel bar stock to exactly fit your barrel, available in nearly any caliber and with either 1/2-28 or 5/8-24 threads. Finish options include tumbled stainless (matte) as well...

wittmachine.net

Caution.

https://www.bbb.org/us/tx/childress/profile/gun-equipment/witt-machine-defense-llc-0815-99136742

 

[Teampowpow]

I’m not a gunsmith but have had many a gun threaded. I see no issue it doesn’t require that much, “meat”. Soon as I find a decent deal on a model 70 in 375hh for the kiddos that’s the first thing I’ll do as well…
A competent gunsmith with proper tooling will have that ready to go in no time…. The front sight will have to go or he will have to move it back, the good thing is it it is not a hooded sight

 

[Mark Biggerstaff]

Most will prefer .725 diameter on large bore (Over 30 cal) to allow enough shoulder for suppressor to seat.To do 5/8x24 threads. My machinist will not do at those measurements on over 30 caliber guns. If you try to do smaller diameter threads and bushing up to 5/8 the original barrel thickness to bore becomes thin and can compromise integrity of barrel.
Need to measure 3/4 inch below muzzle and then work way down barrel and see what taper is and where you get to at least .710-.725

 

[Noah Hutchens]

I guess another thing I need to figure out from the more knowledge folks is what is the minimum acceptable barrel length for the 375? As I said above I’m at 23” now. If I needed to cut back to say 20” to get the correct diameter on the barrel to safely thread would that be a big hindrance? Maybe even 19” or 19.5”? I don’t mind losing a little bit of length since the suppressor I am purchasing is 7.5” long but I don’t want to sacrifice too much velocity. However I know I only plan on taking shorter shots with the rifle, I.e. 100 yards or less or so since I have a dedicated 300 WM plains game rifle for the longer shots.

 

[samson7x]

Yes, easy job for a good smith. If necessary, they will add a threaded collar with larger OD to provide enough shoulder for the suppressor. Search for my thread for more details. I chopped mine to 20” without much loss in velocity.

Contact Longrifles Inc in SD, they are great to work with.

 

[Andrew62]

I guess another thing I need to figure out from the more knowledge folks is what is the minimum acceptable barrel length for the 375? As I said above I’m at 23” now. If I needed to cut back to say 20” to get the correct diameter on the barrel to safely thread would that be a big hindrance? Maybe even 19” or 19.5”? I don’t mind losing a little bit of length since the suppressor I am purchasing is 7.5” long but I don’t want to sacrifice too much velocity. However I know I only plan on taking shorter shots with the rifle, I.e. 100 yards or less or so since I have a dedicated 300 WM plains game rifle for the longer shots.

There are gun manufacturers producing .375's and 416's with 20" barrels. I personally own a Kimber .375H&H, I had the 24" barrel cut back to 20" then threaded. When I go to shoot my gun at the range I put on a muzzle brake, then before I go on a hunt I take off the brake, put on a threaded cap, check zero, then go hunting. This way I don't get beat up shooting it at the range and the guide loves it that I do not hunt with a muzzle brake.

If someone is wanting to use a .375H&H out to 300 yards, then yes, velocity may be important, but for dangerous game hunting between 30 to 100 yards, there is no buffalo on this planet that will know if the bullet was going 2400 fps or 2480fps.

Cut the barrel, get it threaded, go hunting!!

 

[Teampowpow]

I guess another thing I need to figure out from the more knowledge folks is what is the minimum acceptable barrel length for the 375? As I said above I’m at 23” now. If I needed to cut back to say 20” to get the correct diameter on the barrel to safely thread would that be a big hindrance? Maybe even 19” or 19.5”? I don’t mind losing a little bit of length since the suppressor I am purchasing is 7.5” long but I don’t want to sacrifice too much velocity. However I know I only plan on taking shorter shots with the rifle, I.e. 100 yards or less or so since I have a dedicated 300 WM plains game rifle for the longer shots.

 

[TheDoubleD]

.665 is pretty thin. AI-Google says 5/8-24tpi is pretty standard for .30 cal to .375 supressors. The major diameter of a 5/8-24 thread is .624.

.624 - .375 = .249/2 = .1245 wall thickness groove to bases of the .1245 inch.

Barrel is far to small for standard size supressor.

 

[Noah Hutchens]

.665 is pretty thin. AI-Google says 5/8-24tpi is pretty standard for .30 cal to .375 supressors. The major diameter of a 5/8-24 thread is .624.

.624 - .375 = .249/2 = .1245 wall thickness groove to bases of the .1245 inch.

Barrel is far to small for standard size supressor.

Excuse my ignorance but why would the wall thickness at .1245 be too thin? Maybe I’m searching the wrong information but online I’m finding that .12 is an acceptable wall thickness. Am I missing something(most likely)?

 

[samson7x]

.665 is pretty thin. AI-Google says 5/8-24tpi is pretty standard for .30 cal to .375 supressors. The major diameter of a 5/8-24 thread is .624.

.624 - .375 = .249/2 = .1245 wall thickness groove to bases of the .1245 inch.

Barrel is far to small for standard size supressor.

Are you a gunsmith? That wall thickness is plenty according to mine and I’ve had no issues with 100’s of rounds.

 

[BryceM]

Once installed over the threads, the base of the suppressor needs to fit squarely and butt up against something. The rim of remaining barrel would be very, very thin once the threads are cut. This wouldn’t support the base of the suppressor (or quick detach device) very well and could result in the suppressor moving (a huge problem with accuracy), or, even worse, the can could be misaligned resulting in a baffle strike and destruction of the can.

Also, if I’m thinking correctly, wall thickness should be determined from the minor diameter of the thread.

 

[jbirdwell]

I haven't had a problem with a thinner barrel on a 35 Whelen. I ended up going with a 1/2"-28 thread and then buying me a new end cap for my suppressor with that thread.

 

[samson7x]

Once installed over the threads, the base of the suppressor needs to fit squarely and butt up against something. The rim of remaining barrel would be very, very thin once the threads are cut. This wouldn’t support the base of the suppressor (or quick detach device) very well and could result in the suppressor moving (a huge problem with accuracy), or, even worse, the can could be misaligned resulting in a baffle strike and destruction of the can.

That’s why competent smiths add a collared flare. Another option, although much less common, would be to index directly on the muzzle. TBAC has such a muzzle device for their CB or HUB models.

 

[BryceM]

Sure, there are plenty of workarounds. A thread adapter is one. The TBAC options work too. Simply cutting a 5/8-24 thread and direct-threading a .375 can to the barrel probably isn’t the best idea.

 

[TheDoubleD]

Also, if I’m thinking correctly, wall thickness should be determined from the minor diameter of the thread.

Minor Diameter of the external thread on the barrel, correct---the bottom of the thread. The thinnest part of the barrel wall will be bottom of the thread. In this case about 1/8th inch. That is a very thin.



Now I confess my only experience with similar devices is installing muzzle brakes for a Muzzle brake company almost 40 years ago. These things were only about 2 inches or so long, but occasionally one would get shot down range or broke off--thin barrels always. Light weight mountain rifle were the rage back then.

Suppressors are, based only on what I see and read and no first hand knowledge, longer and heavier. This I believe would increase leverage making them more susceptible. to breakage or bending. I believe a suppresser for .375 would need to be pretty long, to be effective. Longer lever-basic physics.

 

[Noah Hutchens]

Minor Diameter of the external thread on the barrel, correct---the bottom of the thread. The thinnest part of the barrel wall will be bottom of the thread. In this case about 1/8th inch. That is a very thin.



Now I confess my only experience with similar devices is installing muzzle brakes for a Muzzle brake company almost 40 years ago. These things were only about 2 inches or so long, but occasionally one would get shot down range or broke off--thin barrels always. Light weight mountain rifle were the rage back then.

Suppressors are, based only on what I see and read and no first hand knowledge, longer and heavier. This I believe would increase leverage making them more susceptible. to breakage or bending. I believe a suppresser for .375 would need to be pretty long, to be effective. Longer lever-basic physics.

I understand that portion but from what I have read online 1/8th AKA .125” and seems like the consensus is you need at minimum .100 so even at .125 it should have plenty of thickness according to consensus? Again I might be missing something I don’t know lol.