Minimum muzzle diameter for 1/2x28 threads

[Elkeater]

So I have a Silencerco Harvester EVO sitting in jail right now and realized that all my rifles are threaded except one. My wife's little Weatherby Vanguard youth model in 7-08 Rem is not threaded. It would actually be a sweet little suppressed rifle with the short stock and 20" barrel running 113gr shock hammers at 3,000fps.

My question is what's the minimum muzzle diameter for cutting 1/2x28 threads. This one is only .560" at the muzzle right now and I'm assuming 5/8x24 is out of the question but I'm wondering if 1/2x28 would be doable.

Could also have it cut to 16" where it's .625" diameter.

Can one of the gunsmiths on here help with this?

Thanks

 

[FEENIX]

So I have a Silencerco Harvester EVO sitting in jail right now and realized that all my rifles are threaded except one. My wife's little Weatherby Vanguard youth model in 7-08 Rem is not threaded. It would actually be a sweet little suppressed rifle with the short stock and 20" barrel running 113gr shock hammers at 3,000fps.

My question is what's the minimum muzzle diameter for cutting 1/2x28 threads. This one is only .560" at the muzzle right now and I'm assuming 5/8x24 is out of the question but I'm wondering if 1/2x28 would be doable.

Could also have it cut to 16" where it's .625" diameter.

Can one of the gunsmiths on here help with this?

Thanks

You can get a 1/2-28" to 5/8-24" adapter; however, it is best to have a competent gunsmith build it for you. Good luck.

 

[Elkeater]

You can get a 1/2-28" to 5/8-24" adapter; however, it is best to have a competent gunsmith build it for you. Good luck.

I can use either 1/2-28 or 5/8-24 with that can. So I'm not too worried about adapters and all that. I've got a good gunsmith already but I'm just wondering if I need to get a new barrel and have it cut and chambered and all that.

 

[FEENIX]

I can use either 1/2-28 or 5/8-24 with that can. So I'm not too worried about adapters and all that. I've got a good gunsmith already but I'm just wondering if I need to get a new barrel and have it cut and chambered and all that.

It is best to consult with your gunsmith.

 

[tobnpr]

This one is only .560" at the muzzle right now and I'm assuming 5/8x24 is out of the question but I'm wondering if 1/2x28 would be doable.

Given that 5/8" requires .625 just for the threads, much less a torque shoulder- not even close.

1/2" will not work either- unless the mount is designed for, or can be modifed to index on the muzzle.
You'd have roughly only .030 shoulder which is entirely inadequate for a suppressor mount.

You'll need a 1/2" threaded mount that will index off a flat muzzle in order to fit that barrel with a can.

 

[Elkeater]

I'm thinking new barrel it is.

Then the question becomes.243 win or 7-08 Rem? I hate the gun rabbit hole.

 

[xr650rRider]

The Kimber Mountain rifles have 7/16"-28

Kimber 84M Adirondack Muzzle Brake – 7MM/.280 CAL

Marked 7MM/.280 CAL, this stainless steel muzzle brake with 7/16-28 threads and 0.59” O.D. is for the 84M Adirondack rifle chambered in 7mm-08 Rem. Twenty eight optimally positioned gas ports help to reduce felt recoil, and the included tool can be used to remove or install the brake. 4100234

store.kimberamerica.com

Thread adapter

Muzzle Thread Adapter

This stainless steel adapter easily allows you to add an aftermarket muzzle brake or suppressor to your Kimber mountain rifle, converting a 7/16 x 28 threaded muzzle to a 5/8 x 24 threaded muzzle. For threaded barrels only.

store.kimberamerica.com

 

[tobnpr]

Well, Kimber may think that's fine, but I wouldn't touch it.
1/2" on a .30 cal is pushing it- roughly .075 of barrel wall thickness. Most smiths regard .100 as a safe minimum.
I've done this- but I won't go any thinner than that.

There's only .024 diff between 7mm and .30 cal- but going all the way down to 7/16" results in much less barrel wall thickness.
Minor diameter of 7/16-28 is .395, subtract .284 and you've got only .055 barrel wall thickness.

Even if you find a smith willing to do it, you're dealing with a fugly adapter.
Suggest you contact Silencerco to see which of their 1/2" mounts would be most suited to be modified to index off the muzzle.

JMO. Good luck with it.

.

 

[Elkeater]

Well, Kimber may think that's fine, but I wouldn't touch it.
1/2" on a .30 cal is pushing it- roughly .075 of barrel wall thickness. Most smiths regard .100 as a safe minimum.
I've done this- but I won't go any thinner than that.

There's only .024 diff between 7mm and .30 cal- but going all the way down to 7/16" results in much less barrel wall thickness.
Minor diameter of 7/16-28 is .395, subtract .284 and you've got only .055 barrel wall thickness.

Even if you find a smith willing to do it, you're dealing with a fugly adapter.
Suggest you contact Silencerco to see which of their 1/2" mounts would be most suited to be modified to index off the muzzle.

JMO. Good luck with it.

.

Honestly it's easier to just have a new barrel screwed on by the time I've had to have it threaded then go find an adapter.

Thinking I'll just keep an eye out for either a .284 or .243 blank that I can have chopped to maybe 16" or 18" and call it good

 

[JuddL]

Thunder Beast Arms Corporation [TBAC] | Tech | THREAD SPECIFICATIONS

You need a recommended .600 for a 1/2" thread so you could cut it down to probably around 18". I have seen people go smaller and rokset on a brake but I don't like stuff under spec.

Good luck!

 

[khmplus]

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[jrock]

1+ On the Thunder Beast thread spec chart as a way to KISS
I talked to a service person at Silencer Co. and they recommended a 0.10" shoulder for mounting a suppressor. They also said to ask the smith that will do the threading.
I talked to a couple barrel makers and they didn't think 0.10" was required.
It seems smiths thread based on their expected level of risk. I see a wide spread of "minimum" values.

 

[Nevadajim]

Given that 5/8" requires .625 just for the threads, much less a torque shoulder- not even close.

1/2" will not work either- unless the mount is designed for, or can be modifed to index on the muzzle.
You'd have roughly only .030 shoulder which is entirely inadequate for a suppressor mount.

You'll need a 1/2" threaded mount that will index off a flat muzzle in order to fit that barrel with a can.

For the problem of not having enough dia. for the torque shoulder we have threaded barrels with a longer length of threads and used a jam nut to locate and secure the muzzle device.

 

[tobnpr]

Brakes are a different animal than suppressors, and I treat them as such when making these types of decisions.
I've installed brakes with minimal shoulders, using Rocksett to secure them rather than relying on torque where you'd crush the shoulder with the necessary torque.

This is plain geometry. A brake that's an inch or two long- is much more forgiving than a 10" long suppressor in an application where concentricity is critical. I still think a mount that indexes on the muzzle is the best option from a technical and aesthetic perspective.

JMO, YMMV.