barrel threading question

jacack

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Sep 21, 2002
Messages
480
i sent a encore/ bullberry 24inch 45/70 barrel to silencer central to have them thread it 5/8 24 for a suppressor i have and got a email back saying they couldnt do it email response below

Unfortunately we cannot cut and re-crown your Bullberry Barrel as the recoil lug is too large to fit into our machine. Because of this, the muzzle of the barrel will not pass through the face of the lathe before the recoil lug hits the back of the machine.

do they use some odd machine? i dont really understand the issue unless the head/chuck part is so big but if thats true how do they thread any short barrels?

either way, now i need someone else to do it and there is nobody close to me that i know of so looking for suggestion on who to send it to .

i want to cut it to 20" and thread it for the can.

thanks
 

TC338

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Sep 13, 2015
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Central Oklahoma
i sent a encore/ bullberry 24inch 45/70 barrel to silencer central to have them thread it 5/8 24 for a suppressor i have and got a email back saying they couldnt do it email response below

Unfortunately we cannot cut and re-crown your Bullberry Barrel as the recoil lug is too large to fit into our machine. Because of this, the muzzle of the barrel will not pass through the face of the lathe before the recoil lug hits the back of the machine.

do they use some odd machine? i dont really understand the issue unless the head/chuck part is so big but if thats true how do they thread any short barrels?

either way, now i need someone else to do it and there is nobody close to me that i know of so looking for suggestion on who to send it to .

i want to cut it to 20" and thread it for the can.

thanks
I had checked on this in the past as well, I was told that in order to have an encore barrel threaded, you had to have it done at the manufacturer. They would thread the barrel before the recoil lug was welded to the barrel.
 

biednick

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Jun 3, 2022
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Ohio
There's a hole that passes all the way through the headstock of the lathe. It lets you take long pieces of stock, pass them all the way through the chuck, and clamp them near the end you'll be working on. It's called a spindle bore. The size of this hole varies. If the distance from the bore of your barrel to the farthest point on the recoil lug is greater than the radius of the spindle bore and the barrel is too short to leave the recoil lug hanging out the end of the spindle opposite the chuck they won't be able to thread it with the lug attached. Encores have pretty big lugs, so they'd need a big spindle bore to thread it. Other barrels, like ARs and most bolt actions, can easily be removed from the action if this is a problem. Since Encores are welded there's no way to remove it.

I can't help with a recommendation for someone who can do the work, but hopefully this explains the limitation and why your Encore barrel is more of an issue than other barrels. There's other ways to fixture a barrel for threading, but a low price high volume shop isn't going to take the time to change things around for one barrel.
 
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tobnpr

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May 30, 2013
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564
^^^
Threading between centers isn't an issue, it gets a bit more complicated because of possible re-crowning that may be needed after sticking a live center into the muzzle to do it. I've used the brass "crown savers" when threading between centers for brakes but wouldn't rely on them for the perfect concentricity needed for cans. A snug fitting piloted "plug" would need to be machined to fit the bore (or Manson makes them to use with reamer bushings).


Beyond that- 5/8" threads wouldn't work anyway.
Grooved diameter of your barrel is .458.
The minor diameter of a 5/8"-24 thread is approx. .575- this leaves you with a barrel wall thickness of only .058 which is inadequate to prevent bell-mouth at the muzzle, you need minimum .100.

You need to go minimum 11/16" threads on a .45 cal bore.
 

biednick

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Jun 3, 2022
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Ohio
^^^
Threading between centers isn't an issue, it gets a bit more complicated because of possible re-crowning that may be needed after sticking a live center into the muzzle to do it. I've used the brass "crown savers" when threading between centers for brakes but wouldn't rely on them for the perfect concentricity needed for cans. A snug fitting piloted "plug" would need to be machined to fit the bore (or Manson makes them to use with reamer bushings).


Beyond that- 5/8" threads wouldn't work anyway.
Grooved diameter of your barrel is .458.
The minor diameter of a 5/8"-24 thread is approx. .575- this leaves you with a barrel wall thickness of only .058 which is inadequate to prevent bell-mouth at the muzzle, you need minimum .100.

You need to go minimum 11/16" threads on a .45 cal bore.
It'll need to be recrowned after chopping off the 4", so damaging the crown while threading wouldn't be a concern. I'd probably do it between centers then use an appropriately piloted crown cutter to crown it.
 
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jacack

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Sep 21, 2002
Messages
480
^^^
Threading between centers isn't an issue, it gets a bit more complicated because of possible re-crowning that may be needed after sticking a live center into the muzzle to do it. I've used the brass "crown savers" when threading between centers for brakes but wouldn't rely on them for the perfect concentricity needed for cans. A snug fitting piloted "plug" would need to be machined to fit the bore (or Manson makes them to use with reamer bushings).


Beyond that- 5/8" threads wouldn't work anyway.
Grooved diameter of your barrel is .458.
The minor diameter of a 5/8"-24 thread is approx. .575- this leaves you with a barrel wall thickness of only .058 which is inadequate to prevent bell-mouth at the muzzle, you need minimum .100.

You need to go minimum 11/16" threads on a .45 cal bore.
ok,i will ask about that, i have a 458 socom with this break on it and wanted to be able to swap the break and can between the 458 and 45/70

and the 458 is 5/8 24

 

tobnpr

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May 30, 2013
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564
ok,i will ask about that, i have a 458 socom with this break on it and wanted to be able to swap the break and can between the 458 and 45/70

and the 458 is 5/8 24

That's just "my" standard. You'll find other smiths may feel differently, on any number of these types of standards- minimum shoulders for brakes and suppressors, barrel wall thickness are just examples. With .050-.060 barrel wall the muzzle isn't going to self destruct- but there are very real potential accuracy issues when you get too skinny. Chad at LRI explains it on his website if you're not familiar with this:

Last, the caliber and cartridge for a particular setup must be considered. As a rule, LRI requires a minimum of .100" of wall thickness between the groove diameter of the barrel and the root diameter of the thread being machined to the muzzle. This value is judgement-based as well. A 300-378 Weatherby Magnum is a powerful cartridge with muzzle pressures significantly higher than a 308 Winchester at a given barrel length. Wall thickness should be increased accordingly.

Our experience has shown that a thin wall muzzle has the potential to "bell mouth" over time. When a crown bell mouths, the accuracy of the rifle suffers. You as the user may be compelled to think the barrel "let go" due to throat erosion when it's actually because the muzzle was threaded with too thin of a wall thickness.
 

Harry Knutz

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Southern Utah
Send it to Bulberry in Ut, They can do it no problem. But as others have mentioned, Threading between centers is something any Gunsmith can do. A jig can also be used, Like a viper jig, It may need to be modified for the lug. But it seems to me like the company you sent it to is stuck doing things one way and doesn't think outside the box.
 

JuddL

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Jul 24, 2019
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DFW
Lots of folks don’t understand in this thread. Additionally, there are lots of reasons folks turn down work…many having nothing to do with ability.

OP - sounds like the gentleman’s spindle bore isn’t large enough for the hinge lug. There are guys with bigger machines and folks with smaller who might do this between centers (tobnpr has some good reasons why not to do it that east). If I was you, that’s not how I’d want it done for suppressor usage.

Here is someone that will do it cheap, fast and right…normally you only get two of those but this guy is legit. https://class3machining.com/

Good luck, I just sold my 7-08ai 16” Encore…awesome little rifle.
 
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