We have some 14" 870's and a few Serbus that are dedicated for breaching. Is there enough material on the barrel to thread? Some of us would like to add standoff devices on the ends.
Gunsmithing Threading a Shotgun Barrel
- Thread starter Insayn
- Start date
Re: Threading a Shotgun Barrel
I have not threaded the outside of shotgun muzzles, but I have threaded the inside of a number of shotgun barrels.
There are lots of variations in shotguns and lots of ways to deal with them:
1) I am set up for 12 ga Rem Choke in a few pilot sizes.
32 threads per inch system.
I need a barrel to be .845" diameter.
2) Winchoke is also 32 TPI and needs .845"
3) The Tru Choke system with 44 TPI needs at least a .825" barrel muzzle.
4) The Tru Choke Thinwall aslo with 44TPI needs at least .805"
When Randy Ketchum does it [he is a real gunsmith], he cuts off the last 2", only to find that the bore is off center sometimes. I use the whole length of the barrel and spend too much time reaming out the old choke steel mass, so I have gone to a boring bar to prep for the reamer.
I also have a shotgun that has a bulge where the threads are. Stan Baker [famous late shotgun gunsmith] swaged the barrel out and then cut the threads. He is dead, but his shop is still operating.
Jack Belk, famous gunsmith, sometimes re sizes the outside of the barrel with rollers.
I sold a minty 870 yesterday for $200, with the caveat that Remington had reamed and tapped the choke off center and crooked, and so it shoots way to the left.
What does it all mean?
Shotgun barrels vary in:
1) barrel wall thickness
2) bore being centered in the barrel
3) chokes being centered in the muzzle
I have not threaded the outside of shotgun muzzles, but I have threaded the inside of a number of shotgun barrels.
There are lots of variations in shotguns and lots of ways to deal with them:
1) I am set up for 12 ga Rem Choke in a few pilot sizes.
32 threads per inch system.
I need a barrel to be .845" diameter.
2) Winchoke is also 32 TPI and needs .845"
3) The Tru Choke system with 44 TPI needs at least a .825" barrel muzzle.
4) The Tru Choke Thinwall aslo with 44TPI needs at least .805"
When Randy Ketchum does it [he is a real gunsmith], he cuts off the last 2", only to find that the bore is off center sometimes. I use the whole length of the barrel and spend too much time reaming out the old choke steel mass, so I have gone to a boring bar to prep for the reamer.
I also have a shotgun that has a bulge where the threads are. Stan Baker [famous late shotgun gunsmith] swaged the barrel out and then cut the threads. He is dead, but his shop is still operating.
Jack Belk, famous gunsmith, sometimes re sizes the outside of the barrel with rollers.
I sold a minty 870 yesterday for $200, with the caveat that Remington had reamed and tapped the choke off center and crooked, and so it shoots way to the left.
What does it all mean?
Shotgun barrels vary in:
1) barrel wall thickness
2) bore being centered in the barrel
3) chokes being centered in the muzzle
Re: Threading a Shotgun Barrel
The threading on these will be on the outside of the barrel. The manufacturer of the stand offs I am looking at is Royal Arms and has two different thread sizes, 0.875-24 (7/8-24) or 0.824-40. These are dedicated breaching shotguns where the shots are extremely close to contact. If anyone knows any gunsmiths that make a similar product or can recreate something similar to these send me the information.
The threading on these will be on the outside of the barrel. The manufacturer of the stand offs I am looking at is Royal Arms and has two different thread sizes, 0.875-24 (7/8-24) or 0.824-40. These are dedicated breaching shotguns where the shots are extremely close to contact. If anyone knows any gunsmiths that make a similar product or can recreate something similar to these send me the information.
Re: Threading a Shotgun Barrel
If you can buy the 12C-R extended choke tube...
If you can buy the breaching stand off that screws into that...
If your 11-87 takes choke tubes...
Then you can get away with no custom gunsmithing.
I have built custom stuff for shot gun breaches, and it is a lot of work.
If you can buy the 12C-R extended choke tube...
If you can buy the breaching stand off that screws into that...
If your 11-87 takes choke tubes...
Then you can get away with no custom gunsmithing.
I have built custom stuff for shot gun breaches, and it is a lot of work.
Re: Threading a Shotgun Barrel
The rounds we use kind of shy us away from using any choke style stand offs.
The rounds we use kind of shy us away from using any choke style stand offs.
Re: Threading a Shotgun Barrel
The prescribed way of getting around loads that do not choke at the old pressure [like cups of steel BBs] is with screw in chokes.
Where the threads are, there is no choke.
There can then be a choke with thick walls outside the breech.
The hoop stress is then very low at the threads.
If you are shooting a solid hardened steel slug, the size of the bore, it will not harm the threaded junction of the same inside diameter.
Call Royal Arms, and ask if your loads could affect one of their screw ins.
The prescribed way of getting around loads that do not choke at the old pressure [like cups of steel BBs] is with screw in chokes.
Where the threads are, there is no choke.
There can then be a choke with thick walls outside the breech.
The hoop stress is then very low at the threads.
If you are shooting a solid hardened steel slug, the size of the bore, it will not harm the threaded junction of the same inside diameter.
Call Royal Arms, and ask if your loads could affect one of their screw ins.
Re: Threading a Shotgun Barrel
Go to tromix.com
He has the stand off muzzle breaks and can thread the outside of your barre. i have some of his shark breaks and have one on a 45ACP on a smle conversian action and the break works perfectly as a stand off i have tried it out on a lock or two on some scrap doors and they work like they are supposed to. I also have frangible projectiles to play with in it.
So contact tromix Tony Rumore he will do the job of fitting them aswell as supplying them or you can have another gunsmith fit one to your barrel it is very easy to thread the outside of a shotgun barrel place the baddel in a chuck and the muzzle end into a live centre and you are good to go then you just have to turn the thread ditameter and then cut the threads it is a simple job just have to make sure the thread and barrel OD are compatable you want to use the largest thread that the barrel will allow.
Go to tromix.com
He has the stand off muzzle breaks and can thread the outside of your barre. i have some of his shark breaks and have one on a 45ACP on a smle conversian action and the break works perfectly as a stand off i have tried it out on a lock or two on some scrap doors and they work like they are supposed to. I also have frangible projectiles to play with in it.
So contact tromix Tony Rumore he will do the job of fitting them aswell as supplying them or you can have another gunsmith fit one to your barrel it is very easy to thread the outside of a shotgun barrel place the baddel in a chuck and the muzzle end into a live centre and you are good to go then you just have to turn the thread ditameter and then cut the threads it is a simple job just have to make sure the thread and barrel OD are compatable you want to use the largest thread that the barrel will allow.
