Threading Shotgun Barrel for Chokes

Gregory Gauvin · February 21, 2016, 11:44 PM

Years back I purchased a Remington 870 Express, 18.5" barrel 12ga pump. This was long before they came around with their tactical lines of shotguns. The price was right.

I have my clay guns. This shotgun was strictly meant for home defense purposes, in which, when my grandmother's house was being routinely burglarized, came with me to spend several nights there. It is also the only gun in my gun room with 5 rounds of 00 Buck shots on the stock and an ammo belt of shells. I.E., aside from my carry pistol that is loaded, the shotgun is my go to gun.

It is a fixed cylinder bore barrel, had a 4 shot magazine tube. I added a 2 shot extension (yes, I had to dremel down those dimples), barrel clamp with front sling swivel and an ATI heat-shield.

Obviously, I essentially created Remington's later 870 Tactical line shotgun, only, they can't accommodate a heat-shield

but do come threaded for Rem Chokes. Or at least, whatever their extended Rem choke is with the prongs.

I wanted to make this shotgun more versatile. Sure it breaks clays at 20 yards but is no good for any real clay shooting. I run a modified choke in my other shotguns for clays.

I just spoke with my gunsmith about having my cylinder bore barrel threaded for chokes. My smith has been around and knows guns like you know the sun is going to rise the next day. He had just finished unitizing my gas cylinder on my M14 and some trigger work...sighted in my Leupold Mk IV....3 rounds 1 hole. He's made firing pins for Type 14 Nambu pistols...he's a retired master gunsmith from Kimber.

Anyhow, despite what I read on the internet about shotgun barrels being able to be threaded for chokes, he told me this can not be done. Because the barrel is cylinder bore, it opens near the end, and couldn't be done. I would imagine remington's tactical shotguns with extended chokes are thin walled because they have to be reamed to be threaded thus having the choke extended. Nonetheless, has anyone ever attempted to thread a 18.5" 870 barrel for rem chokes? Can it be done?

I know I could just buy an aftermarket barrel. But, I'm not spending half the price of the shotgun on a barrel and have a barrel I never use sit and collect dust.

Gregory Gauvin · February 21, 2016, 11:56 PM

According to this website...for a shotgun to be reamed and threaded for chokes, there must be a minimum of .845" outside diameter. I just measured the barrel and it measured .900".

http://www.ktgunsmith.com/choketube.htm

What's your thoughts?

**4V50 Gary** · February 22, 2016, 12:41 AM

Brownell's sells a is special tool with which you can measure the thickness of the barrel. I think we were supposed to measure it at four points.

Roughedge · February 22, 2016, 07:39 AM

For Win-chokes it has to be .850 outside and you can do a Rem-choke at that but .875 is better . If you are .900 it wont be a problem. I have done a Rem-choke at .840 but it was paper thin at the muzzle and needed the choke installed at all times to keep from denting the edge.

Clark · February 22, 2016, 01:15 PM

I have the reamer, tap, and pilots from Brownells for Rem Choke.

My brother borrowed them because his 870 will not shoot straight.

But rather than put the barrel in his lathe, he clicked on a replacement barrel. I think a Hastings. Now it shoots straight.

Last month he sent a picture of him with the new barrel.

He still has my Remchoke reamer.

jmr40 · February 22, 2016, 04:45 PM

I'm pretty sure it could be done. I picked up a brand new 870 probably 20 years ago with a 28" barrel dirt cheap. Walmart had lost the box and had a Wingmaster priced $50 less than the Express, but without the box. I had it cut down to 24", that would have been cylinder too, and threaded for Remington tubes. I've read of others doing it to the same barrel you have.

FWIW, I don't really think it is cost effective. For about the same money or less you can buy a 20 or 21" barrel that is already threaded from the factory. I would just as soon have the extra 1.5-2.5".

By choosing shells carefully you can do more with the cylinder tube than you may think. Shoot some patterns and you might be surprised.

FITASC · February 22, 2016, 04:53 PM

There are thinwall chokes that can be installed. Briley in Houston is the 800# gorilla for that work. They've threaded some very thin barrels on some friends' old English double guns.
Otherwise, if there is enough material, Mike Orlen in MA can do the barrel work. You might call him; he gets great reviews on other sites and is fast and very reasonable on pricing.

Dixie Gunsmithing · February 22, 2016, 09:00 PM

With an 870 barrel cut back to 18.5 inches, I'd venture to say it is now thicker, at the muzzle, than it was before it was cut. Just measure the muzzle's bore, with a caliper, both inside and out. Subtract the ID from the OD, then divide by two to get the thickness, or if the calipers have a good knife edge to them, just measure the thickness, and it ought to be within a thou. That barrel ought to be pretty thick back at that length, due to the taper of the OD.

Gregory Gauvin · February 23, 2016, 07:20 PM

I measured my OD at .900" ID measured .725".

I gunsmith on ebay who does this work says it can be done, and has done several of them with no problems. I'm thinking...perhaps, my gunsmith doesn't own the reamer to do the job. It's an expensive tool and not something done frequently I suppose.

Gregory Gauvin · February 23, 2016, 07:28 PM

Doing the math there .900 - .725 = .0875".

That's about what I measured the wall thickness with my calipers. I got a reading of .0875 to .09". Kinda tricky to get precise measurement as the slightest angle of the calipers not perpendicular with the barrel with throw the reading off a few thous. Also, I'm inclined to believe the measurement differs the further you take the measurement in the bore. I tried my best to take the reading at the muzzle. I would imagine the walls thicken further back.

The finish on the barrel probably adds a thousandth or two, and most likely isn't uniform.

BeakSmasher · February 23, 2016, 11:01 PM

Is there anyone out there that will thread a 10 gauge for browning chokes? Every place I called directed me to briley, but they only do true chokes

Cowboy_mo · February 24, 2016, 09:42 PM

I'm not knowledgeable enough to quote the necessary thickness for this job but I know someone who is and does a heck of a job.

Mike Orlen (a member of this forum) did a great job threading the barrel on my Franchi AL-48 which was cylinder bore to start. His work was quick, quality, and very reasonable on the price. My suggestion is to "Ask Mike".

hoghunting · February 25, 2016, 02:01 PM

Quote:

Mike Orlen (a member of this forum) did a great job threading the barrel on my Franchi AL-48 which was cylinder bore to start. His work was quick, quality, and very reasonable on the price

Didn't realize Mike Orlen was a member of this forum, but very aware he is a member of www.shotgunworld.com and an excellent gunsmith.

http://www.shotgunworld.com/bbs/view...p?f=12&t=36237

johnwilliamson062 · February 26, 2016, 09:10 PM

http://poly-choke.com/choke.htm
I'm the only one who likes them, and its supposedly because I've never actually owned one, but there you go. The price includes installation.

I doubt you can have it threaded any cheaper.
You might be able to buy a used barrel cheaper.

Cowboy_mo · February 26, 2016, 09:29 PM

Had my barrel threaded and plus 3 chokes for less than your ///// poly choke /// option and don't have a muzzle heavy shotgun like you get with a poly choke.

FWIW, the first shotgun I ever owned was a Mossberg bolt action with a poly choke from the factory.

February 21, 2016, 11:44 PM	#1
Gregory Gauvin Senior Member Join Date: March 6, 2009 Posts: 368	Threading Shotgun Barrel for Chokes Years back I purchased a Remington 870 Express, 18.5" barrel 12ga pump. This was long before they came around with their tactical lines of shotguns. The price was right. I have my clay guns. This shotgun was strictly meant for home defense purposes, in which, when my grandmother's house was being routinely burglarized, came with me to spend several nights there. It is also the only gun in my gun room with 5 rounds of 00 Buck shots on the stock and an ammo belt of shells. I.E., aside from my carry pistol that is loaded, the shotgun is my go to gun. It is a fixed cylinder bore barrel, had a 4 shot magazine tube. I added a 2 shot extension (yes, I had to dremel down those dimples), barrel clamp with front sling swivel and an ATI heat-shield. Obviously, I essentially created Remington's later 870 Tactical line shotgun, only, they can't accommodate a heat-shield but do come threaded for Rem Chokes. Or at least, whatever their extended Rem choke is with the prongs. I wanted to make this shotgun more versatile. Sure it breaks clays at 20 yards but is no good for any real clay shooting. I run a modified choke in my other shotguns for clays. I just spoke with my gunsmith about having my cylinder bore barrel threaded for chokes. My smith has been around and knows guns like you know the sun is going to rise the next day. He had just finished unitizing my gas cylinder on my M14 and some trigger work...sighted in my Leupold Mk IV....3 rounds 1 hole. He's made firing pins for Type 14 Nambu pistols...he's a retired master gunsmith from Kimber. Anyhow, despite what I read on the internet about shotgun barrels being able to be threaded for chokes, he told me this can not be done. Because the barrel is cylinder bore, it opens near the end, and couldn't be done. I would imagine remington's tactical shotguns with extended chokes are thin walled because they have to be reamed to be threaded thus having the choke extended. Nonetheless, has anyone ever attempted to thread a 18.5" 870 barrel for rem chokes? Can it be done? I know I could just buy an aftermarket barrel. But, I'm not spending half the price of the shotgun on a barrel and have a barrel I never use sit and collect dust.

February 22, 2016, 12:41 AM	#3
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 21,874	Brownell's sells a is special tool with which you can measure the thickness of the barrel. I think we were supposed to measure it at four points. __________________ Vigilantibus et non dormientibus jura subveniunt. *Molon Labe!*

February 22, 2016, 07:39 AM	#4
Roughedge Senior Member Join Date: January 24, 2011 Location: Monroe,NC Posts: 669	For Win-chokes it has to be .850 outside and you can do a Rem-choke at that but .875 is better . If you are .900 it wont be a problem. I have done a Rem-choke at .840 but it was paper thin at the muzzle and needed the choke installed at all times to keep from denting the edge. __________________ The man that die's with the most stuff win's!

February 22, 2016, 04:53 PM	#7
FITASC Senior Member Join Date: December 6, 2014 Posts: 6,472	There are thinwall chokes that can be installed. Briley in Houston is the 800# gorilla for that work. They've threaded some very thin barrels on some friends' old English double guns. Otherwise, if there is enough material, Mike Orlen in MA can do the barrel work. You might call him; he gets great reviews on other sites and is fast and very reasonable on pricing. __________________ "I believe that people have a right to decide their own destinies; people own themselves. I also believe that, in a democracy, government exists because (and only so long as) individual citizens give it a 'temporary license to exist'—in exchange for a promise that it will behave itself. In a democracy, you own the government—it doesn't own you."- Frank Zappa

February 21, 2016, 11:56 PM	#2
Gregory Gauvin Senior Member Join Date: March 6, 2009 Posts: 368	According to this website...for a shotgun to be reamed and threaded for chokes, there must be a minimum of .845" outside diameter. I just measured the barrel and it measured .900". http://www.ktgunsmith.com/choketube.htm What's your thoughts?

February 22, 2016, 04:45 PM	#6
jmr40 Senior Member Join Date: June 15, 2008 Location: Georgia Posts: 10,831	I'm pretty sure it could be done. I picked up a brand new 870 probably 20 years ago with a 28" barrel dirt cheap. Walmart had lost the box and had a Wingmaster priced $50 less than the Express, but without the box. I had it cut down to 24", that would have been cylinder too, and threaded for Remington tubes. I've read of others doing it to the same barrel you have. FWIW, I don't really think it is cost effective. For about the same money or less you can buy a 20 or 21" barrel that is already threaded from the factory. I would just as soon have the extra 1.5-2.5". By choosing shells carefully you can do more with the cylinder tube than you may think. Shoot some patterns and you might be surprised.

February 22, 2016, 09:00 PM	#8
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	With an 870 barrel cut back to 18.5 inches, I'd venture to say it is now thicker, at the muzzle, than it was before it was cut. Just measure the muzzle's bore, with a caliper, both inside and out. Subtract the ID from the OD, then divide by two to get the thickness, or if the calipers have a good knife edge to them, just measure the thickness, and it ought to be within a thou. That barrel ought to be pretty thick back at that length, due to the taper of the OD.

February 23, 2016, 07:20 PM	#9
Gregory Gauvin Senior Member Join Date: March 6, 2009 Posts: 368	I measured my OD at .900" ID measured .725". I gunsmith on ebay who does this work says it can be done, and has done several of them with no problems. I'm thinking...perhaps, my gunsmith doesn't own the reamer to do the job. It's an expensive tool and not something done frequently I suppose.

February 23, 2016, 07:28 PM	#10
Gregory Gauvin Senior Member Join Date: March 6, 2009 Posts: 368	Doing the math there .900 - .725 = .0875". That's about what I measured the wall thickness with my calipers. I got a reading of .0875 to .09". Kinda tricky to get precise measurement as the slightest angle of the calipers not perpendicular with the barrel with throw the reading off a few thous. Also, I'm inclined to believe the measurement differs the further you take the measurement in the bore. I tried my best to take the reading at the muzzle. I would imagine the walls thicken further back. The finish on the barrel probably adds a thousandth or two, and most likely isn't uniform.

February 23, 2016, 11:01 PM	#11
BeakSmasher Junior Member Join Date: February 22, 2016 Posts: 6	Is there anyone out there that will thread a 10 gauge for browning chokes? Every place I called directed me to briley, but they only do true chokes

February 24, 2016, 09:42 PM	#12
Cowboy_mo Senior Member Join Date: June 23, 2010 Location: Missouri Posts: 1,039	I'm not knowledgeable enough to quote the necessary thickness for this job but I know someone who is and does a heck of a job. Mike Orlen (a member of this forum) did a great job threading the barrel on my Franchi AL-48 which was cylinder bore to start. His work was quick, quality, and very reasonable on the price. My suggestion is to "Ask Mike".

February 26, 2016, 09:10 PM	#14
johnwilliamson062 Junior member Join Date: May 16, 2008 Posts: 9,995	http://poly-choke.com/choke.htm I'm the only one who likes them, and its supposedly because I've never actually owned one, but there you go. The price includes installation. I doubt you can have it threaded any cheaper. You might be able to buy a used barrel cheaper.

February 26, 2016, 09:29 PM	#15
Cowboy_mo Senior Member Join Date: June 23, 2010 Location: Missouri Posts: 1,039	Had my barrel threaded and plus 3 chokes for less than your ///// poly choke /// option and don't have a muzzle heavy shotgun like you get with a poly choke. FWIW, the first shotgun I ever owned was a Mossberg bolt action with a poly choke from the factory.