Add a Screw In Choke Tubes to a Shotgun

[garandsrus]

Hi,

I have four shotgun barrels (20ga) that currently have fixed chokes. I would like to convert them to use screw in chokes. Three of the barrels currently have a Modified choke, one is Skeet. I may not convert the skeet barrel. Two of the barrels are for a Rem 870 and two are for H&R Single shot shotguns.

What is involved in adding screw in chokes to a shotgun barrel? What are the odds of getting it "right" vs. screwing it up? I have a lathe, mill, drill press, etc, but don't think I would use any of these for this project. I have reamed holes with the lathe and cut threads with both taps and dies by hand and with the lathe. I have also cut threads using the lathe.

I can rent a "20 Gauge Tru Choke Reamer & Tap set " from 4D Reamer Rentals for $50. I don't know if they charge extra if you plan to ream additional barrels.

Is there any advantage to the either Tru Choke vs the Win Choke style? Both reamer/tap sets are available and are the same price. The choke tubes look to be about the same price also at Brownells.

Thanks!
John

[tomme boy]

If I remember right, the true choke was meant for thin barrels. Like doubles and over unders. I had Colonial Arms do a gun for me and they said to go the True choke over the Win choke. Might look them up and give them a call.

[Mk42gunner]

I would do a lot of measuring of bore diameters and wall thickness before I ever even ordered the rental tooling. Also, I don't know about what thread is used for 20 gauge, but check on that too. If possible I would get whatever matches RemChokes for the 870 barrel. It may not matter to you right now; but if you ever have to sell the gun, something that will work with factory chokes will come closer to not selling for a loss.

I don't shoot a lot of shotgun shells anymore, but I am not that enamored with the screw in chokes. I have one shotgun with them and the same choke has been in the barrel for about seven years now. My preferred method of selecting chokes is two barrels and two triggers -- front trigger = modified choke, rear trigger = full choke.

Robert

[Hardcast416taylor]

About 30 yrs. back I had an 870 20 ga. and an 870 12 ga. converted to the tru-choke removable choke system. I acquired the 3 necessary chokes full, mod. and IC for each. I later got a skeet choke for each and a extra full choke for the 12 ga. I have had excellent results with them over the years. I was told the process isn`t that difficult to do if you have the right tools for boring and threading. Robert

[376Steyr]

The Brownells hard copy catalog has some very useful information on this topic, plus a complete selection of tools and choke tubes to look at and consider.

[Skipper]

I've used the Brownell's Colonial Arms adapter and it works well

http://www.brownells.com/gunsmith-tools-supplies/shotgun-tools/choke-adapters-gauges/screw-in-choke-adapter-prod7754.aspx

It takes Win-Choke style tubes, and it solders in place

[TXBRILL]

I would send to Mike Orlen in Mass. He does a great job is very reasonable and turns them right around. Go to www.shotgunworld.com and you can find his info and hundreds of positive comments about him and his work

[KCSO]

Al right first you need bore gauges and wall thickness gauge. The Remingtons especially have out of round bores with thin spots and yu need to measure where you want to cut the barrel. I personally prefer the Carlson's tru choke in the thinwall for the older remingtons. If you can get a brownell's catalog it will have the min dimensions for each choke listed. Then you need a reamer and the tap set for 20 gauge. If you don't have a lathe you can ream and tap by hand but a brace and bit set up for the choke tools makes the job a WHOLE lot easier. Tolls shouln't run more than about $250.00 and the chokes are about $10.00 each or... find someone who does them and have them done for $100 a gun or so.

[W.R.Buchanan]

Here's a REAL HOT TIP!

Send the guns to Briley. Google them, they make the best choke tubes and they also modify shotgun barrels to accept screw in chokes.

This is a job that is best left to those who do it everyday and the cost of the tooling alone is far in excess of what they charge to do the job right the first time.

There are times when you just need to farm the work out.

You can also go on www.trapshooters.com and ask for references for outfits that do this work. It is a common thing to do in the shotgun world.

Randy

[wv109323]

As mentioned the earlier Remington Barrels need to be measured to make sure they are thick enough to accept screw in chokes. I have no experience with Tru-choke but I don't care for the Win choke that extends beyond the muzzle. I had a sawed off Remington 870 Express converted to the Colonial system and am satisfied with it.

[garandsrus]

The tool rental is $50 and i can do several barrels. I dont plan to buy any tools.

I dont know, which is why I was asking, but I dont think a lathe is required with the reamers. I do have a lathe but dont think the barrels will fit through the headstock. I dont have a spider either to center the barrel, although i could make something. I can probably find someone with a larger lathe if needed.

I might have a Brownells catalog around, I will need to check. Thanks for the heads up. I did find a barrel spec sheet with similar information for a set of choke tubes, so I will review that also.

Thanks for the assistance! Any other comments would be welcome.

[skeet1]

I have a Browning Citori that had fixed chokes that I had converted to screw in type. The job was done by Carlson's in Kansas www.choketube.com/ The job was done very quickly and perfectly and the choke tubes are very thin to work in these barrels. I used this shotgun for shooting skeet for several years using skeet and skeet choke tubes. I also got a full, Mod. and I.C. a very nice set up. Would I do it again? Yes.

Ken

Ken

[W.R.Buchanan]

Ken: I forgot to mention Carlson's. They make good inexpensive Choke Tubes and they make some of them on a machine I made. they are well qualified to do the work and don't charge an arm and leg to do it'

My whole point of posting on this thread is to encourage others to send this work out to an outfit that does it every day.

IN the machine shop world, and gunsmithing is part of the machine shop world, it is best to do what you do best and farm out the rest to places where they commonly do what you need to do, that you don't commonly do.

It is not cost effective to do jobs that may only come around once in a long while, due to two major factors. One is tooling and the other is learning curve.

I'm not saying you shouldn't learn how to do more kinds of work, I am say "Why Bother!" It is enough to know that it is beyond your capabilities.

Now if you want to take on this type of work as another facet of your business, all you have to satisfy is, "can you get enough of this new work to justify taking it on in the first place?" Just being able to do it is not the only thing you have to look at from a business point of view.

I can do lots of things in my shop. However when it comes to specialized operations, I farm the work out because I lose money on things I can't do effectively.

I farm out Blanchard Grinding for parts that are not standard material dimensions to start. It is far easier, way more cost effective, and produces a better product, if I start machining on a part that is already ground to net overall dimensions, than if I spend the time to square up a bunch of parts on the mill,(which will look like ship) and then start machining them to final configuration. It is not even close.

I have a Heat Treating Furnace that I got when I was making knives. However I wouldn't even consider firing it up to heat treat parts that I can have done for $95 that will be certified when done, and be done better than I can do it. IE: they can do a better job than I can, and I actually know what I'm doing on this one.

I could, in my shop, thread a shotgun barrel and after I researched exactly what needs to be done for the specific gun I was doing,,, I could get it right the first time.

I couldn't do it for $50-60!

Randy

[Mk42gunner]

Well said, Randy.

Robert

[skeet1]

W.R.Buchanan,
I think you are exactly right This job should be done by someone that is qualified to do it. Carlson's did a great job for me and they do this sort of thing regularly and are good at it. I would think that it would be difficult for a small shop to compete.

Ken