Home Forums Reloading 16 Gauge Society Gonna threading a 16 ga barrel for screw-in choke

Good evening guys. I have decided to throw caution to the wind and try to thread this old barrel for screw in chokes. If nothing else, will serve as my wintertime project, though, I think I can do this without too many issues.

As you guys are well aware, the dilemma is the lack of reamers and taps and chokes for the 16 gauge. You can find them all day long for 20 gauge and 12 gauge, but there's no love for the old 16 anywhere.

I've seen a few companies offering threading services, but the prices are more than the old gun is worth, so I'm going to try to do this myself. I'm generally handy with tools and have enough experience with metalworking tools and lathes to get myself into trouble.

The gun is an old Noble model 60. Specifically, a Montgomery wards xmh something or another. I only gave $95 for the gun after it sat all the way at the end of the gun rack in the back corner for months. The gun is good, and has a lot of the same design that you find on mossbergs and old winchesters and 100% steel parts even including the trigger guard, but having been out of business for 3+ decades, simply don't have the following or demand as some of the other names. So, I got a good deal on it.

Getting back on subject though, I have threaded multiple 12 ga barrels, so I have a working knowledge of how it works. I'm going to try to use a 20 ga REMCHOKE tap after waiting in line for my turn (4d told me it may be a couple more weeks before they could ship it because there are a few others who have already paid to rent the tool in front of me, so it may be the end of Jan or early Feb before I can complete the project).

But, in the meantime, there's a few things that I can do while I wait.

First, cutting off that dang adjustable vari-choke pineapple off of the end of the barrel. Seriously, I hated that thing. There was nothing that I liked about it. It was big and bulky. And what's worse, regardless of how tight or loose you cranked it down, the patterns essentially just shot the same regardless. Only thing that happened is when it was tighter, would snag more plastic wadding and make a bigger mess inside of there.

So, not much made me happier than to cut that barrel down and eliminate the old variable choke hanging off the end of it.



At least now the profile looks right. I didn't want to cut it to the 18 inch minimum, but still wanted something short that I can use in the woods too without being cumbersome and long while going through brush and briar thickets, so I chose to cut it at 22 inches.



Next up, measuring to see how tall of a front sight I was going to need. Considering the taper of the barrel and the old bead mounted atop the old pineapple, very tall. Taller than anything I could find online to get the bead up even with the top of the receiver so I could see and use it.

I chose to do an old school front ramp, similar to what you would find on a rifle or even kind of 870'ish riser. While not exactly proper for this gun, I used a CVA muzzleloading front sight that a friend of mine offered up for the project. I still had to shorten the height of of a little bit, but that was easy enough. I didn't even use the mill. I simply used my bench sander.

I also made a makeshift front sight for the time being using a #6-48 bolt, which I drilled through and put a green fiber optic sight. While I may end up buying a commercial fiber bead for it, this one is serving the purpose just fine.



OK, now to get back to the choke. I'm sure several of you were either shaking or scratching your head earlier when I said I was going to try to use a 20 ga remchoke in it.

I am.

There's a few reasons why. For starters, the outside diameter of that specific brand (remington) choke is .702" (upwards of .705"). That is well larger than the 16 bore and gives adequate thread and clearance into the barrel itself.

Secondly, the inside diameter of a 20 ga remchoke cylinder choke is .620". (mine was .620" on the dot).

A 16 gauge full choke, just so happens to turn out to be .624" diameter.

So, while 4 thousandths of an inch smaller is going to be considered an xfull bore I guess if you want to get technical about it, reality is, the two diameters are so close to each other that I think they will essentially perform exactly the same. There's often more variance than that just between different brand of chokes.

The biggest thing that I will need to do to the 20 ga choke is to taper the mouth of a choke where the wad/shot enters into it more.

I am going to achieve that with an MT2 Morse taper reamer. If you're not aware, all screw in shotgun chokes have a taper. They have to, otherwise the smaller diameter would snag the wads and cause bulging and blowouts. So, I will need to further open up the mouth of the choke a little more but that will be the last step of the process altogether.

Here, if you look close inside of this choke, you can clearly see where the taper stops.



Here is a pic of the tool that I will be using to do that step.



The only other thing left I can do in the meantime while I'm waiting is make my custom barrel bushing for the reamer/tap tool. Since it has to be a precise fit for the barrel itself, obviously I can't use the 20 ga bushings that comes with the tool rental. So, I lathed a piece of brass to the proper diameter of the bore. The last multiple passes are always the most stressful because it really does need to be precise and I'm very OCD when it comes to that. It has to fit inside of the barrel with virtually no slop, but not so tight that it's a press fit either. That would be equally as bad. I will need to drill out the center of the bushing once I get the cutter tools in hand, but again, that too has to be a really precise cut. Any slop there, would be just as detrimental as it would be if the outside was too far off.

I just love freshly turned metal. Always so shiny and untarnished. It'll look completely different a year from now once it ages and gets some patina on it.


And a quick pic of the bushing inside of the barrel.


I went ahead and started the topic in case anyone else is interested in following along. Or has already went down this path prior to me that may have some advice that I'm overlooking.