• Mossberg Owners is in the process of upgrading the software. Please bear with us while we transition to the new look and new upgraded software.

Choke Tube Threading

MikeD

I'm Your Huckleberry
Staff member
Administrator
Global Moderator
"Philanthropist"
A slight diversion from my AR build to work on a small project.

After much internal debate I finally purchased the tools to thread barrels for choke tubes. I have several I want to do and the cost of tools is on par with the cost to get them all done so I opted to buy tools. :-D

rIxcQA1.jpg


The thread tap is on top and the reamer in on the bottom. The brass parts to the right are bushings. You need to use the largest bushing you can that still fits easily into the barrel, this is what keeps the tools in a straight line.

cbPxAKI.jpg


My high tech driver for the reamer. The tools have a 1/2" square shank so I had to engineer a tool to make it fit into my drill.

ByJp2ZA.jpg


I found that a 3/8" socket extension worked really well and that a 1/2" adapter fit the reamer perfectly.

F513ZTI.jpg


Reaming the barrel and almost done. It cuts in steps. the first step is where the threads are cut and the 2nd is the diameter of the choke tube. Cutting gets harder once you hit the second step as you are cutting two steps into the barrel.

6ySjpiw.jpg


You can see here the steps on the reamer and how the bushing attaches to the end.

DsrbHQR.jpg


Reaming complete and the steps are cut into the barrel. This actually took a LOT longer than I thought it would. I went as slow as I could without creating too much heat in the barrel. I probably could have gone faster but then I would have had to take periodic breaks to let stuff cool down so I suppose it's probably a wash, better slow and safe IMHO.

m6ox547.jpg


Tap for the threads ready to go. Note this is the same bushing I used on the reamer in the first stage.

3r4PJG1.jpg


nQ9szw1.jpg


I do not have a tap handle that fits this tool so I improvised.

d65tO9n.jpg


Threads cut. I ran the tap twice. Once for the initial cut, cleaned it off and ran it down again just to make sure I had clean threads.

VNd2GsR.jpg


Turkey choke tube.

K8w4S8u.jpg


Tube fits perfectly.

It's Miller Time!!!

Overall thoughts: The process takes a lot of time. I probably had 4 hours into the entire project. I also stopped and cleaned the reamer every few minutes. For some reason as I cut deeper and deeper, some small bumps developed along the cutting edge. I was probably not applying even pressure throughout the cutting process. As a final step at the end I oiled everything up good, set the drill on high and let it rip with very light pressure but increasing until the bumps were milled away. I ended up with very smooth lines on the steps.

Conclusion: I am extremely happy with the results.
 
Last edited:
This was a smooth bore barrel with cantilever scope mount I picked up a while back. It has a really cool brownish color to it like many old shotguns. I plan on using it for turkey hunting.

Well, I say that but I have so darn many turkey barrels and guns set up , I never know which will make it in the rotation each year. LOL
 
Nice job Mike! I think i would have went the same route you did if I had more barrels to do than just one.

I haven't had time to shoot my 20" that I had threaded , I am thinking it will be nice to run certain buckshot through the IMP/CYL choke.

And I agree that if a person had more than 2 barrels to do that you would pay for the tooling. Keep us posted on how it patterns after having her choked!
 
Looks Good! :) Could you have hand-reamed it? I'd hate to dull a reamer by overheating it... :eek:

How much were the tools, btw? I like your drive adapter--maybe grind three flats for the chuck jaws to bite into. I have a special tool I'd use instead of the vise-grips... ;)

lb2.jpg lb1.jpg
 
@Bobster The tools ran me close to $300 ( I did use a coupon at Brownells that took $30 off of my order). That was for the tap, reamer and bushings. I was not sure which one I needed and I am glad I bought a few because my measurements did not exactly correspond to the bushing I ended up using.

I think a hand drill would be the preferred method. I no longer have any of the old auger style hand drills and to buy one new they cost 3 times more than what I paid for my Ryobi Drill. I need to see if my dad if he still has any of my grandfathers old drills. One of the videos I found actually demonstrates the process using hand tools. There is a resale shop near my house I may check there as I know they also have a selection of old tools. I might be able to find a bargain. The old stuff lasts a lot longer than the newer stuff made of cheap metals. ;-D

I set the drill in the screw driver mode and ran it as slow as possible. I would check the barrel by hand to make sure it never got to hot. I never let it get hot enough such that it was too hot to touch. It would get warm but not hot. I was also stopping frequently to brush the metal shavings off of the tool with an old paintbrush and add some oil.

I think your La-Z-Boy handle would be perfect. I only used the vise grip for the threading process which required very little effort. I had very little slippage with the socket extension I fabricated into a bit. I think a swivel extension may be even better as it will allow a little more movement without torquing the barrel; but the bushing system works really well at keeping it centered.

This is the same tap that is used with RemChoke as well. That does require a different reamer to align the threads properly. I have pretty much duplicated my Remington chokes with Mossberg ones now so I think I will just use this setup for my 870 as well. It may only be an issue if I ever decide to sell any of the barrels but I don't see that happening any time soon.
 
Wow Mike.

I've threaded some stuff lately, but I would not have the brass balls to try it by hand on a barrel. Especially with as thin the wall is after you drilled it prior to making the threads.

I'm more impressed with this than I was when you completed your lower, and I was so excited about that I couldn't stand it.

I'm looking forward to seeing hot it patterns. Yes, I know that's not entirely indicative of the barrel and would change with the choke and shot size and all that's associated with that, but it looks great.

And here I was proud of myself when I threaded a barrel for a front sight bead :p
 
Thanks john. I admit I was worried. The barrel was barely large enough to install tubes. When I first started it didnt look lime there was going to be any wall wall left to hold the tube.

Seems like lately I have not been hesitant to just jump right in and try anything like this.
 
Talked to my dad and he still had a few of the old drills

DFlWAx5.jpg


Hit the mother load!!! Nothing like old hand tools to put a smile on your face.
 
Last edited:
I have used hand drills like both of those kinds.
 
A little history to them as well. The one in the center was my maternal grandfather's and the other two were my paternal grandfather's.
 
I was asked about this thread so I decided to fix the links so the pictures would display. Enjoy.
 
Thanks Mike.

Is there any way you could check the outside diameter of the barrel that you used, just for reference so we'll know if we ever come across a "thin" barrel that may not be suitable?

I suppose, you could also check the diameter of the thread tool too ???
 
That came out really nice. Great job!
 
Thanks Mike.

They came out better than I had hoped.

It should shoot a lot better now all around.

It's supposed to be pretty warm this Friday. I'd like to be able to go test them out with a handful of various shells and chokes.

The Mossberg barrel turned out well too. Though I'll need to move the bead back from where the factory installs them. I don't see how there would be enough threads to hold a bead. It's super thin in that area.

mossberg 500 thread 001.JPG
 
I had the same issue with the barrel I had threaded by Rose Action Sports before I bough the tools to do it my self.

I bought a Rem 870 tactical sight base that I had hoped would provide bit more for the threads to bite into and lift the bead a bit as I always shoot high with a short barred gun with a bead. The sight needs to be silver soldered on. Williams Gun Sight said they could do it but I have not followed up on it
 
I have the drill and tap to move it farther back, but I don't have any welding (brazing) equipment. Truth be told, I haven't brazed anything since high school shop class (yeah, it's been a while).

On the Mossberg, I may not even fool with putting a bead back on the barrel. I had planned to use a small red dot on it, like a bushnell trs25 so I can dial the pattern in perfectly. Or near perfectly (depending on what and how I'm shooting).

I am also really looking forward to trying out the Remington barrel. The meprolight (tall front) had slugs and buckshot hitting really close before. I'm excited to see how it shoots using the IC choke and where it patterns.
 
Back
Top