Winchokes not the same problem!

[Milkmaster]

I have a few Winchester 1300 shotguns in the cabinet of differing vintages and configurations. All of the "Winchoke's" up to now have always been interchangeable.

I found and purchased an extra barrel for a bargain recently that has the "Winchoke" logo on the side like the rest of my 1300's. The barrel has the familiar looking Winchoke screwed into it. I pulled out the choke, cleaned it, and tried it in ALL of my other 1300 guns. It screws in smoothly but lacks about 1/8" going in all the way. It does become tight and feels fine. I have compared it to my other Winchokes out of the gun. The height is the same, but the threads are about an 1/8" closer to the end of the choke. Obviously the difference is why it doesn't screw in all the way. This is not an aftermarket choke so now I am wondering...

Are all "Winchoke"'s not the same?

The absolute only difference I can find on the barrel from my others is the XTR logo. My research says this is an earlier 1300 barrel made when you could still get nice walnut and polished blueing on 1300's. The barrel does indeed look that way.

Please limit your responses to actual knowledge and/or experience.

 

[chas08]

Maybe you can find your answer here. My winchoke tubes interchange.
http://www.google.com/search?hl=en&...nge+chart&aq=1&aqi=g3g-v7&aql=&oq=choke+inter

 

[kirbythegunsmith]

Details

If the tube was from an era that had deeper threads cut into the choke hole, that could account for the difference in thread start position. A running design change of construction could have a few tubes that are identically marked be slightly different in the actual fit tolerances.

It is a natural possibility for any parts manufactured by mass production to have an interchangeability issue; whether by intent or accident, this can work most times but fail occasionally.

The problem arises more often when different makers use some generic measurements of sample parts to develop their own peculiar tolerances for that specific part- especially if they decide that several similar parts are (in their minds) actually identical.
If the tolerances are loose enough, it is possible to make a fit that is sloppy to go into any of the typical "interchange" holes, but there never was (apparently) an industry standard for those tubes usually classified as the same. There may have been minor variations in the depth of the hole, length of the thread or exit point of the thread on the tube, and so forth.

There are also the variations due to era of manufacture or sub-contractor error that would mean little difference in almost all cases, but if your specific problem was instead due to a minor depth variation of the threads cut into the barrels (perhaps a change in the tap cut depth or leade angle from plug to taper), then a problem that doesn't exist for other barrels could be a problem for one particular barrel (or tube, in this case if the particulars were reversed).

Kirby
[email protected]

 

[Milkmaster]

Maybe I did not explain the problem correctly Kirby. The threads do not jam. The two chokes are not identical. I have never ran into this before when dealing with 1300 Winchokes. I just wonder if the chokes were not the same on the XTR barrels. The threads are at a different place on the choke is why it doesn't screw in all the way. Take a look at the picture. Something new happens to me just every once in a while

 

[kirbythegunsmith]

Details

If you say that the one tube fails to reach the bottom of the hole, then some part of the tube must have interference.
You notice that the thread is closer to the skirt edge for the tube in question, so I would conclude that it is the thread that is running out of space in the choke hole.
You may not call that a jam, but it is the next best thing- a semi-wedge: gets tight, but still backs out OK.



See that the center tube looks like your over-long thread tube. The next one to the right looks like the longer relief thread tube you pictured.

Did you notice that both examples of yours and mine have the same variation of knurling, with the coarse cut being on the longer thread tube, and the finer knurl on the longer relief thread tube.
The second from the right flush-fit tube is I believe a Weatherby, and has a longer thread relief skirt.

Notice that the flush-fit tubes at the far right and third from the left have similar thread relief of the coarse knurl Winchoke. Those are Browning tubes, so now you see why I mentioned the apparent similarity not being the same as identical in factory spec.

The far left choke is one I made to fit a hole I installed a couple of decades ago, and because I cut the thread to the maximum depth in the choke hole, that tube can fit into a tube hole that I installed, but probably not many factory installed choke holes.

Is that a sufficient explanation of thread variation and fit?

Kirby
[email protected]