Remington barrel choke thread kind of wrong

[red_bailey]

Like many of you here, if I stacked up all my Remington Model 870 shotguns and barrels, I'm pretty sure I could be accused of outfitting an army.

I picked up a new TruGlo Titan Adjustable extended ported choke (12ga. Rem is what we're talking about), why not. (Like this one ww w.cabelas.com/catalog/product.jsp?productId=742233)

The thing fits in my 18,5" Express barrel, screws in all the way on my 30" Super Magnum barrel, and so on. But it was actually my intention to put it on a 28" vent rib with 3" chamber, mostly because I have two of those here, also it seemed like a good match. Haven't gotten off to pattern it, though, because it won't fit in either one.

Going to screw it in, the threads catch and it goes okay for several turns, but then it starts meeting resistance until it binds completely just past half-way in. I started with clean and oiled threads, but I tried assembling it dry, cleaning it, different grease and lube, hot barrel and cold choke, just no go.

Just to confuse things, all of the barrels will work just fine with Remington's standard flush tubes, some extended chokes for turkey, rifled, tactical door breacher, whatever else I've got around.

No problems, my plan is changed to try it on the 30", but why?

Date codes on the sister barrels show late '80s and early '90s manufacture. Was there some slight difference at this time in the Rem-Choke system? I don't know if the binding is due to thread pitch (I suspect) or a slight difference in length or diameter of the reamed out area.

 

[3macs1]

I will take a stab at this. There was no threaded choke system in any remington barrels prior to late 85 so if you have some earlier they were done by a gunsmith and god knows what they used probally some form of a thin wall and god knows how deep they went.
Now in 85 remington did supply some barrels factory with threaded tubes but they were not remchokes they were briley tubes and a super rare square shaped thread which are impossible to find and have to be special made by briley. Then somewhere in 86 the 1st remo choke was put in but it really wasn't officially rolled out until 87. Then after that they supplied some with pro bore tubes just to make it more interesting.They were longer and threaded on the top not the bottom of the tube
I have barrels with all three factory types and thin walls but never tried to mix match them. I would say that is what you are seeing

 

[red_bailey]

I'm pretty sure the two 28" VR Mag barrels are threaded for Rem-Chokes. I mean they take all my factory flush choke tubes, and factory and third-party extended tubes; never had a problem with them until now. The date codes were 1989 and '92 if I recall (I suppose they are the oldest choked barrels I've got).

Not going to complain to Remington, the problem likely originates in the after-market choke; might get out the calipers and thread pitch gauge if it keeps eating away at me. Just a little baffled that the Titan fits my other threaded barrels, my other chokes fit all my threaded barrels, but the Titan won't fit the ones I wanted to use it on.

 

[3macs1]

I'm pretty sure the two 28" VR Mag barrels are threaded for Rem-Chokes. I mean they take all my factory flush choke tubes, and factory and third-party extended tubes; never had a problem with them until now. The date codes were 1989 and '92 if I recall (I suppose they are the oldest choked barrels I've got).

Not going to complain to Remington, the problem likely originates in the after-market choke; might get out the calipers and thread pitch gauge if it keeps eating away at me. Just a little baffled that the Titan fits my other threaded barrels, my other chokes fit all my threaded barrels, but the Titan won't fit the ones I wanted to use it on.

89 and 92 would be rem choke for sure if factory mag barrels.