I bought a 1187 Rem. Sportsman 20Ga with the short Rem. choke barrel. Trouble is I cannot get a Rem Choke to go into hole to screw it in. There is what I believe is a Mod choke tube in it and it is marked like this. M(0.5)Lead. This tube is very thin compared to Rem chokes. Does anyone know who made these tubes and if other chokes are available? Thanks in advance.

Briley down in Texas.

From your post it appears a previous owner had thin wall choke tubes installed. You will have to determine the tube threading to replace.

I just noticed there are 3 small notches in the end of the tube.

Maybe this will help: https://www.texasguntalk.com/attachments/choke_centik-gif.97789/

The three notches should mean modified choke.

The Briley thin walls I have had were not notched..not sure if that is true for all their thin walls. The choke was imprinted on the tube….Along with the choke Series.

In addition to the threading….the chokes have to match up with the barrel inside diameter. If not a choke could be ripped out of the barrel. Which usually will result in a reined barrel.

If the barrel had came with screw in chokes it would be marked so on the barrel.

I know basically nothing about Remington 1187 shotguns...could someone have put an older 1100 barrel made prior to screw on the gun ?

A good gunsmith should be able to tell what chokes you have....gunsmiths around here used to put thin wall Colonial chokes....there were a few makers besides Briley.

If you remove the choke tube is there writing on the tube to indicate mfr?

The only writing is this: M(0,5)
Lead

Still trying to research maker of this choke tube.

M(0,5)
Lead
This is how the tube is marked.

Any ideas?

Without a manufacturer name on the choke it would be a guess. Even more so with nothing more than a word description.

Are other choke’s available? Yes, send the barrel off to any of the ones who make them and they will make all you want.

M(0.5) lead is doubtful to give an accurate response. I have a friend who makes chokes on the side, and even he markes them with his name.

I have sat on Ebay this morning looking at pix of choke tubes. I now believe it is a TRU-CHOKE tube. Here is the first pix I saw thats looks to be the same tube that I have.

https://www.ebay.com/itm/184383755190?hash=item2aee20d3b6:g:EO0AAOSw~llcUeIS

I actually believe my barrel on the 1187 was cut off at 21" and the Tru-Choke system was installed. The end of barrel has no bluing. Everything looks very neatly done. I am going to buy one of the chokes listed there as Tru Choke and see if it screws into my barrel. If that works I will probably look into Carlson's tubes for turkey season.

There are a few things that may go wrong with your plan, especially when considering your barrel may have been cut off.

I would not be all that enthusiastic about being close to you when you are shooting.

Addition: Thin wall chokes perhaps will add another reason to be concerned.

battue-You have me worried. Care to explain?

Problem is you are guessing on a choke brand. A choke butts up against a ledge cut into the barrel and it is important the edge of the choke doesn’t protrude above the ledge. If so, as the wad and shot travel down the barrel they will catch on the edge of the choke. Which acts as a partial barrel obstruction.

The result can be a choke edge that will be bent into the barrel…or possibly blow thru the barrel end.

Most inside barrel diameters for chokes are measured at the end. If your barrel has been cut then the choke may have been special made for the diameter we’re it was cut.

The dimensions are even more critical for thin wall chokes.

And, I’ve have seen factory chokes out of spec for a particular shotgun be out of spec and rupture. Or perhaps they were not seated completely.

Best option, especially for a possibly cut barrel, is for someone like Briley to get it right.

battue-Thank you for that. hunter

Easy to google image pics of what can happen...

Buy a new factory barrel? Or a used barrel that isn't monkeyed with.

buddy had to send his choke to a choke manufacturer when he was in the same boat. I don't remember who he sent his to, but they were able to fix him up.
You may have to do the same

"... Yes, send the barrel off to any of the ones who make them and they will make all you want. ..."
...but you forgot to add, "for a small, nominal fee"! LOL!
I just checked the Briley site.
They will make a tube to fit any barrel.

When I had my shotgun barrel tubed, it was $300 and Briley furnished three (3) tubes.
They offer about a dozen different choke selections.
If you want more than the three tubes, extras run about $80 a pop.

More than likely a Tru-choke system installation. Colonial calls their equivalent TrueSize. Hastings also used to make "Tru-choke" pattern chokes. Both chokes below are Hastings.

The only other aftermarket choke installation I am aware of is Briley's system. Briley thinwall chokes have square threads on the muzzle end of the choke, and are generally longer than RemChokes.