Choke tubes, so confusing!!

Long story short, I want to assemble a single shot 12g for various purposes namely a "survival" shot gun. I've got an NEF. My plan is cut to 18.5/ thread for choke replace the wood with synthetic stock and side saddle, replace the foreend with synthetic. And add the tactical krylon finish.

Goals:
1. Ability to shoot slugs/ OO Buck for defensive purposes.( rifled or sabot slugs IDK.
I shoot shot rifled slugs in my mossberg 500 it doesn't accept chokes 18.5 in barrel 8 shot tube.)

2. Small game, birds, rabbits, squirrels etc

3. Breaching ( I know, I live a rich fantasy life but still want the capability)



What type/ style of chokes should I have it threaded for. It seem like Remington has a breaching tube readily available, then. I assume I need to thread for Remington. What type of chokes do I buy to accomplish the remainding goals.

I have looked for a dumbed down chart or explanation of what different chokes do and my google kung fu is weak. Any help would be appreciated. Even better a shopping list would be gold star sticker worthy.

Try reading through this link. It is very good basic choke tube info.

http://www.rem870.com/2012/05/06/sho...modified-full/

Before I got too excited about what choke does I would have the barrel looked at. It may not have enough wall thickness to safely thread for tubes. I wouldn't worry about screw in chokes for your application anyway. You don't want choke for buckshot/slugs and Cyl bore works fine for small game out 25-30 yards. Have you shot this gun yet? Calling it a "survival" gun is appropriate... Most people would prefer being shot by it over shooting it. If you don't have a flinch you will after a couple of shots with a lightweight 12 gauge.

Take a look at Federal FliteControl loads. If the barrel doesn't strip the wad, they will give most of the flexibility of screw in chokes for a given type of usage.

If that doesn't work, I use modified choke for most everything (3 gun bulk loads, buckshot, and slugs) except when using a turkey choke.

All chokes do is to reduce the size of the shot pattern at longer ranges. If you have no choke, you have cylinder. If you are going to be shooting things at relatively close range (sub 25 yards) then there is no real need to have a choke as the pattern is not so big that there are big holes in it big enough to miss smaller birds or animals. If I was building this gun, I would be planning to use it at short ranges and I would want it to be inexpensive and have minimal points of failure. If you shorten the barrel and leave it as a cylinder (so no choke), it will work fine for slugs and buck and will work for hunting and breaching (to the extent you are going to be breaching). Besides, changing chokes is a pain and most people put in one choke and very seldom change it.

Overthinking for sure. My brother who is a Remington certified armorer and has lugged an old 870 wing master in the wood since the early 1970's at one time got a slug ( the old smoothbore cylinder bore choked one ) barrel that had a bulge at the muzzle from being shot with an obstruction. He cut it off at 18.25" ( essentially no choke at all) and I lost track of the game he took with it birds bunnies deer etc

This is the place to source choke tubes.
http://www.choketube.com