OK.. got into muzzle loading.  ML shotguns are expensive.  Short Lane adapter and pawn shop single shot is cheap :)


That said.... 28" full choke barrel, muzzle measures .689 on inside, and of course my over powder cards, over shot wads, etc. are all .72"-ish, which makes actually getting the thing properly loaded somewhat of a bear (over powder cards not seating properly and over shot fiber wads breaking up on insert).

So.. I need/want to trim my barrel.  Question is, is how much to snip the tip to get rid of the choke AND retain as much barrel length as possible? (so no "just cut it to 20" and be done!")

Obviously I could trim silly small amounts (1/2"? 1"?) and check after each cut... but if 4" will get most of it I'd be happy to start there too :)

If you consider how long most choke tube threaded inserts are, you can probably remove about that much and be good.

There is somewhat of a forcing cone in front of the chamber on some barrels, so that might be some of your issue.

Last couple inches of the bbl.  Standard 12 gauge bore diameter is nominally 0.729 although it can be all over the map.

Jury rig a wall thickness gauge and trace it out.

Wall thickness gauge

It will varry between manufactures and barrels.  I know you stated you didn't want to necessarily do this, but if I wanted to keep the longest possible length while removing all the choke, I'd cut an inch at a time and measure internal diameter as I go.  .729" should be nominal as already stated.  Then re-crown once you've removed all the choke.

Not sure I see the practical application of this project.  How do you plan to use the black powder shotgun?  Would a side by side coach gun be a better platform to start with?

the choak is usually the last 3 inches.

I'd send it to someone like Mike Orlen and have the choked reamed out to what you want.

If you're shooting shot, some choke is better than cylinder bore.  Open it up to skeet  (0.005 constriction)

Practical? Well, inexpensive at least... considering a real BP shotgun runs $600+ ...   Anyway, planning for Fall muzzle loader small game and turkey season.  For some reason I don't think there would be much left if I used my .54 rifle... and I can't hit reliably enough past 10 yards with my 1858 revolver..



Eh, if a little choke is left and I can still get my over-powder cards and over-shot wads down without drastic measures I'll be fine.  If it ends up being a straight .729" tube that wouldn't be bad either - the "magic" Sky Chief loading method produces very nice patterns out of true smoothbore flintlocks etc.