Buckshot,I bet that is a typo error. The N-SSA does not require orgional type or style of rifleing to be approved.They require outside mesurments to be withen specs.ie barrel length,band,sight placement.Stock pull,drop,length. You can add hight to front sight or drill a peep in orgional sight leaf.Must have 3 lb trigger and half cock hold weight of gun. That is most of them. Most of the Italian repos have barrels that are oversized in barrel and breech diameter.By a bunch.Drop a orgional in a repop stock and you need a LOT of epoxie to filler er up. I should go measure up some and post the dffrence.

Some of custom barrel makers we use make faster twist and land numbers. I have a 7 grouve 1 in 54 1855 rifle with a 33" barrel. by Jerry Harmon He uses a Bill Large style rifling. Bobby Hoyt will make up any twist/dia. you want.I have had him reline 1/2 dozen barrels for me .44 up to a .69

Buckshot, Yup them "tubes" have lots of uses.They are just threded tube protection caps. I have them 36 to 69 calber size.They make them in bunch of colors that works well in keeping diffrent loads seprate.I had a couple loaded ones go through the washing machine.Minne was a littke beat up but the powder was dry.

 I just dont see why the slow twist gets such a bad rap.Granted a faster twist will be a bit better at less that 150 yards.But not that much.I have seen one hole groups at 50 with both twists.Just got to find the right minne combo. A new 16 year old pup on our team brought me his old Zolie Zouave last week. He had some ugly minnes [Rapine old style]he cast.Bore was a .581.boolets were .580.Did I say they were ugly minnes.Had voids,bad skirts etc.Anyway I lubed up 10 of the better? ones.used 45 gr ff. With a cruddy sights filed by previous owners I was not expecting much.That thing put 3 rounds into a clover leaf at 50 off the bench.Now it was foot high and 8" left.But thats is easly to fix.

Here is a link to one of the barrel makers I have used.He does regular C/W muskets and rifles http://www.edsmart.com/whitacre/ The other one is in PA. and does not have a web site.He has relined some weird ones  for me.A 44-40 rolling block,Sharps and Hankens,Uberty Henry.He has one of the old P&W sine bar machines.So any twist can be done.