doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Re rifling shotgun tubes

Hi all,
I have got a H&H double rifle from 1891 that was sadly bored out to remove the rifling and become a 20G shotgun (blame the UK firearm laws).
But as the barrels are still very thick compared to normal shotgun tubes I was thinking it could be re-rifled for shooting 20G slugs.As a DR it looks to have had very little use over the yaears. Any ideas on who in the USA could do the woork?
I will be staying in California / Nevada for the next three months and bringing it with me.
Thanks, Martin

I assume you intend to have rifled liners installed in your now smooth bored tubes. I suggest you try John Taylor. He does many single shot rifle liners and might be willing to do a double.

http://johntaylormachine.com/38.0.html

Bavarianbrit,
A few of us here, well myself at least, would like to hear how you get on with this...please keep us posted...
It seems to me that as you are starting with a bore with a diameter of what the groove diameter was, cutting new grooves will make everything twice as big as the depth of groove..bigger in diameter.Will cutting new grooves in the bore make it too big for the intended 20 Gauge?
Perhaps with a longer bullet with gas check (?), it might Plump up to seal well.
I guess if that wouldn't work, you'd have to get someone to bore it out a bit to re line it with a rifled sleeve done to "Normal" 20 bore rifled specs?
Just armchair theory of course, but let us know.
Let me know if what I said was right , too, ok lads?
I'd love to find a heavy walled single shot to turn into a ball/bullet gun
cheers
franc

I have a NEF..H&R,(Wish it was H&H,lol) whatever single shot 20 bore rifled slug hunter.
Massive bbl wall thickness, even at the muzzle.
It was supposed to shoots Sabots,but I wanted old school so I slugged the bore back about a decade ago, n had a brass ball mold made by some guy in England.Very nice mold/mould too,by the way
I was never great with a Micrometer....I want to check my ball size...ok, no jokes here, lol...:)
Should my balls be the exact groove size?.
It used to do a clover leaf at 75 yds.....pretty target , but one Ugly gun..:)
cheers
franc

I do not want liners. I am an engineer and the wall are very thick and the piece is overheavy as a shotgun but it is still a nice looking H&H so I want to do as little more damage as possible.
The other alternative is to get the barrels reproduced as chopper lumps in .303 (to suit the vintage) but they quoted me around 5000 pounds in UK (Rigby).
Martin

Well, if you don't get liners, you are going to have to have the rifling cut with a broach. And since the bore is already nominal 20 gauge, you are going to need to use an oversized or hollow based Minnie Ball type projectile to get good rifling engagement. Assuming you have a typical chamber barrel arrangement, it should be possible, and the Minnie ball did work. It was undersized to allow muzzle loading and expanded to engage the rifling upon firing. I would think someone who re-cuts rifling might be able to help you out. Even though it is thick, I believe I would get a material Spectro anaysis to get a handle on the type of steel you are dealing with. Shouldn't be too expensive in that you could take it to them rather than have to pay for a field analysis. You should have access to this technology in Germany. Having a field test runs about $1,000 over here, and they can tell the difference between 304 and 316 stainless, so it's pretty accurate.
Good luck.

Maybe you could inquire at Delta Gun Shop to see if they might be able to help. Whatever you decide, you may be up against a time crunch if you are planning on taking it back home with you. Stories around here say you are probably facing reproof, is it worth trying out slugs at the range with the bore as is.

Most shops that do re-rifling use single point cutters and some form of Pratt and Whitney rifling machines. Broaches have been used for rifling, but mostly for military guns where only one caliber and twist justifies the expense of the broach. Button rifling is not suitable for contoured barrels because the rifling depth will vary as the wall thickness changes. I would think that a back bore of 0.010", except for the last 6" or so behind the muzzle would allow for a Paradox type rifling, and the bullet mold could be made to fit the back bore diameter. If the barrel walls are thick enough, that's the way I would go.

Have it fitted with rifled screw-in choke tubes?

Are the bbls heavy enough to allow rebore/rerifle to 16ga?.
If so that would allow you to cut them to what ever bore/groove specs you want for the type of slugs you anticipate using.

The current 20ga bores would probably work well rifled and shot with sabot type slugs,,but no guarantees.

Reboring and rerifling a set of SxS bbls is not on every rerifling-meisters task list.
Clearwater Reboring (Delta Gun shop) does it I believe. Can't think of any others off hand.

Turn over time is generally 5 or 6 months (and more) for most rebore specialists.
JES Rebore being the exception there, quick turn over,,,but I don't know that Jessie does shotgun bore rifling,,or work on SxS bbl sets.
You can check with him though. You never know what he's up too.
http://www.35caliber.com/