doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Sleeving a 16 down to 20 ?

It's just an idea for now but can a black powder proofed 16 on a scaled down action be sleeved with 20 bore tubes ?
I've read about chamber sleeving but the original Damascus tubes are out of proof, past their best and have been cut down to 27 inches so have no chokes.
I figured 20 bore nitro proofed barrels would be easier on the old action and if made to 27 inch would mean I could use the original ribs complete with their still sharp and clear engraving. I have no idea if it's do-able so thought here would be the best place to ask.
Cheers,
Nick.

Briley does 16 to 28 gauge
http://www.briley.com/c-418-fitted-tube-set-pricing.aspx

You can also check with Kirk Merrington

http://www.merringtongun.com

It would have to be a truly exception gun to be worth the cost

It may be do-able, depends on the gun. We have commissioned many 12 to 16's and several 20 to 28's but no 16 to 20's. The trick is finding someone happy to take on the issues of barrel alignment with the 16's breech centers but the 20's smaller muzzle diameters. Also the difference in OD of the barrel tubes at the point of joining. You will probably also have issues with forend wood fit with the smaller tubes and the loop may need altering to latch properly.
Keeping the same barrel length is not restricted by rib length as these can be extended be welding on a new section.
Price in the UK would probably be about 25% to 50% more expensive than same gauge sleeving.
You might need to have special tubes made if your 16 is unusually heavy in the joining area and this will further add to the cost.

Briley no longer offers sleeving services, only tube insert sets.

I have a gun that started life as a 20-gauge Lefever Arms Co. Durston Special that was sleeved with 28-gauge barrels. Parker Bros. built 20-gauge guns on 0-, 1- and 2-frames, so firing pin spacing shouldn't be an issue.

Uou might try 16/20 ga chamber inserts, they seem to give pretty good service.
Mike

Thanks for the replies everyone, I was hoping to have an invisible sleeve job done rather than inserts as the original barrels are honed out of proof and pitted, plus shortened so are just nice looking scrap tubes now.
I will do some measuring and consider if it's worth looking into.
Toby,I hadn't even thought about the fore end and see your point with the centres and presumably point of convergence.
The gun is a lovely old BLNE from Griffiths of Manchester with some really nice features and if it could be saved it'd end up living in my cabinet. I realise it would not be an economical fix but sometimes things catch your eye and you carry on regardless. I imagined the small action built for a B.P. gun may not be strong enough for nitro in the same bore and that's what started me thinking about going down a bore size. If it's not possible it'll end up as a wall hanger, it's far too pretty to scrap.

We used to do a lot of these and had specially profiled tubes made to a heavier profile to the backends . Standard 20 bore tubes may be OK if its a reasonably light weight gun ,needs to be measured up . As said you may need a new loop but will also need to have the extractors built up or new fitted . Most that we did turned out OK but there were some that really needed to be re-forended .AS to proof pressures you are still going to have high back pressure so its a matter of deciding if the action and lumps will stand it .

Dont have the up to date pressures to hand but think its the same for 16 as 20 .

I did this to an O-grade Parker hammergun in 16 gauge that had bad barrels. The pits were too deep to hone out. Brad Bachelder did the work. He rechambered the gun to 20 gauge and sleeved it invisibly with 32" steel tubes. Both barrels modified choke. Really fun gun.