Feesible double 45-70

[DonT]

Had an idea floating around for some time now but not sure if it is feesable or note..

Does anyone know, or seen the following done:

Convert a 12ga SXS to a 45-70 double rifle by shortening the barrels to 18-20 inches and inserting 45-70 rifle barrels inside the shotgun barrles like you would a rifle barrel liner using acraglass to hold in place?

I know someone was building a 12ga coach gun with slide in inserts but i wanted something with some heft :grin:

I know there are issues with regulation of the impact points on both barrels but figured some of this could be accomplished at the time of assembly by bore sighting each barrel at 50yds after inserting in the shotgun tubes then clamping till the acraglass set.

thanks..

DonT

[bgjohn]

Somebody makes one already. I think I saw it in Cabela's catalog.
JM

[clodbuster]

Don T    Why quit with 45-70?  Go 50-110  Yeah!!!!  I know someone who did it with  a nice old  LC Smith.   Welded in liners  Regulating the barrels was the hardest part.  Shot like a muthuh

[gunnut69]

Be carefull what shotgun you use.  I've an Ithaca Flues model in the shop now with a cracked frame.  That was just modern heavyload shotshells.  45-70 even with factory loaded ammo generates more pressure than shotshells...  Better safe than sorry!!

[DonT]

Thanks for the input folks... Gonna give it a bit more thought.. If Baikal would come out with one of their O/U in 45/70 it would be the clear deal or maybe a 45/70 over a 12 ga. ;-)

Again thanks for the food for thought....

DonT

[Hooker]

I got a friend that put together a kit from Pedersoli it looked pretty good.
I'll have to ask him how it turn out. I beleive he said it cost about $400.00

Pat

[sgtt]

I have one of the coach guns with the inserts.  PLENTY of heft.  Regulation was a problem.  If I were to do it over I would go with the double trigger mdl.  I load to trapdoor pressures.  It will be in the woods this yr.

[John Traveler]

I'd heed gun nut69's advice, fellas!

Many of the older double shotgun frames are made from relatively mild cast steel or even cast iron with thin breech faces.  Firing pin fit can be sloppy too.

I've seen a home-made conversion to .223 remington (GASP!!) on a double gun frame using barrel sleeves, and that one left the owner with a neat .38 caliber sized hole in the breech face after firing a few rounds.

Please remember that even loaded-down .45-70 chamber pressures match or exceed 12 gauge PROOF pressures.

Please note that moder double rifles are built with heat treated steels and have extra thick breech faces and closely fitted firing pins.

[turfman]

I've been wanting a big bore double for some time now but can't justify the price tags of them. Baikal was supposed to bring out a double rifle this fall but it looks like it will be spring at best. They are supposedly chambered for the 45/70 and sell them for around $600-700. They say they are hung up in paperwork; but at the NRA show I come to find out that they need to fill an order for Savage for the receivers first.

Another option is to get one of the H&R ultra slug guns in 20ga and turn it into a .600NE. Ive heard of a couple guys do this with no problems at all.

turfman

[Judson]

It is indeed possible and safe to build a double rifle on a shot gun action.    Most American shotguns are too weak and lack one or more of the needed features for a strong double rifle.    You need an action which has a third fastener such as a Greener cross bolt or a hidden fastener.  
   As for the pressure you can figure out the pressures,and weather the exceed the original proof load by finding the head area of the cartridge you want, and comparing it to the head area of the original chambering.
In any case you will probably have to bush the firing pins and for get the sleeving idea, use the mono block and build new barrels from there.
   However you do it if you value your life RE PROOF the gun!!!!!
There is a very good book on building double rifles on shotgun actions and this is   Building DOUBLE RIFLES On Shotgun Actions by W. Ellis Brown.     It is not cheep, something like $49.00 but well worth the money.