.308 insert-barrel for 12GA Over/Under

[pilgrim]

Hello...
after a 2 months period of trying to sale my 12GA over/under, I desided to turn it in to the combo gun: .308/12GA....
is it possible to make an insert from used heavy barrel in .308 ???
where is the better position of .308 barrel: in the top or bottom barrel???
is it legal???
thanks a lot
best regards
Kot

 

[david doyle]

might want to compare 12 gauge pressures to .308 pressures. Maybe it can done but maybe not.

 

[tiriaq]

This has been done with lower pressure cartridges. I'd be a bit nervous about .308. Bottom barrel; less stress on action. How big are the firing pins? If they aren't small, that would have to be changed. Are the breech faces thick? Don't use a heavy barrel for the insert; use a lighter one, with a collar at the muzzle of the insert to fit the bore. There are all sorts of things that have to be worked out - locking the insert in place, sights, zeroing, extraction. What sort of accuracy would you expect? A good job would not be cheap. While possible, this might not be a practical project.

 

[juanvaldez]

Seen lots of inserts for pistol cartridges but not rifle-

 

[Casull]

There used to be a number of commercial adaptors to do this with common calibers. .308 was one that was made. There are a few things to consider but it's not big a deal. I have a number of these adaptors that I have made in a few combinations and they normally work quite well. Accuracy is alright though nothing like a target gun in my experience.
What make and model is your shotgun?
Normally the lower barrel is used because of it's lower centerline and therefore better for dealing with the thrust.
One of the Gun Digests and I forget the year has a great long article on this. They used to be relatively common and popular. There were and are some very high quality European adaptors but there were a few American makers that made more affordable adaptors. I will look for that article and see if I can tell you what edition it is in.
I have made a few in various calibers and for different gauge and and caliber combinations. They can be lots of fun. I think you could get a very good combination if you find the right guy to do it for you, it's not really that difficult a job.