« Reply #149 on: June 18, 2012, 06:25:28 AM »
When I was working on my suppressed 20 gauge barrel for my handi-rifle, I noticed in my junk pile an old Marlin .30-30 barrel. I cut it off at 15 inch +/-.. The length wasn't important because the barrel by itself is not a firearm and it would be inserted in a longer shotgun barrel meeting legal requirements. I turned down the re-crowned muzzle end to have about a one inch long OD to just slip into the 20 gauge barrel. I turned the chamber end to the ID +/- of a three-inch 20 gauge chamber. For an extractor/ejector I use a cleaning rod. No attempt for accuracy; I just wanted to see if I could make it work. I think it would work for any cartridge not exceeding the pressure limitations of the late Handi-rifle actions.
Now if I can find an inexpensive -- not likely, huh -- break action that will handle the .50 BMG. With a large suppressor, I might it get down to unsuppressed .308 level, but it would still be a bitch to shoot. But it would make a hell of a Hog Gun.
I have got a couple of these "liner" guns. One is a GM 45 ACP blank inside a Parnder 20 ga, finished at 18.5". Liner barrel is epoxied in place and the gun will shoot close to MOA @ 100. The second one isn't completed but has a shortened 30-06 chamber using formed 445 SM brass and has case capacity almost identical to a 7.62x39. This liner barrel is inside a 12 ga pardner barrel and currently is removable, but that may change. I havent' shot it for groups yet as it took a bunch of fiddlin' around to get the forming down on the 445SM brass. It will stablize a 190 grain BTHP down at 835 FPS.
One problem i see with leaving the liner barrel removeable is getting it fully seated into the shotgun barrel each time. A little dirt or oil etc. and your gun isn't going to lockup tight. This is assuming you headspace the gun on the breech end of the liner barrel and not the host shotgun barrel.
One other issue is you have to turn down the chamber swell on a donor barrel so one needs to think about what cartridge you plan on using and how you plan on doing your load workup. Removing a few tenths off the outside of the chamber swell of 7mm Rem Mag and putting it in a shotgun barrel you are more likely to be building a pipe bomb than a rifle. If you cutdown the rifle chamber and form a relatively small capacity "wildcat" and think about what and how you reload then things should go well.
I also think using a 12 ga host barrel is better because you will have more meat left on your liner barrel and less time spent turning your liner to fit.
BB
Logged
RIP Tom: Tom Nolan, ( bikerbeans) passed away this afternoon (02-04-2021).
Why be difficult, when with a little extra effort you can be impossible?
Wife's Handis; 300 BLKOUT
MINE: 270W, 308x444, 44 Bodeen, 410 shorty rifled slug gun, 445 SuperMag Shikari, 45 ACP shorty, 45-70 Shikari, 45 Cal Smokeless MZ, 50cal 24" SS Sidekick, 50 cal 24" Huntsman, 50 cal 26" Huntsman, 50 cal 26" Sidekick, 50-70 Govt Shikari, Tracker II 20 ga shorty, 20 ga VR Pardner, 20ga USH, 12ga VR NWTF, 12ga Tracker II shorty WITHOUT scope, 12ga USH, 10 ga Pardner Smoothbore slug gun & 24ga Profino Custom rifled slug gun.