Permanent Drop-In Insert

[Good Cheer]

You know the drop-in type inserts to adapt a break over shot gun to a smaller caliber, is it legal to make one permanent?
Was wondering about doing that and sticking a scope on it.

[Boolit_Head]

I see no need to make one permanent to stick a scope on it? If you have not tried them you may want to first. I have not heard good things about them.

[Good Cheer]

After I asked the question I realized that yeah, it's legal. The last three days of coughing and no sleep kinda dulls the brain.
What I was thinking on was fitting an insert and permanently installing it just like a barrel liner. In other words really nothing other than a barrel liner to fit a break over shotgun.
So I got about three more steps down the hall and turned the corner and then came face to face with duh, if the shotgun tube is longer than the insert then it would probably be considered an unlicensed sound reduction device.
Don't reckon I be's needin' any that. But apparently I could use a day off and some sleep.

[adcoch1]

The fuul length rifled inserts would be best, silver soldered in place to keep point of impact the same. I am thinking about doing this with a 44 barrel I have laying around...

[GhostHawk]

If your going to do it make it as long as you can afford.

Forget the 3" ones. They will shoot the shell yes. I have yet to see the short ones do better than minute of 5 gallon bucket at 25 yards.

The good ones, 11 inch or more seem to all have an o ring or two to seal barrel and keep insert in place.

I have been considering .45 acp for my single shot 20 ga. Or perhaps .45lc.

Either would send a lead slug downrange fast enough to go beyond the 50 yard semi accurate slug option.

[footpetaljones]

Make sure your receiver can handle the thrust of whatever cartridge the insert is chambered in.

[Polar_Hunter]

I have done one using an old 12 gauge single and a .577 Snider barrel. Barrel turned to a close fit and sealed inside the 12 gauge with permanent Lock-Tite. I re-chambered for a custom cartridge that I call .577 Long. I still haven't gotten around to going any serious load development but it is on the to-do list when the warm weather arrives.

https://www.youtube.com/watch?v=pJ0izgVrwbQ

[LAGS]

If the liner is permanent affixed inside the barrel and it is rifled it has to be 16" or 18" if smooth bore.
The liner when soldered or glued in becomes the barrel.

[Ballistics in Scotland]

The fuul length rifled inserts would be best, silver soldered in place to keep point of impact the same. I am thinking about doing this with a 44 barrel I have laying around...

I don't believe you are likely to shoot enough moderate-pressure rounds to get the assembly hotter than soft solder, epoxy or the bearing-fit versions of Loctite will stand. Silver solder, unless you mean the lead-free plumber's solders with a very low solder content, is less likely to provide total penetration all the way round and for the full length of the tube. Not that it is likely to be deficient in strength, but any gaps may produce uneven heating and expansion of the barrel. Some of the extractor or ejector parts, which must stay hardened, may be difficult to remove, and there is no chance of annealing them with the epoxy or Loctite.

One way this issue relates closely to scoping the rifle is that if it is really sure to be permanent, you can drill all the way into the shotgun barrel for the scope mounts, and thread them before the liner goes in. The .577 liner might be a bit thin for this, but not most of the others. I'd much prefer the liner to come right to the muzzle, with an invisible joint. But for this you should calculate the weight and put that much weight halfway down the shotgun barrel, to see if you like the feel of it.

[adcoch1]

I am going back and forth on the silver solder vs epoxy method, or weather to just stub the shotgun barrel and thread in the rifle blank. Set screwing into the threads to also hold on the scope base works perfectly IF i want to leave it scoped forever. But that is still an IF...
Any liner that is permanently attached can be shorter than full barrel length just like the drop in liners, but make sure that the barrel ( original shotgun barrel) is at least 18" to comply as a title 1 firearm. Its ok to shorten a long barrel if you want, but if it was originally a shotgun a minimum 18" and a minimum of 26" overall length must be maintained.

[John Taylor]

You don't need silver solder. I have been installing liners for 18 years and use 262 loctite. You do need a close fit, I try for .002" clearance. Better than a liner would be to cut the barrel and thread it for a new barrel. The liners are made from 4130 steel and new barrels are made from 4140 which is a little harder and may last longer with j boolets. Liner in a shotgun barrel may need a sleeve around the liner to fill the shotgun chamber. You can use a liner that is 1/2" OD in a 12 gauge with a chamber sleeve and a couple short sleeves to support it in the bore. If you choose to go this way the chamber sleeve should be soft soldered to the liner ( I use brownells high force 44, no lead.). I have had a few 410 barrel warp when reaming them to liner diamter. Not a good idea to turn down a liner to fit a 410. Sometimes I just make a whole new barrel and lug, this way you still can use the shotgun.

[KCSO]

I need to read the bottom line first! I scroll down and formulate and answer and then WHAM John gets there first. What he said!

[Ballistics in Scotland]

There is a lot to be said for drilling or reaming out the shotgun barrel to a diameter about the same as the rear of the chamber, and cutting it off at a point where it has become very thin. A 7/8in. liner from www.trackofthewolf.com or TJ's is available, described as being for the Colt SAA, and in most shotguns the end of the outer barrel can be concealed with a rear sight band or sling swivel band. Although the question of how you line an SAA barrel with that is somewhat complex, the job isn't. You might someday want to be ready to say you removed the front end of the outer barrel after attaching the inner one, rather than spent an hour or so with a sawn-off shotgun.

[John Taylor]

Green mountain has some new barrels that are less money than a liner. If a lathe is available then cutting off the shotgun barrel and threading in a rifle barrel is the way to go. When contoured it can be matched to the old barrel and when polished the joint can not be seen. The one draw back is the forearm hanger. A while back I cut off the shotgun barrel leaving it long enough so the hanger was still there. I turned down the rifle barrel to have a slip fit in the bore and made a threaded nut that filled the chamber. When it was all assembled and polished the joint was invisible. I did use plenty of Loctite so it would not move and the extractor cut was made after the parts were assembled.