doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Feasibility of Chamber Sleeving

Is it feasible to chamber sleeve a 12 ga barrel set to restore one that was proofed as 2 1/2" chambers but opened to 3"? Just the facts, please. No need to get into discussion about why it was done (I have no idea) nor the fact that it will still be out of proof (everybody knows that). Thanks.

Yes.
Depending...
Merrington does it.
But you may need a background check...

Get it evaluated by a good smith like Merrington or Kearcher to determine if you need to actually do anything other than fire loads that do not exceed the pressures for 2.5 inch shells.

Depending on how much wall thickness remains you may not have an issue.

If it is determined there is not an issue then go ahead and ensure the case clearly note 2.5 inch low pressure and consider stamping it on the gun and go on and shoot low pressure 2.75 through it without much worry.

Then again if the evaluation comes back the walls are now dangerously then either of those two listed above could further drill it out and put the correct sleeve in.

or shoot lite loads...

Yes, this should be do-able Gil.

Gil, are you trying to restore just the material that was removed when the chambers were punched from 2 1/2 to 3 inches? Usually, when I think of chamber sleeving, the goal is to reduce chamber size. For example, in order to shoot 12ga shells in a 10ga gun.

L. Brown, there was a nice article in Shooting Sportsman some time back about a gentleman who pioneered that type of sleeving getting it accepted by the British proofing system as I recall.

In some of Dan Lefever's writings, one of his early catalogs as I recall, he mentioned that when he converted muzzle loaders to breech loaders he bored out the threads for the breech plugs & sleeved them for the new chamber, which according to him resulted in greater strength than cutting off the threaded portion as that would have left the chambers thinner. I don't know if he was the "Pioneer" of this "chamber sleeving" or not, but seriously doubt he had anything to do with the British Proof House accepting it.

I thought I could easily find the article I remember but a scan of indexes didn't come up with anything that struck a cord. This was an article in the past few years. Maybe someday (as is usual) I will stumble into it again while looking for something else. Perhaps I should have used the term advocate rather than pioneer.

Gil,

I had a 10 ga 2 7/8 chamber sleeved to a 2 3/4 12 ga, and a 24 ga sleeved to 28 ga and they work great.
If your gun was mine and the barrel thickness was ok ahead of the 2 3/4 area of the chamber, I would just shoot it and call it a long forcing cone.