My brother has a Sauer drilling, 16 gauges over an 8 X 57 JRS. The rifle barrel is very corroded, probably from a lack of maintenance and corrosive primers. What can be done with this barrel to get the drilling back to usefulness?

1) just use it as a shotgun

2) give the rifle barrel a damn good clean and then a polish with JB paste. What is the crown like. You never know it may just shoot reasonably well and would give this try but take a careful look at the barrel once its clean for signs of pitting etc. may be work up a low pressure load with trail boss / lead bullets for use on small game.

3) have the bore /chamber recut to say 9.3 x74

4) have the rifle barrel drilled out and religned with 22rf /hornet

5) stick an Einsteclauf into the of the shot barrels.

6) or have a new rifle barrel fitted - but this will be expensive

If there is enough meat on the barrel wall I would have it rebored to 9x57 or 9.3x57 by these folks. http://deltagunshop.com/

If it is too thin to rebore I would firelap the heck out of it to reduce fouling, re-crown, and shoot it.

I had an old JP Sauer in the same conditon; I cleaned out the barrel and just shot it; it had enough rifling to hit a deer's lung at 50 yards. More importantly though, is for you to make sure your 16 ga chambers are 2 3/4ths and not 2 9/16ths which they probably are and might not be good to shoot modern ammo in. I reamed mine out to 2 3/4ths. On those old drillings the rifle barrels are usually quite thin for reboring.
OH, and make sure it really is a JRS and not a JR; you will have to use .318 bullets if it is not an S bore. (323)

Shotgun is 65mm, or 2 9/16ths, but the rifle barrel is definitely JRS. I think I'll try to get my brother to use the JB scrub method and see if it shoots OK.

I am in process of rehabbing a 303/12 bore cape gun. Bore looked awful, did lots of scrubbing, but still dark. It fouls due to pitting, but I just clean it often. I am looking into treatment with Dynabore Coat to fill the pitting and reduce fouling.

I have a .450 express 3 1/4" that has pitting throughout the inside of the bore; severe pitting. Many of the pits are pinhead size, and that deep. (1mm x 1mm deep). In addition to blackpowder and corrosive primers, it spent its life in the arctic shooting seals, so lots of salt water environment.

It shoots well enough to hit a 2 inch circle at 35 yards, where it regulates to. I use lead bullets with gas checks. And, the crown is awful to non-existent, I think it was cleaned a fair amount from the muzzle.

You might be surprised how a barrel shoots that looks rough.

dave

Re rough looking barrels: We were on a varmint shoot a few years ago and I brought my bore scope. Some of the rough-looking barrels shot quite well. I could draw some comparisons about the female of the species here, but will leave well enough alone.

Some of the roughest ones on the outside are the smoothest on the inside, and vice-versa. Oh, wait, they all eventually get rough on the inside. Not rifles.

As others have stated I would give it a really good cleaning with J&B Bore Paste.

Then I would see how it shoots, and how quickly it fouls. If it fouls badly, and accuracy goes bad after a few shots then I would look at getting some of the Moly aerosol spray for bullets, and give that a try.

Also if it does not shoot spitzer bullets good I would try some long for calibre roundnosed bullets, as with their longer bearing surface they might grip the worn rifling a bit better.

Indeed. I had a Colt 1911 one of the early 1915 ones with the half-moon backsight.

The barrel from the inside looked like the inside of a gutter pipe.

It shot ten round, into or all cutting a two inch bull, off hand, at twenty yards.