13 gauge?
 

I recently posted pics of a 16ga scott hammergun I bought. I have liked it so much that when a reasonably priced "12" apeared on GB I hit the buy now button. The gun cleaned up real nice (see attached photo) but upon inspection of the proof marks it is marked to be a 13 gauge. 12 gauge shells fit nicely in the chambers so I assume it was bored with a smaller diameter than .729. I havent miced the barrels. but assumeing it is .71 or something are there any special concerns with shooting a gun with narrow bores. The water table indicates it was made for 3 1/4 drams and 1 1/8 oz.

No concerns, the chambers are 12 so the gun is a 12. The proof marks refer to the size of the bore, 13 markings in 12 is not at all uncommon.

Did you find that the barrel is marked "not for ball"?

Got to get my heart slowed down a little. First saw the post and thought it was a Parker 13g a Nice Gun Gary

My Thanks to both of you. It does not have the "Not for Ball" stamp which I believe indicates it doesnt have chokes The gun dates from the early 1870s by serial number. Which may have been before choked barrels were commonly used. Okay with me since I am mostly a skeet shooter.

I recently bought a English sxs 12 gauge fits chamber nice and both bores measure .690 I figured the bores were never finished great wall thickness and a beautiful gun ( I think ). This is a gun I was going to send to Brad B and see if it can be opened up safely for low pressure shells.

A British gun with unfinished bores would never have passed final proof and would not have been completed and sold.

Have an old gun checked out for safety, but openning it up to a modern 12 bore messurement is not required for safe shooting.

Can I shoot it with 690 bores ? If the gun is deemed safe , This will make my day !

Gary,
I'll bet you almost fell off the chair when you read the title of the post!
Jeff

Winplumber:
The ONLY way to know what your bores measure is to measure them. And even if they are .690 there is absolutely NO reason for concern if the barrels are in otherwise good shape. Just shoot the gun with low pressure/light load cartridges and enjoy it. You will never know the difference.
And... as someone else said, opening up the bores is counter productive... perhaps even dangerous.
The "13" is simply bore diameter as measured at final proof. However, honing over the years may have changed this measurement.

Best, Kensal

I would think so, you may want to use the fiber wad loads, that is what the gun would have been made for

I fire RST Lites in a 13 marked 12 bore on a regular basis