12 or 11 bore?

[Eterry]

I recently bought a 12 bore double. The seller stated he'd had the barrels ultrasound for integrity. The muzzles mic at .750" and are 30".
Is it a 12 or 11 bore? She carries Belgium proofs, but not much else is visible.
Very nice wood, but the forend has a few splinters I believe can be easily repaired. The nipples are bad, beat down from decades of dry firing. I had them soaking in ATF. The locks are strong as per the period, both hammers have some slack and need shimmimg.
I bought this for my niece, but she's in love with my William Moore. I may have to break her heart.
Pics to follow..

 

[tenngun]

.75 is just about eleven gage and a bit
Howsomever if you shot a ball in it you would likely shoot a 12 (.725) in the gun

 

[Rock Home Isle]

The Brown Bess is a .750 calibre, 11 gauge…

 

[Eterry]

 

[Eterry]

I know it isn't a Bespoke gun, but I think it's a ways from what W.W. Greener called a Sham Damn gun.

 

[SDSmlf]

The muzzles mic at .750" and are 30".
Is it a 12 or 11 bore?

Call if whatever you want, but a .750” bore is pretty much nominal for 11 gauge. I forget the exact bore diameters on my Pedersoli 12 gauge double (they are slightly choked), but I know I use 13 gauge wads and cards when using purchased components (Mike’s Quality Black Powder Shotgun Wads if I recall correctly, a great place to deal with).

Basically, don’t worry about the ‘gauge’, just measure and size components accordingly.

 

[Eterry]

Call if whatever you want, but a .750” bore is pretty much nominal for 11 gauge. I forget the exact bore diameters on my Pedersoli 12 gauge double (they are slightly choked), but I know I use 13 gauge wads and cards when using purchased components (Mike’s Quality Black Powder Shotgun Wads if I recall correctly, a great place to deal with).

Basically, don’t worry about the ‘gauge’, just measure and size components accordingly.

Well, I have a 10, 12, 14, 16, and a 20. Now I have an 11 to fill in the blank.
IIRC, VM Starr's favorite gun, Sue Betsy, was an 11 bore.

I've been buying from Mike's since my first smoothbore. Great guy, great products.