doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com What ammunition is a .725 bore 12 designed for?

Was the thought that the gun would use ammunition with felt wads? I'm thinking felt wads would seal up a little better with that tight a bore.
I'm pretty sure plastic shot cups aren't the hot ticket with a gun so bored, just from studying the pattern boards with their use.
Anybody care to weigh in? Gun is a Spanish Uggy, nice enough old piece (1972) but, not old enough for the maker to discount the use of shot cup ammunition.

Thanks in advance,


Best,
Ted

I would also make that assumption but a lot of European guns are still made with those diameters perhaps manufactures believe a tighter barrel works better for some reason

Ted, not sure if that .004 would make that much difference to .729. I have a Zabala Derby (American Arms), the bores are .718 right barrel and .722 left barrel both 15" from muzzle. These barrels are 26" 3" chambers. Choke code is 18.4 ****(.004) for right barrel and 18.5 *** (.012)left barrel.
I bought another set and fit them, they are 27 1/2" and the bores are .717 right and .716 left, and would be mod/full

I'm guessing it is from around the same as yours.
On the receiver is 1360 GMOS=2,998 psi.

Haven't shot mine yet.

.005 probably doesn't make much difference, but, not much is made with a .729 bore anymore-seems like .736 is all the rage.
I was just curious as to why the tight bore from standard in, of all things, a 3" chamber gun?

Best,
Ted

Bore diameters are all over the place, and does it really make any difference? Point where the bird/target is going to be and they die/break.

The tightest bores I've measured are on my Fox Gun Co., Balto., MD., U.S.A. doubles. Both are twist barrel A-Grades and both were chambered for the longest 12-gauge shells available in those days, 3 1/4 inchers!! Serial number 153 has a bore of .712" in the right barrel and .708" in the left barrel. Serial number 714 has a bore of .713" in the right barrel and .710" in the left. The biggest 12-gauge bores I've measured are on Parker Bros. doubles from the late 1880s/early 1890s where .750" to .757" are common. I've been shooting Pheasants for 45 seasons with a 1914-vintage Ansley H. Fox A-Grade with bores of .724". I've got two Remington Model 31 TCs and they both sport bores of .744" while my other Model 31s have bores in the .728"-.730" range.

A few years ago many Trap shooters believed the Stan Baker "Big Bore" barrel would get them an extra target or two, and it was a .800" chamber all the way to the choke!

My Perazzi MX8 and MT6 both had bores of .720, FWIW
Mike

12 gauge.

When I was doing some gunsmithing, and measured a lot of bores, I found great consistency of bore size within brands, but some variation between brands. Belgian made Brownings nearly always had 0.725" bores, most others were 0.730", except for Remington 1100 and 870 guns which were all over the place, mostly larger than 0.730". I actually found one 100 skeet barrel that measured 0.745" from the factory. I did a lot of screw-in chokes in single barrel guns, and the reamer and tap for the chokes came with 5 bushings from 0.730" down, and I had to buy blank bushings and turn them to size for the Remington barrels.

I just took delivery on a early 1960s Merkel 203 and noticed that the barrels are stamped .719".

Am I correct in assuming choke constrictions are relative to the individual gun's bore diameter? So if this Merkel is choked IC/Mod, the muzzles openings should be .709" and .699", while on a "standard" .729 12 gauge, those openings would be .719" and .709"?

I saw a Heiner Speeman with .708 bores.