doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Two inch Twelve gauge

Drew, at one time 2” guns had to pass the same proof as 2 1/2” guns. I think that is why that gun has a 1 1/8 ounce proof stamp. I sure would nit have shot any 1 1-8 loads in the 2” I had. Some of the factory loads would rattle your fillings. I can only imagine what a 1 1/8 ounce would be like.

Yes, the Proof House declared in 35' that 2" would be proved at the max. service pressure of 2 1/2" (and 2 5/8") guns = 3 Dr. Eq. with 1 1/8 oz. shot = 3 1/4 tons by LUP or about 9,800 psi by Burrard's conversion

I went through the thread trying to document the proof level by dates:
33' - 7/8 oz.
35' - One 7/8 oz. and two 1 oz.
36', 37', 38' - one each and all 7/8 oz.
38' - 1 1/8 oz.
46' - 7/8 oz.
50' - 1 1/8 oz.
54' - 1 1/8 oz.
56' - 1 1/8 oz.
and the undated Alex Martin S&W 1 1/8 oz.
It appears that the proof pressures were the same, but the service LOAD was marked differently.

1947 edition of Burrard's The Modern Shotgun lists a "Low Velocity: 2" load with 2.2 Dr. Eq. (24 grains of a 33 grain powder) and 1 oz. shot. No pressure was provided.
It is possible those 2" guns marked 1 oz. and 1 1/8 oz. were to use the lighter powder load?

This however from Henry Sharp, Shooting Times, 1939 back on p. 8 listing 2 loads for the 2", with the 1 oz. just introduced:
26 grains Curtis’s & Harvey “Diamond Smokeless” with 7/8 oz. shot = 2.36 Dr. Eq
28 grains "Empire" with 1 oz. shot = 2.55 Dr. Eq.

The "highest mean service pressure" for the 2 1/2” cartridge was lowered in 1954 to 3 tons - 8,960 psi and for the 2” cartridge to 2 3/4 tons = about 8,200 psi.
Standard service is about 75% of max. service

The 1955 edition of Burrard's lists standard load & pressures for 2" cartridges at 7/8 oz. 2.36 Dr. Eq. (26 grains of 33 grain = 3 Dr.Eq. powder) Service 2.25 tons = 6,440 psi; Max. Service 3.0 tons = 8,960 psi.

Josh has listed a high condition 2" John Dickson & Son
https://www.gunsinternational.com/g...ase-ammo-available-.cfm?gun_id=102365947



The date code 'T' is 1938-1939 and proved for 1 1/8 oz. which is the earliest we've seen at that oz.




A 1946 Joseph Lang 2" proved for 7/8 oz.
https://www.gunsinternational.com/g...on-2-quot-12-gauge-.cfm?gun_id=102352516

Webley & Scott 2". No mention of proof nor DOM
https://www.gunsinternational.com/g...ott-2-quot-12-gauge.cfm?gun_id=102319099

The above is a re-badged Skimin & Wood. One giveaway is the J.A. initials on the left barrel. While Dickson did make a handful of 2" guns, lock, stock and barrels, this isn't one of them. A lovely gun, nonetheless. Gil

Drew,
What are the differences in Standard Service and Max. Service as it applies to usage? How does that reflect what the average owner should load and use the gun?

SAAMI says it another way Brent:
"Maximum average pressure for 2 3/4" and 3” shotgun shells will be 11,500 PSI +/- 900 psi, with some maximum extreme variability not to exceed an uber-max of 12,500 psi +/-900 psi"

So a SAAMI standard shell may actually run 13,400 psi and that would be the "Maximum Individual Service Working Limit" or per CIP "Maximal Statistical Individual Pressure"

And the pressure we should aim for is the "Standard Service" pressure.

Vic Venters, Shooting Sportsman, March-April 2012, “CIP Proof”
“Although the Maximum Mean Pressures for service loads for standard proof (850 BAR) guns are 740 BAR (10,733 psi), CIP regulated cartridge manufacturers typically work to lower pressures...between 450 BAR (6,527 psi) and 650 BAR (9,427 psi) as measured by CIP piezo transducers.”

Pressures published by Burrard in 1955

Thanks Drew. I was thinking of Max Service as the upper bound of a 95 or 99% confidence interval, which is more or less about right.

Back on p.3 Ted proved himself the sage of DoubleGun
"A 2” 12 gauge would make a lot of sense-if the 20 gauge hadn’t been invented."

Reviewing Burrard's 1947 2nd Edition of The Modern Shotgun and there is very little regarding the 2" 12g, but found this:
"The 2-inch 12-bore...was originally introduced as an alternative to the 20-bore (when desiring a lighter gun) and fired the standard 2 1/2-inch 20-bore charge of 3/4 ounce, its purpose being to eliminate the danger caused by the accidental intermingling of 12- and 20-bore cartridges...But experience proved that this shot charge was too light (related to lower pressures and velocity) so the shot charge was increased to the standard 2 1/2-inch 16-bore weight of 7/8 ounce."

The point of Lancaster's pre-1900 "Pygmies" 1 oz. load was to enable the sportsman to carry more shells, not a lighter gun.

The cheap, but, effective, Federal 20 gauge promo loads are showing up, in quantity, at the local Wally World-I use them to good effect trying to perfect my shooting off the right hand shoulder with my (GASP!!!) 1100 gas gun. My hope is to be somewhat proficient with one of the 20 gauge doubles about the place come fall. I tried my Brother’s 12 gauge 1100, and, damn if I don’t shoot better, and enjoy, the 20 gauge version, more.

Little is promised to us. Much less this bit of hope of mine, but, hope is all I’ve got.

Two inch 12 gauge ammunition has not been noted to be in stock. I would not consider that a criticism of Wally.

My late Father, 22 years active duty, 8 years of making reservist’s lives hell for one weekend a month, considered hunting trips to be gauge specific, to all participants. Logistics are a big deal to Marines, I’ve noticed.

Best,
Ted

20s are fine, if that's what you like, but hunting is more to me than killing a bird. The 2" 12 has added immensely to my hunting season, and we are yet 2 months out from opening day. What Wally stocks or doesn't stock means nothing to me.