doublegunshop.com - home Forums General Discussion German & Austrian Sporting Guns @ doublegunshop.com German shotgun 1920s proof tolerances

I love German shotguns pre-War. I have several and wish to go hunting with them. They are chambered in 2 1/2 to 2 5/8. I was able to buy factory loaded, Gamebore 2 1/2 12, 20, and 16 gauge shells out of England. They advertised its safe to shoot in old doubles. I think it runs 8600 psi. I am wondering if that’s pushing the upper limits of these old guns. I have 1 oz 20 and 16 gauge loads from them and 1 1/8 12 gauge . What does everyone think?

Um, if it were me, I would judge each gun individually or as a group in a gun era. I am not too sure about 20 bore, but hopefully Hause will stop by & inform us. But I am a huge fan of Gamebore, specifically the shot if loaded with the Diamond Shot, but Gamebore is notoriously Hot. I live on the edge & I would cap pressure for most barrels @ 7500 psi. Now you might be referring to Regal? Armusa is always a Great option and then always consider RST, when, where available. The platform lockup, tube steel, etc. are all factors.

Serbus,

Raimey
rse

KurtO,
Enjoy the guns, get some birds for Christmas. If you got the 8600psi figure advertisements, it is likely the "maximum".
Mike

Shooters in Great Britain and the Continent had a number of powders from which to choose; of course the Germans were fond of "Schultze", Dynamit Nobel’s Troisdorf Powder Co. (“Troisdorf” Bulk Smokeless and “New Troisdoft”, a Dense Smokeless) and Wolffe & Co.'s Walsrode Smokeless & Waterproof Gun Powder Co.

Comparative powder charges from 1896



and published pressures; measured by lead crushers so for modern transducer numbers add 10 - 14%

I've not found published German proof house proof and service pressures but they were very likely the same as those of the Belgian proof house. After the proof house revisions of 1924, the Certificat d’epreuve specified:
“The pressure developed, measured by crusher type device, lower or equal to 600 kg per square centimeter for sizes 16, l2, 10, 8 & 4; 670 kg per square cm for sizes 20, 24 and smaller.”
600 kg/cm2 = 8534 psi maximum SERVICE pressure;
670 kg/cm2 = 9530 psi maximum SERVICE pressure
+ 10 - 14% by piezoelectric transducer measurement
20 g was PROVED at 1000 kg/cm2 = 14,223 psi
12g PROVED at 900 kg/cm2 = 12,801 psi
Modern transducer numbers for 20g would be close to 15,500 psi; 12g about 14,000 psi

Sauer (I don't know the DOM) kindly provided the recommended service load for this 16g
2 gram "Schultze" (probably "New Schultze" 12 grains/dram) = 31 grains = 2.58 Dr.Eq.
27 grams lead = .95 oz.
Essentially today's 16g Game Load 1 oz. at 1165 fps

Thanks Hause. From what I see on the Sauer, the Voluntary Semi-Smokeless Proof bounds the date for the most part from the late 1890s till 1912. With this one being on the flats and not on the sides of the tubes, I would say much closer to 1912 than 1900.

Serbus,

Raimey
rse

Always wanted clarification on this. Is it service pressure or proof? I also thought service pressure.

Voluntary Semi - Smokeless Proof for Service Load, typically. I think, I think there are some scattered cases where the Proof Load was applied & it led to dire consequences. I will try to dig on this..... This Voluntary Proof Effort warranted an additional fee.

Serbus,

Raimey
rse

And considering the example is a pre-WW1 Sauer, then it will wear Krupp Tubes and the 16 bore GameBore Regals - Diamond Shot with F2 powder is clocked @ 1200 ft/s, that is about the max I would ignite in those tubes...... Just um an effort to keep everything on face....

Serbus,

Raimey
rse