Express proof

[JackL]

I have a 9.3x74R double barrel with the express proof mark (crowned E). I see the Standard Proofmarks refers to 5 express loads in the proof tables, but does not list those loads or explain the express proof further. Was it administered with or after or instead of initial proof? What were the loads for such proof? a particular percentage increase? Nitro powders? And what necessitated the submission to the express proof? Was it mandatory for certain calibers? Or submitted only upon request? Was it requested as a marketing ploy? I am curious to know anything that sheds light on it! Jack L

[mike ford]

My knowledge of German proofs is pretty limited, so I will defer to Axel if he answers. I believe Express proof was applied to those rifles,designated by the manufacturer(or whoever submitted it) to use Express ammunition. Heavier proof loads were used, to reflect the heavier duty loads.The table I have goes to 99.7 ga.(Axel provided a supplemental, including 8mm and 7mm) from 24 ga, in 5 steps,which I think are the "5 express loads" you refer to. This includes .577,.500, .450, .400, and .360, without regard to case length/shape. The table I have is for blackpowder, but express proof was used with cartridges intended for nitro powder( I have two 9.3x72R rifles so proofed). The first proof for a 99.7ga(.360)rifle was 9.75 grams of powder(New Rifle Flake Powder, mod 71) and a 11.2 gram ball, and a duty load of 3.25 grams of powder with a 8.4 gram ball ( this seems to be a round ball duty load, much different than the one your rifle was made for). I also am interested to see a more scholarly answer from someone.
Mike

[JackL]

Mike, Yours is a pretty scholarly answer from my point of view, and exactly what I was curious about! Thanks! Jack L.

[Axel E]

The use of the crown/E stamp indicating "Express" proof changed from 1911 (Zella-Mehlis) - !912 (Suhl). Before, together with the gauge numbers, it was used indicating proof for the blackpowder Express cartridges of British origin. The 1892 proof tables merely contain the then blackpowder proof- and service loads for the British BPE cartridges .360, .400, .450, .500 and .577. Apparently, the whole 1892 prooftables were simply translated into metric measurements from a British source. The gauge numbers and the corresponding millimeter dimensions are confusing, rather queer numbers. But if you convert the millimeters back into inches, you will find a system: the gauge numbers represent bore diameters in .01" increments, f.i. # 172.28 = 7.62 mm = .300", #156.14 = 7.87 mm = .310", # 141.95 = 8.13 mm = .320" and so on.
After 1912 he use changed: Usually guns were proofed for the pressure the current German factory loads produced. But a gunmaker could demand to have his gun proofed for a proprietary, custom or experimental load that generates pressure in excess of the factory standard. He then has to supply the gun to the proofhouse, together with a dozen or so of the intended service loads and/or components, loading tools and load data. The proofhouse will then concoct a load that gives about 30% more pressure than the intended service load and use this for the final proof instead of the standard proof load. Or the maker may specify to what maximum service pressure the gun has to be proofed. This practice is still followed today. In 1940 the crown/E stamp was replaced by an eagle/V stamp for "Verstärkter Beschuss" = enforced proof. Since 1952 it shows the German federal eagle instead of the Nazi one, but the rules remain the same.
A friend owns a double rifle drilling in 9.3x72R with the crown/E proofmark. It is regulated for a proprietary load by Chr.Funk. while the standard 9.3x72R load, 193gr at 2015 fps, was listed with 1550 atm pressure, the Funk load, 235gr at 2300 fps, had a pressure of 2100 atm. The drilling was proofed for this load, which exceeded the standard 9.3x72R proof load pressure. Another was an early, 1924, 7x64 Mauser action rifle by Stahl & Berger, Hamburg, proofed for Brenneke's proprietary high performance load which produced 3950 atm instead of the then standard 3600 atm.

[mike ford]

Axel,
The question wasn't mine, but I appreciate your answer a lot. This was a lot of good information.
Mike

[JackL]

Axel, Thank you! Great info! Question, Axel: Do you know, or do you have an opinion, whether the crown/E is an indication that the rifle (and I am speaking of double rifles) was regulated with a higher pressure load? ( and I am currently wondering about a rifle built in 1928 by Wilhelm Muchler Sohne, 9.3x74, marked for 18 gram steel jacketed bullet ) What do you think, Mike? Jack

[Axel E]

Now, as you are more specific, I can answer your question IMHO. As your 9.3x74R double rifle was made and proofed in Zella-Mehlis in 1928, I will try to explain the reason for the crown/E Express proofmark. The original standard load for the 9.3x74R was a 285 gr bullet in front of 54 gr R5 powder for a velocity of 2200 fps, pressure 2850 atm. In the late 1920s several enhanced loads were offered by the German ammo companies RWS and DWM, f.i. the RWS load with the same 18.5 g = 285 gr bullet in front of 59.4 gr "special powder" for 2420 fps, pressure 3100 fps, or the DWM load, 285 "Strong Jacket" bullet, 60 gr W1912 for 2457 fps, pressure 3300 atm. Regulation for one of these "Magnum" loads required the crown/E proof.
BTW, Wilhelm Müchler & Söhne was a country gunshop in Neuenrade, Westfalen, opened 1898 and existing until after WW2. Like many others he called his establishment a "factory" and for some time had a slightly more prestigious "mailbox address" in Zella-Mehlis too. He had most of "his" guns made by the Z-M guntrade. As all such country gunmakers they handled and sold anything a customer demanded, signing most of the better items with their own name as "maker". They advertized "hunting and target guns, pistols/revolvers, ammunition, handloading equipment, hunting gear, knifes, hardware".

[mike ford]

Jack,
You asked what I thought. Now that Axel has given the velocity of the loads your rifle was proofed for, you have a target velocity to work your handloads up to. This is assuming the gun shoots "wide" with normal loads. Just because the gun was proofed for the "magnum"loads, doesn't necessarily mean it was" regulated"with them. If the barrels shoot together with normal ammo, fine. If they shoot "wide" of each other, you should increase the velocity( with similar wt. bullets) until they shoot together. If you use lighter bullets, they may "cross". Sometimes it is hard to know if the barrels are shooting "wide" or "crossing". To determine this I shoot the right barrel on one target and the left barrel on another, and shoot the second barrel, just as quickly as I can get "on target". I also hold the rifle in both hands and rest my hand, rather than the rifle, on the bags.Make the rest high enough that you sit up straight. The common distance for regulation was 80-100 meters. Let us know how it goes.
Mike

[JackL]

Fantastic info, Axel! Thank you!

[JackL]

Thanks, Mike! Will do!

[JackL]

Axel and Mike, Tell me what you think--I was considering trying current factory loads, which advertise 285 grain bullets propelled at 2300 to 2360fps with 3359 to 3537foot pounds at muzzle. Even if it is just a guess, what do you think I could expect? Doesn't seem too far wide of the 2420/3300 that the express loads in the 1920s delivered. Jack

[Axel E]

Go ahead, of course you should try current, modern factory loads first, if availble. Your rifle should be safe to use any modern factory load that has to be within European CIP pressure limits. Since your rifle was made, factory and other loads achieve higher velocities with less pressure, as better, slower burning powders are availble now.

[JackL]

Thanks, Axel--will give it a try!