doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com German drilling, Miller & Val Greiss

I have a 16ga sxs / 7.7 mm rifle made by Miller & Val. I want to know what cartridge this takes and need help. The stamping on the rifle bbl indicates 7.7 mm, and in another place 2,5 g GDP (could be 2.5), but doesn't seem to indicate the length of cartridge, e.g. like 8/74. Looking into the chamber there doesn't appear to be much "necking down". Otherwise, I haven't done a mold or measured anything yet.

Is anyone familiar with what size of cartridge this gun might use and where I can find them if this is an "odd-ball" cartridge?

Thanks/G

Wellcome Gordie,
I would say 8x57IR (JR), made by RWS and Sellier & Bellot. But you must make a chamber cast and measure it to be sure.
Regards,
Jani

Could that mark be 2,5 GBP. This would be 2.5 grams (about 38grains) of "Gewehr Blättchenpulver" (Military Rifle Flake Powder). 7.7 would give a bore dia of .303" This may indicate a deep grooved bbl for a .318" 8mm bullet. Suggest a chamber cast & bore slugging to determine for sure. Certainly sounds within range for an 8x57JR, but not likely for an 8x57JRS.

Gordie - a small quantity of Cerro-safe low melt point metal can be ordered from Brownell's. I will make a very accurate chamber cast quickly, easily, and safely. Alternatively, sulfur can be used, but be careful with melting it. Clean and oil the barrel and chamber. Place a paper plug about an inch past the chamber and into the bore. Using gloves, long sleeves, and a face mask, melt a small quantity of sulfur in a small sauce pan (the yellow powder will turn to a sorta golden brownish liquid). Carefully pour into the chamber just to fill. Allow to cool. Use a solid rod of near bore diameter from the muzzle end to punch the cast out. Measure the cast and compare to chamber drawings of candidate cartridges ("Cartridges of the World" is an excellent reference. Should you discover that you have an uncommon chambering, consult "Cartridge Conversions" for tips on how to put the 'ole smoke pole back in service.

Speaking of chamber casting material, I will admitt that I use nothing but - candle wax. Strangely but so far I had no trouble identifying any of the odd chamberings/cartridges using this very simple method. - Jani

Jani - good point for identifying a chamber. I was thinking of die making where you have to match fairly exacting dimensions.

Gordie, slug the barrel for sure. If the chamber suggests a straight-walled cartridge, I would bet on 8X58.5R or 8X72R because, in my experience, Miller and Val Greiss favored these 8mm rounds. Ammo is harder to get than the 8X57R rounds, but they can be had and are fairly easy to reload. mike

Thanks everyone, good comments/information all. I'm off to melt something!

G

I have an 8x58.5R which is marked 2gr GBP / StMG. 2 grams (app 31 grains) flake powder with a steel jacketed bullet. I doubt seriously this round would have been proofed for 38 grains. The 8x72R may be a viable alternate, don't have knowledge as to their loading.

My caliber suggestion was based on the fact that in a Geco catalog from the 1930s the only 8mm (.318inch) rimmed cartridge using 2.5 grams of powder in one of its loadings is 8x57IR. -Jani