Hello out here in cyber land .I have a question regarding a Mauser action stamped 8.7 mm what ammunition would be okay to use. i hear that a 308 bullet would be okay any input would be appreciated. thanks Jim
If the Barrel is stamped “8,7”…That is the German proofing (Bore) Calibre Marking for a Rifle Nominal Barrel in 9mm, such as a 9x47 (.35 Rem), Mauser 9x57 or 9x62, or even a 9x56 Mannlicher ( US equivalent is .35 calibre).
.308 is definitely NOT your cartridge.
Chamber casting will give you a more accurate idea of the actual chamber and cartridge.
AV Ballistics Technical Services
PS, this enquiry is better suited to www.gunboards.com, where Firearms and relevant ammo information (Mauser, Commercial/Sporter Boards) will be forthcoming.
Thank you for the information regards jim
I would also slug the bore. Just look it up on YouTube.com if not familiar how to do such.
You should consider that this is likely to be a 9.3mm bore diameter. Most older German (single and multi-barrel) guns that were chambered for 9.3x57R/70R/72R/80R weapons displayed the groove diameter as 8.7 (mm). The common 9.3x72R was generally shown as 8.7 / 72 and has often been misinterpreted as being a 9x72R. 9x72R ammo has even been created for these weapons with, I suspect, limited success.
Brad, what you mention it is true for those 9.3 mm rimmed cartridges because the guns that were chambered for them have a very deep rifling whose grooves usually measure 9.25-9.35 mm and its lands 8.75-8.85 mm. Typical proof markings in these barrels indicates “8,7 mm” or “8,8 mm” for either lead bullets (Bl. G. = Bleigeschoß) or copper jacketed bullets (K.m.G. = Kupfermantelgeschoß).
Barrel specifications from 1926 for a Mauser rifle indicates lands of 8.85 mm and grooves of 9.1 mm for the 9x57 Mauser, and lands of 9.05 mm and grooves of 9.3 mm for the 9.3x62 Mauser cartridge.