eldeguello

Contrary to the implications of the word "mouser", the Mausers are not intended for shooting mice! IF you are shooting 7X57mm rounds in yours, and accuracy is as you describe, could it be that the 7mm (.284") bullets are too small around?? If so, but the 7X57mm ammo is easy to chamber, I suspect your rifle may be an 8X57mm (7.92X57JS) that uses .323" bullets instead of being a 7X57mm.

Ask a knowledgable friend, or the local gunsmith, to help you determine the correct ammunition!

harter66

I have heard that the early 7.92 x57 was in fact .318 bore . If this is an early "small ring" or 93 mauser or "clone" with a tight chamber the modern JS 8x57 that is .323 may not chamber as the neck would be at or beyond max.tolarance for a .318 bore .

Side by side with a 30 cal (of 308dia) the bore ought to be obviously larger or smaller .
If your mouser is a correct take from the gun you could have some odd 1 off wildcat or a "siamese" mauser with an
odd bore (7.5 or 7.7) which will not chamber 8x57 but would 7x57 .

It could also be that you have a bbl intended for very heavy or light bullets. I have a 1-12 308 that won't shoot 180's
and an 1-8.5 30-06 that won't shoot 130's . The 06' was a special order freak even in 1965 .

eldeguello

Actually, although there were some civilian rifles made in Germany in 8X57J (7,8X57mm) with .318" bores, the military rifles (GEW 1888's) made for that round were actually .322"-.323" in the groove diameter and when Germany adopted the 154-grain, .323"Spitzegeschoss (pointed bullet) in 1905,many M88's were converted to fire this load. The conversion consisted merely of reaming the chamber throats larger so the cartridge case could release the .323" bullets. Nothing else was done to them. (As a fact, IF the cartridge case neck expands enough to freely release the bullet, it is conceivably possible to shoot almost any size of bullet through a smaller bore. The most extreme example of this I have heard of -in the American Rifleman-was of a guy who rechambered a 6.5mm Arisaka to .30/'06, but left the bore at .264". He was shooting .30/'06 ammo thru this barrel. Bullets were being swaged down to .264" to get out the muzzle!)

In other words, the very first rifles made to shoot the 7,8X57J round had bores of .322"-.323" to start with, and fired .318" bullets! I assume the original, heavy, round-nose .318" bullets depended on swaging up on firing to obturate the larger groove-diameter bores.

That's strange, since the .308 Win. was introduced by Winchester in their Model 70 Featherweight with the 1/12" twist as standard. The one I owned would shoot every weight bulletfrom 110 up to 220 grains with quite good accuracy. I loaded mine with the Hornady 220-grain round nose & 48 grains of Norma N205powder for a MV of 2300 FPS. This load was quite accurate from the 1/12" twist 22" Winchester barrel.

Doe Dumper

elde I read that about the Arisaka as well. It was an article about them being the strongest action ever I think. Imagine what kind of pressure they were getting with that combo..lol.

Bernie P.

One thing you need to determine is whether it's the 7x57 or the 7x57R.They look almost identical but if I remember right the R stands for rimmed.That is to say the casing is rimmed near the bottom.