Discussion in 'Firearms & Ammunition' started by DM Shooting, Feb 8, 2016.
Cheers guys dies are now on route so should be ordering powder and bullets soon.
Well dies arrived and 10 rounds of test ammo was made in a crappy stock and a crappy trigger only using express sight she shoot all 10 into a 3" group.
So a little tittivation and all should be good.
I know this is an old post and I'm also only guessing here, but it almost looks like 7.85 was the original land/bore dia and 8.1 the groove dia. Not sure what the 240 is. But the dia markings would make it the .318 bore
A .321 groove diameter is definitely intended for the smaller diameter 8mm bullet, as available from Woodleigh, etc. An Imperial rifle groove measurement of .323 is the absolute minimum for use of 8mm S bullets UNLESS the grooves are wider than the lands. You might get away with 8mm S diameter boat-tail bullets weighing less than 175 gr but that would be entirely at your own risk. Bear in mind that the 8x60, in both versions, made its name with heavy round-nose bullets, as per the aforementioned Woodleigh 200gr bullet.
The rule for cast lead is: .001 to .0015 larger than groove diameter.
The rule for cupronickel (or more commonly Luballoy equivalent) jacketed bullets is: .001 smaller then groove diameter UNLESS using boat-tail bullets, which, dependent upon shank length, tend to provide greater tolerance for tight barrels WITH SAFETY
OR, again, UNLESS the barrel grooves are wider then the lands.
For illustration, modern .308 Win and .30-06 rifles typically have a barrel groove diameter of .3085 inch. Every ‘.308’ bullet I have measured, i.e. Hornady, Sierra, Lapua, Speer; has had a diameter of .3075 inch.
240 probably refers to the standard 1-240mm twist rate, i.e. 1-9.45 inches.
Aha. I thought so but forgot to do the math...some old Mausers only list the bore diameter some do not list anything other than caliber....etc., etc....
Where is the pic of this rifle????
I think it was in the original post. Seems to be one now. Had barrel markings with the numbers mentioned above.
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