The Firing Line Forums - View Single Post - Herstal- belgique rifle

T. O'Heir · July 27, 2014, 02:59 PM

You'll need more than the calibre, but that'll do for a start. Quick check is to use a vernier calipre to measure the inside diameter of the muzzle across the grooves of the rifling.
Better to slug the barrel though. Hammer a cast .30 calibre bullet or suitably sized lead fishing sinker though the barrel with a 1/4" brass rod and a plastic mallet, preferably from the chamber end, then measure with a micrometer or vernier. That will give you the calibre, but not the actual cartridge.
FN(Fabrique Nationale) Mausers, that we're all assuming and most likely is, came in multiple chamberings. Some, like the .308 and .30-06, use the same bullet diameter.

July 27, 2014, 02:59 PM	#9
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	You'll need more than the calibre, but that'll do for a start. Quick check is to use a vernier calipre to measure the inside diameter of the muzzle across the grooves of the rifling. Better to slug the barrel though. Hammer a cast .30 calibre bullet or suitably sized lead fishing sinker though the barrel with a 1/4" brass rod and a plastic mallet, preferably from the chamber end, then measure with a micrometer or vernier. That will give you the calibre, but not the actual cartridge. FN(Fabrique Nationale) Mausers, that we're all assuming and most likely is, came in multiple chamberings. Some, like the .308 and .30-06, use the same bullet diameter. __________________ Spelling and grammar count!