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How do I check the caliber on this Mauser?

usmc572usmc572 Member Posts: 25 ✭✭
edited September 2008 in Ask the Experts
I recently bought a Mauser Kar98k and it says 7.92mm on the receiver ring yet the rear potion on the bottom of the stock it says 7.62 it was 1 out of 2 rifles and one of which was an Israeli re-chamber into 7.62mm while the other was an 8mm I have no clue which it is and I would like to find out BEFORE I blow the gun up with the wrong cartridge.

Is there any way to check the caliber without putting in a bullet or reading the markings?

Help is much appreciated!


  • fordsixfordsix Member Posts: 8,722
    edited November -1
    well if it is chambered in 7.62x51 the 8mm which is longer will not even will have to cast the chamber with cherosafe..most israeli guns rechambered will have the new caliber stamped on the reciever ring in large stamp
  • Tailgunner1954Tailgunner1954 Member Posts: 7,815
    edited November -1
    Place a 30 cal bullet into the muzzle, if it's a 7.62x51, it shouldn't go all the way in. If it's 7.92x57 (8mm Mauser) it will easily swallow a 30cal bullet.
    Alt version of the above, use the ID blades of a caliper, the 7.62 will measure .308-.310 (depending on how accurate your caliper is and how sorn the muzzle is) and the 7.92 will measure .320-.325 across the grooves (widest part of the barrel).
    And finaly there is the correct way, which is to have a chamber cast made/measured.
  • He DogHe Dog Member Posts: 49,588 ✭✭✭✭
    edited November -1
    Do yourself a favor and do it right. Have a smith cast and measure the chamber.
  • B17-P51B17-P51 Member Posts: 2,185 ✭✭✭
    edited November -1
    Cerrosafe is extremely easy to use and cheap. Make a cast and be sure.
  • gotstolefromgotstolefrom Member Posts: 1,479 ✭✭✭✭✭
    edited November -1
    It is not that you have no clue what the caliber may be, is it ?
    Given that it is one or the other, Tailgunner's muzzle check using a bullet would be my EZ check. You have some ammo for each on hand, right ?

    A chamber cast IS more definitive, and would be THE method if you had no idea of the caliber, or if the caliber(s) had bore dimensions that were very close. The casting can provide additional usefull info, since you have no 'use history' of piece.

    ENJOY !!
  • jonkjonk Member Posts: 10,121
    edited November -1
    Near as I see it is either 7.62X51 Nato or 8mm German. I think the odds are it is the Nato round as the receiver marking was German from way back before the re-barrel.

    Easiest way is to try and chamber an 8mm round, and try aforementioned muzzle test.

    If you had NO idea, then I would measure the chamber with cerrosafe.
  • TRAP55TRAP55 Member Posts: 8,277 ✭✭✭
    edited November -1
    An easy rough guesstimate can be done by packing aluminum foil in the chamber, and carefully pushing it out with a cleaning rod. Then compare it to both calibers. If it's an Israeli Mauser, odds are high it's 8mm Mauser or 7.62 NATO.
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