Raimey,
First of all, you will not be able to buy 6.5x70R ammo loaded by any commercial manufacturer in either Suhl or Austria; you will either have to load it yourself or have a custom handloader load it for you. Whoever loads the ammo will have to match it to the rifle (within accepted tolerances). The nominal caliber is only the "name" of the cartridge the gun is chambered to use. Some "names" are established to fit actual dimensions, some are established to fit nominal dimensions (6.5mm is .256", but a nominal 6.5 mm bullet is .264-5" or 6.7mm diameter). Some cartridges have different names to avoid confusion but use the same size bullet (.218 Bee, .219 Wasp, .220 Swift, .221 Fireball, .222 Remington, .223 Remington, and .225 Winchester all use .224"diameter bullets), some have the same nominal size but different actual size (38 S&W Special is .357", 38S&W is .361", 38Colt is .375"), sometimes the same cartridge has different names for advertising (38S&W and 38Colt New Police are the same). Some people think the metric system avoids confusion, but subject of this thread shows that is not entirely true. As long as commercial ammo is available, using ammo that matches the nominal caliber of the gun is correct. However, once you have to load your own ammo, you have to make sure the components match the gun. Custom handloaders should also match components to the gun. Failure to do this results in ammo that may not chamber or may not perform well or may be dangerous. Whoever loaded the ammo that came with your rifle, correctly matched the bullet to the actual groove diameter of the rifle rather than matching the nominal diameter. The difference is the manufacturer of the gun used a barrel that matched the diameter of a nominal 6.5mm bullet rather than the actual dimensions of the cartridge established by the designer. Since you can't buy ammo for your gun at the local "Mal-Mart", as long as you understand the difference and use the correct components, your rifle will perform as intended.
To measure the slug, measure across the lands of the slug to determine the groove diameter of the barrel. This is fine as long as the barrel has an even number of grooves and the mic. or caliper measures land to land on the slug. If the barrel has an uneven number of grooves the mic. will measure from land to groove and give an incorrect measurement unless you use a special micrometer made to measure such slugs. A correct measurement can be approximated by a couple different methods, one of which is to rotate the slug between the jaws of a dial or digital caliper as you mentioned. You don't have to rotate it a full round, if you are careful rotating over one land to the next is enough. Since a mic. operates by a threaded rod, it won't work for this method.
Mike
Carcano is correct that using a soft round ball, larger than the barrel, is much easier. I didn't comment because it was already done.
Last edited by Der Ami; 08/28/25 11:39 AM.
