What’s the official designation for this calibre? It measures about 7.8x52.
The official designation of a caliber should always be that which is given it by the company that introduces it, unless adopted by a military, or rights sold to another company, with a resulting change of designation. The designation for the cartridge in question is what is shown on the box - 7.82 Patriot. Any other name is just a description (for instance, adding the case length), not the official designation which in this case has been extablished by Lazzaroni and appears on the box.
Isn’t the Lazzeroni measured from the rifle barrel a little different than a typical rifle instead of land to land it is grove to groove?
The label says “7.82=.308”. Isn’t .308=7.62?
According to their website, the 7.82 uses .308" bullets. The ‘7.82’ may be construed as a marketing scheme of some sorts, although, if my math is correct, 7.82mm equals .307874". Calculating again, 7.62mm equals .300". The other .008" would account for a depth of rifling of .004".
Most, if not all, of Lazzeroni’s cartridges were designated by bullet size rather than the the traditional US method of bore size. It was strictly a marketing decision.
Ray, I think it’s more accurate to say that the bore size measurement is standard for military calibres (with the exception of 9mm), but commercial makers use bore, bullet or any other size which catches their fancy. Well-known US commercial cartridges which use bullet size include .308 Win, .264 Win, .244 Rem, .257 Roberts, .284 Win, .338 Win, .358 Win (in fact, Winchester generally seem to prefer bullet size).
Cartridges in the standard .22 centrefire calibre (.220 bore, .224 bullet) has been designated .219, .220, 221, .222, .223, .224 and .225 by different manufacturers!