Цитата Сообщение от Hammer
Источника где бы прямо говорилось что для УБ использовались патроны 12,7x108 у меня сейчас нету.
На тот момент в СССР выпускались только 12,7x108(ДШК)и 12,7x108R(ШВАК)
Второй был специально предназначен для ШВАК. Конструкция узла подачи УБ принципиально позволяла применить тот и другой.
Слова чела, который считается как бы экспертом.

That sounds extremely unlikely. The key problem would be the extractor claw, which hooks around the rim of the cartridge as it is chambered and pulls the fired case clear. These have to be sized to fit the rim. Now if you have two cartridges which are the same size and shape except that one is rimmed and the other rimless (it has a rim of course, it is just the same diameter as the case body and separated from it by an extractor groove), then the rimmmed cartridge has, by definition, a rim of significantly greater diameter and therefore would need a different extractor to fit.

I have never heard of any weapon, of any type, able to fire rimmed and rimless versions of the same cartridge except for certain revolvers chambered for the .45 Auto Rim (the same as the .45 ACP but rimmed) which could fire the ACP - but only with special clips fitted to the cases to hold them in place.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk