I just received my Summer 2013 copy of the AFTE Journal and was amazed by an article by Muhammad Ilyas Yasin from the Punjab Forensic Science Agency. It appears that many AK rifles in both countries are being modified so that they can fire both 7.62x39mm and 7.92x33mm ammunition. In fact, in Pakistan, rifles are being manufactured with this dual caliber capability. The modification is described as:
The new/modified rifle is locally known as a “44 Bore Rifle” or a “KK Rifle”. The 44 is apparently derived from the StG44 from the original German weapon or from L44A1 which is found on the headstamp of most of the reloaded cartridges. The article illustrates 7.62x51 cases headstamps POF 84 L2A2 and (+) MEN95L0003 and 7,92x57 cases with the old 1947 Turkish headstamp which have been modified to 7.92x33mm.
Apparently 7.62x51mm cases are readily available but have a head diameter that is slightly too large to be reloaded into 7.62x39 so the dual caliber chamber was developed. Fired 7.62x39mm cases wind up with a double shoulder, or actually a triple shoulder depending on how close you look.
The author makes an interesting comment. The local gunsmiths and loaders believe that they invented the 7.62x33mm cartridge and do not know of it’s use in WWII.
Something new for you 7.92x33mm collectors out there!