Greetings one and all! Stumbled upon your site recently while researching something else, when my eye caught. ".315 India". Hadn't seen this in about forty years, since an article about it was published in the late 1960s in "Guns Magazine".
It is simply the Indian version of the 8x50R Steyr, a.k.a. 8x50R Mannlicher, ; a.k.a. .315 Mannlicher Rimmed; the old Austrian military cartridge. When the .303 and .450 caliber cartridges were prohibited in India and the Sudan, BSA lost its market for Lee-Enfield sporters in those countries, and found a cartridge suitable for the Lee-Enfield action in the 8x50R, already being loaded in Britain. Ballistically it bettered the .303 slightly, 244 grain bullet at 2025 fps, versus 215 gr. @ 2060. So, when Ishapur phased out military Lee-Enfield production, it was only logical to follow in the foot steps of BSA for their sporting rifle. The French Lebel has a rim diameter considerable larger than the Lee-Enfield's bolt diameter, .630" vs. .585", and is NOT suitable for the lee-Enfield action.
The Type 45 Siamese cartridge is but a variant of the 8x50R Mannlicher. Same case length, but longer neck and thus shorter case body. It can be safely fired in a rifle chambered for the 8x50R Mannlicher.
Original military barrels had four rounded deep grooves, with a rifling twist of 250mm. I would assume that BSA/IOF used a ten inch (254mm) twist since they had the machinery for that one. Groove diameter is larger than that of the Mauser, at 8.25mm (as a sporter), with maximum bullet diamter the same at 8.22. If the bullets tend to break up, that's the fault of the IOF ammo. Bonded bullet technology is something new. Nobody but IOF loads it anymore, though the similar but longer 8x56R (misnamed Hungarian) is being produced in Serbia and available in the US.
Ishapur Lee-Enfields, while never comparing in quality to their British or Lithgow counterparts, were serviceable. From all I read on this forum, they must be of pretty sorry quality now.
As to aluminum bolts, or bolt handles, not likely. Not even from IOF! More likely a coating or plating. Industrial chrome plating is not the shiny "chrome" we are otherwise accustomed to.
So much on the .315. Time to quit beating up on Shahid. Namaste!