Board Thread:Warhammer 40k General Discussion/@comment-211.26.90.25-20130827133032/@comment-3258762-20131016185252

" The Standard Bolt Round is standardised at .75 caliber"

It's right in the Bolter Ammunition page, no mention of .50 cal, I have no clue where you got this from. If you are simply saying that Bolters use the same ammo as Gyrojet guns did, I would frankly call that partial bullshit, this is 40k, there are new things in the Galaxy to use.