Hi yall, wanting to know if there is anyone here that work with or have a bit of knowledge on tank guns. My main question is how do they get so much velocity out of them, specifically the rifled tank guns? For example, I have heard the M26 Pershing could fire an APC round at 4850 ft/s. Im not talking about APFSDS-light for caliber rounds either but ones that are full caliber and not so light. Is it the powders they use? Barrel length maybe?