Certain marines hog the fuck out of it and nobody in Req pays attention. If you are first, you can casually ask for all heavy revolver bullets and every CT and RO will give them without blinking.
I'm not sure about the box of heavy speedloaders though, I have never seen req giving it out, or having at all in vendors. Even on wiki
(
https://cm-ss13.com/wiki/Requisition...niform_Vendors ) you have listed boxes of ammo they get and there is nothing about any
heavy revolver boxes.
And obviously nobody in their right mind orders heavy revolver bullets, its way weaker than slug effect (stuns for like a tic, or two), doesn't slow down at all and on top of that deals 37 dmg with 22 penetration so won't kill anything in a single speedloader and maybe will kill a runner if you hit every single shoot with that special snowflake revolver that deal more damage.
It would be better to take additional shotgun with slugs to combo it with any other gun, or pistol, than to take revolver and then combo it, because you have to swap those items and hands either way, holstering slug shotgun and taking out buckshot shotgun is as fast as holstering revolver and taking out buckshot shotgun.