I picked up a grenade Ultra Lite MPA chassis for a short action Remington 700. Want to make this into a fun hunting rifle that will be effective on elk on moderate distances (500-600 yards). I already own few hunting rifles that can do the job, just looking to tinker with an action that I have sitting around. So far I have come up with a 300 WSM or a 7mm SAUM for some options. Anyone here have any other suggestions or calibers that I should look into? Criteria needs it to be a short action caliber and be able to buy brass for it. Will be either doing a CarbonSix barrel or a Bartlein from NSS.