In 91 when H&K announced that they were going ot make hte MP5/ 94 in 10mm I wanted one for deer in the swamp. Though it would be great little carbine with lots of oomph for the deer in VA and NC.
Then the assault weapons ban came in and none were brought in.
It does not take a lot to kill a white tail.
If someone came up with a 35, 40, 41, 44, or 45 round that is rimless and necked, meets the state deer rifle round law and stuck it in a bolt action, I think you would have a winner of a round.
I say necked as the strait wall rinless rounds are hard to head space.
A rimmed round head spaces on the rim, a belted round head spaces on the belt, and a necked round like 30-06 head spaces on the shoulder.
Having a pistol round like 45ACP or 9mm head space on the mouth of the case is a pain for high pressure rounds like the above mentioned 44 Auto mag.