My first rifle was a mouser 98 8mm. Dad rebarreled to 6mm cause varmints is what I mostly shot. Deer wasn’t commonly seen then.
I think that what you’re hunting might be a big consideration. Also, what ranges your son will be shooting. You say mostly deer and then possibly elk and antelope... I’ve hunted antelope with 7x57 and 270 both work fine. The 6.5 would too I suspect.
For elk I’d go with the 270 and 150 grain Partitions. But a 7mm with 150 PT’s would work too. The modified Savage case with a 6.5 bullet in it would probably work too - I think that’d be third choice though.
To me those options you mentioned here on the fire is similar to starting a discussion on what pickup is best while you and your co-workers just had a few at the bar.
I don’t care for short actions that much because of the inability of adjusting seating depth. But then the 300 Savage case length cartridges sort of bypass that issue.
I’m not one to fiddle with scope adjustments when out game hunting, maybe PD shooting though. That makes a difference to me. Shooting game at distance is not for me either. Actually, I look down upon that.
I have a couple 270’s and I do not find them wanting for any thing I’ve taken them out to do. I bought my wife a 7mm-08 and I have a 7x57 (similar). No issues with that cartridge either. The only 6.5 I’ve ever had was 50 years ago and bullets were slim pickings then.
Another part of the equation is money. Buying a stock for your Remington makes financial sense.
But whether you go with “A”, “B”, or “C”, I think you’ll by happy with your choice. Heck, if you go out west to shoot elk, you might want to buy a rifle just for that.
But I’ll have to add any cartridge that less than 100 or at least 75 years old is a “flash in the pan”.
I never thought I’d have AI cartridges and now I do. As soon as I run out of options, I still don’t have a 348, 358 Norma or a 38-55 or a.... maybe I’ll have a another flash in the pan like that 6mm Remington.
