New rifle what caliber should I choose?

[z987k]

But brass.....if it doesn't survive.......

You just buy a barrel worth of brass. Since peterson makes it, it's good brass. I'd imagine a box of 250 would cover it.
If I do a cartridge that isn't insanely well supported, I do that. Then it's never an issue.

 

[Huntnpack 2]

6.5-284 super easy to load for, accurate, low recoil, feeds like butter in LA,
Long brass life. Several powders work well.
Love’s the 140 Berger’s. Absolute Joy to shoot.

 

[HandgunHTR]

In my opinion, no matter what you go with, you are going to have more cartridge than you need, even if shooting monos. Heck, my 7-08 will keep the 130 class monos over 2000 fps at 400 yards.

But, since you have a long action, my recommendations are the following, in order of my preference

7X57AI
7X57
284 Win
6.5-06
6.5-284
6mm Rem AI
280 Rem (but have the barrel marked 7mm Express because that was too cool of a name to give up on)

 

[wind gypsy]

On a long action, in 7mm, 284win thoated long.

To really use that long action, the new 25 rpm has a lot to like above and beyond what a 25-06 can do.

This.

My only hesitation would be to research how to ensure those rebated rim cartridges feed well. I've never shot one of the 284 based cartridges but people seem to occasionally have trouble with feeding. Never had any issues with WSM/SAUM rebated cartridges feeding but they are typically in magazines designed for them.

On the brass front, its not like a 25 RPM is going to last for 4000 rounds. You could probably kill a barrel with 100 peices of brass if the brass isn't junk and you dont run it too hot.

Fast twist 25/06 would be cool and 270 would work too.

 

[dmm08300]

Always thought a 338-06 would be cool

 

[UnckleBob]

A 270 or 280AI will feed easily in the long action. Either will kill just about anything that needs killing. Neither will punish you with recoil.