Of course I would have to choose my
Remington M40 700 Long Range Rifle
300 Remington Ultra Magnum with this Load
225gr. - ELD-MATCH - Bullet
103gr. - MAGNUM - Powder
9 1/2 M - Remington - Primer
3,100fps. - Velocity
0.730 - Ballistic Coefficient
3.645" - Cartridge Overall Length
Out of what I personally have in 30 cal I'd take my 300 win. If I was building a gun for shooting a mile in 30 cal it would be the 300 Norma. Although far from optimal I have personally and been witness to numerous guys connecting at a mile with a 308. Decent gun, a good ballistic app, a guy that's really good at reading and calling the wind and a few shots. So it just depends what your trying to do.
30-06. Why its my all time favorite 30 cal. It takes with my load 64 MOA to get a mile. with only 1147 fps @ a mile. BUT IF I wanted to get real serious. I would ran a big 30 Like my BSM that can get a 230smk to around 3400fps. Its very consistent and with the BC of the Bullet and speed. Its still going about 1620FPS @ one mile. And only takes 39.25 MOA of elevation for that shot with a 100 yard zero.
Now if I could or would get a fancy lathe turned high BC target bullet it would be a lot faster at a mile....
I have a Savage model 111 in 300 win mag. that I bought from a long range shooter a few years ago. He used to use it as his go to 1 mile shooter. He claimed to be able to put rounds on a 16" steel plate consistently at 1 mile. I do not plan to shoot anywhere near that as I purchased the rifle for elk hunting. I will say I got real lucky after putting an Eliminator 3 scope on it and bore sighting it I was able to do a 2 shot zero using a lead sled at 100 yards. That was shooting factory Winchester 180gr. Ballistic Silvertip ammo.