That's cool. Because I have about 3/4 of a can of both

Like was said, don't discount IMR7828. I started with that and a 175 bullet and got good results. I then tried it with the 140BT's and it worked even better. I often get sub .5" groups at 100 yards and with my 26" barrel average 3350fps with that load. Here is a target I shot on a windy day, shot 3 I pulled, shots 4 & 5 were after a small scope adjustment.

Don't forget AA3100. Any of the listed powders will work great for you in 7mm rem mag. You might lean toward the 3100 or 4350 a bit since you are going to use 140 gr bullets. As to H and IMR being interchangeable-they are ONLY after you start a little low and work up. Different lots even make a difference. That's why I like the idea of buying 8 pound kegs.

I guess we all know that individual guns will tell you what they like the best, and the only wat you will find out is by trial and error, with a little good judgement and knowledge thrown in too.
My buddy's Sako 7 mag likes 4831 for the 140 gr., and my Ruger 77 likes 4350 with 139 gr. His rifle won't shoot my load well, and mine doesn't like his. Personally, I try to achieve the most accurate load I can with the most velocity. If the accuracy falls off with increased velocity, I try another combination or settle for what shoots best in that particular gun. I'm more of an accuracy nut than speed but achieving both in a safe, repeatable loading is why we handload, and the satisfaction we get from building our own custom-tailored ammo.

Well said pawildman.

I've tried a number of different powders loading for my 7 mm mag. I've settled on IMR 4350. I shoot out of a Savage 110 and the gun seems to like the loads with this powder. I'd strongly agree that experimentation is the key for all guns are as individual as their owners. Good luck and be safe with your reloading adventure trying to find that perfect load for your gun.

I have had success with all the powders mentioned with various 7mm rem mag. My current Rem Magshoots140-160gr bullets extremely well overtop of RL22, making it my current goto powder in this rifle.For comparison sakes with 140-150's -IMR 4350 and H4831, is used based on previous experience.