I have the 300 rum and it is a very accurate round. The 7mm should be just as good. It would be best suited for heavy bullets of great construction because of high velocity. It will kill anything you need to kill... period! The recoil is strong but with practice you will find it manageable. Ammo is expensive but if you reload it is not such an issue.
As good as the core locks are, in the magnums I would go at least a 150gr bonded bullet. Your asking a lot for a 140gr bullet to stand up to that velocity at the closer ranges. Matter of fact, I'd look for a 160gr load if it were me.
The corelokt ultra should be fine as it's a premium bullet but i to would suggest the Nosler Partition. I use 160gr Noslers inmy 7 Mag for just about everything. The 150gr Scriocco is also a good bullet for long range shooting. I would try a couple of different loads & see which one shoots the best in your rifle.
This tip is for anyone who does or does not use a rangefinder while bowhunting, here is a simple and easy way to judge the distance to your game. Whether you’re in a tree or on the ground you can use this method at any time. Marking the distance before a hunt from your stand is a helpful way to determine the distance. I use either colored pins and/or hunters tape to mark trees at 20, 30 and 40 yards in 3 different spots around my stand. With those 9 markers I have a good chance that...