30 cal has slightly less BC then 7mm, but usually more mass/meplat for terminal damage.
LA action, I would probably build a 28 Sherman Magnum. Take a 300 PRC, AI it, and then neck it to 7mm. Very similar to 7LRM from Gunwerks.
If you want 30cal, 300PRC with the Alex Wheeler reamer is solid but overkill.
I have a 30 Sherman Magnum (300PRC AI, but not necked to 7mm, as above.) Even more overkill.
7 SAUM and 300WSM are both good choices too, as you can run the very long high-BC monos. SA builds are more restrictive.
Take a 300WM and have it throated a bit longer. Then you can run factory 300WM ir handliad the longer monos to compete more with the 300 PRC.
Lots of options, but the question is .... will you end up with something too big to be too light to shoot well often?
That 30SM I have, all up, loaded withbrake and sling, is 11lb 7oz. It is a heavy hammer to hump around, and I am looking to lighten it a bit. Wish I would have just done an uber-light 280AI and been done with it.