Mate, id just get a decent scope and load sorted for the 270 if not already and use the rest for ammo. i comfortably push my 270 to 800 yards on deer using 150 Berger's but the ranges you mention you can easily do that even with a 130gr sst, the 150sst not far behind the Berger's BC. i run a hot load though, 150gr going 2900fps but even with a mild load the 270 can do the range you are after.
if you chuck a 3-16x scope onto the 270 its sorted for an all-round for bush and long range.
If you just want a new rifle, my pick in 30 cal is 300wsm or even PRC and 7mm is 7PRC, BTW if you dont reload most factory 7 rem mag ammo doesn't give much over the 270 anyway.
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