Re: .30 cal 155 grainers
Vin,
To get the 155s to 1k, I hear you have to drive them pretty hard. Depending on where you shoot, 2,850+ seems to be about where you need to be to get them there. Going by JBM ballistics, a lower velocity may get that far, but to do so consistently and accurately you need as much speed as you can get.
I don't think you will have much problem with either one of your rigs. I'm working up both 155s and 175s with a 20" AR; my last range trip saw my 155 grain Nosler CCs with IMR8208 pushing close to 3,000 fps if not more judging by my drop. I was getting ejector wipe on every case, so I decided to pull the bullets from the rest of those loads and go to the lower node. Also from my last range trip, I did a ladder test with 175 grain Nosler CCs and Reloder-17, settling on 48.8 grains in a Winchester case. At 570 yards I had 12 1/2 MOA of elevation, telling me that they were a smidgen over 2,700 fps with no pressure signs whatsoever.
I would recommend starting with a lower charge and working up though. In the past I got 2,600 fps from Varget under the same 175 grain bullets. I think the heavies are the way to go, personally.