300 RUM and 6.5 PRC. (Something different to try)

I have several 300 RUMS, 6.5 PRC's and 300 PRC's. Essentially all of them are shooting heavies. All short 21" barrels.
6.5 PRC with the 156 Berger.
300 RUM with 212 ELDX
300 PRC's with 230 and 215 Berger Hybrids. All absolute hammers, all loaded hot. Running Vit 570, 565 and 560. Velocities are up there. Especially with the short barrels.


So for my question.
I have a new short barreled 6.5 PRC (20") and a new long barreled 300 RUM at 26".

I just want to try something different here but not sure what. (Possibly solids. Hammer, Barnes, CX, cutting edge)
For once, just wanna run a lightweight bullet in both, but something that still flat kills. All prairie hunting. Deer to elk. I've just never ran any lightweight bullets and they've always kind of had me a little leery.

Any thoughts on what would be a good choice for something that's flat shooting? With a higher BC if possible

These are the two I plan on trying in my new Rum.

I'm running the Apex 116 grain in my 6.5 8 twist. Apex has 102, 116, and 123 grain in 6.5. They're about the sleekest monos out there. Maybe run the heaviest you can based on twist. They'll shoot very flat over 500 yards and carry enough velocity to work well beyond that. Fordy has more info than anyone I've seen based on culling game in Australia and he says they expand and kill well at 1800 fps.

@fordy had some tables of info posted here recently on the 6.5 monos. Look up his posts and you can find it.

You can run a 130 TTSX in the 300RUM 26", and depending on your throat and other, 3,700-3,800 fps is achievable. My 26" has a longer throat than my 28", and I can push the 130 TTSX just above 3,800 fps.
At my elevation, that load is zeroed @ 300 yards, is only a max height of 2.5" @ 250 yards, and is 6" low @ 400, 16" low @ 500 and 31" low @ 600 yards. It still has over 2,500 fps and 1,800 ft/lbs @ 600 yards.

Small and fast = 124H.H. in the 300RUM will get you 4000fps using H-4350.

85gr H.H in 6.5Prc still working on that??