At 600 yards:
.270 Win/150 LRAB @ 2910fps,
254 yds = zero point
300 yds = MPBR
52.6" = drop
2234fps - velocity
1662fpe = energy
15.5" = drift
17.7 ft-lbs recoil
7mm RM/168 LRAB @ 3047fps,
266 yds = zero point
314 yds = MPBR
45.6" = drop
2377fps - velocity
2108fpe = energy
13.7" = drift
27.9 ft-lbs recoil
your 150 LRAB (.591 BC ) and 168 LRAB (.616 BC) velocity-energy figures for 600yd, seem out of whack.
after running those bullets through a few different ballistic calculators, I consistently get more like
2037/1382 and 2180/1773 , respectively.
7-mag also offers option of 175 LRAB(.648 BC)
2800mv, delivers 2017/1581 @600yd.... 20.60 ft/lb recoil (8 lb rifle)
Starman -
I did muff the energy for the 168g LRAB. Not sure where I got 2108fpe but the correct number per my calculator is 1882fpe.
I'm using 7000 feet in altitude since we hunt elk from about 6200 to 10,000 feet.
So the corrected numbers should be thus:
.270 Win/150 LRAB @ 2910fps,
254 yds = zero point
300 yds = MPBR
52.6" = drop
2234fps - velocity
1662fpe = energy
15.5" = drift
17.7 ft-lbs recoil
7mm RM/168 LRAB @ 3047fps,
266 yds = zero point
314 yds = MPBR
45.6" = drop
2377fps - velocity
1882fpe = energy [corrected]
13.7" = drift
27.9 ft-lbs recoil
The 175 LRAB likely requires a much faster twist than my 9.5 7mm RM. A note form Hornady a couple days ago recommended 10 for their 150g ELD-X, 9.5 for the 162g and 8.5 for the 175g.
