B.C. .546 is for 7mm 150 LRAB, ...270 cal 150 LRAB, BC = .591
your downrange comparison was based on .270cal 150 LRAB vs 7mm 168 LRAB.
OK. My bad – the velocity energy and drift numbers I used line up with 8000 feet altitude, not 7000 feet. I reran the numbers for 7000 feet and came up with this:
.270 Win, 150g LRAB @ .591 BC, 7000 ft altitude MPBR zero for 6” target:
.270 Win/150 LRAB @ 2910fps,
253 yds = zero point
299 yds = MPBR
47.1" = drop
2209fps - velocity
1626fpe = energy
16.2" = drift
17.7 ft-lbs recoil
Oops my mistake ,you said you could potentially spend $500 on a Mc Edge
I could take my M700 .30-06 and put a McMillan Edge on it for $500, with a final weight around 7.5 pounds, ...
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While I would love to have a .280AI or a 6.5-06AI or similar in a rifle that was 6 pounds all up,....
What I was talking about was options to spending $3500 to $4800 for a lighter weight rifle. Yeah, I’d rather buy a McMillan Edge for $500. But I haven’t done so for a variety of reasons, the most important being that doing so doesn’t have sufficient ROI.
How much does recoil really bother you considering you would relish a 6 lb 280 AI...?
Here’s what I said about recoil earlier in this thread. I don’t see any need to retype when I can just copy/paste:
“Who cares about recoil? I do. And my daughters do. We see no reason to put up with more recoil than necessary to reliably achieve the goal, which is why the big boomers rarely go to the range. I've hit clay pigeons on the 600-yard berm using my .338WM, .300WM, a .30-06, 6.5-06AI and .257 Roberts. And maybe my .243. The light kickers are definitely more fun to shoot and easier to shoot accurately. Especially so for my daughters.”
The key phrase in that is “We see no reason to put up with more recoil than necessary to reliably achieve the goal…”. If I had a rifle that was 6 pounds all up it would be a great carry rifle. I’d put up with the increased recoil for some purposes and choose a different rifle for others.
Not that I need a .280AI as I already have a 7mm RM and .280 Rem.
Would a 7-Mag or 30.06 at 7.5 lb, bother you anymore than a 6lb .280 A.I......?
Nope, because the recoil of the 7.5-pound rifles would be less for many loads.
Selecting middle of the road max.velocity and powder charge(Nosler data) for .280 AI 168 LRAB( ie; 58grains , 2850mv)
recoil for a 6lb rifle comes in at nearly 27 ft/lb.
7-Mag (at 7.5lbs) 168 LRAB (68 grains powder) at a more moderate 2900mv (than your orig. 3047 mv), gives 24.35 ft/lb recoil
and delivers better figures downrange than your .270win 150 LRAB.
First, I come up with a different recoil figure for a 168g bullet, 68g powder, 2900fps and 7.5lb rifle – 27.5 ft-lbs vs your 24.35 ft-lbs. Your number seems to line up better with a rifle/scope combo just under 8.5 pounds.
Comparing the .270/150g LRAB to the 7mm RM/168g LRAB load:
.270 Win, 150g LRAB @ .591 BC, 7000 ft altitude MPBR zero for 6” target, 600 yards, 2910fps MV:
253 yds = zero point
299 yds = MPBR
47.1" = drop
2209fps - velocity
1626fpe = energy
16.2" = drift
17.7 ft-lbs recoil (8.3lb rifle and scope = Ruger Hawkeye and Burris 3-9x40 FulField II))
7mm RM, 168g LRAB @ .616 B.C., 7000 ft altitude MPBR zero for 6” target, 600 yards, 2900fps MV:
253 yds = zero point
299 yds = MPBR
53.1" = drop
2227fps - velocity
1850fpe = energy
15.5" = drift
24.9 ft-lbs recoil (8.3lb rifle and scope)
27.5 ft-lbs recoil (7.5lb rifle and scope)
“… better figures downrange than your .270win 150 LRAB.”
???
Zero and MPBR ranges are identical. The .270 has a 6” advantage in drop while the 7mm RM has a 0.7” advantage in drift. Given the closeness in the drift, I’d say the advantage goes to the .270 Win. The 7mm RM has an insignificant 18fps advantage in retained velocity and a 224fpe advantage. Advantage 7mm RM, but given that the .270’s 2209fps and 1626fpe @ 600 is adequate for anything Daughter #1 is going to be doing in the foreseeable future, the extra 18fps and 224fpe are pretty much a “don’t care”.
Which brings us to recoil and the fact that the .270 is for Daughter #1. At 17.7 ft-lbs recoil it is 1.9 ft-lbs (11%) more than the .308 Win load she has been using. The 7mm RM 168g load is 41% more than the .270 load with similar weight (8.3lb) rifle/scope combos and 55% more than the .270 with a 7.5lb rifle/scope.
Based on the figures, the advantage easily goes to the .270 and 150g LRAB for Daughter #1’s purposes.
