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Wow, I'm amazed at the variety of calculators available online. I just got in some Nosler Partitions in 7mm to work up a load for an elk hunt I have arranged in September. I could use my .308 I guess, but I can shoot farther with more authority with my big magnum and, well, I don't get to use it much here in the woods.:D I was a little worried about the plain base, but the bullet has a .475 BC, not bad at all. I have .257" and .308" bullets that don't top .400 in boat tail designs. The 150 Sierra Game King in 7 mm has a .535 BC, but it's a little frangible for elk. I've shot deer with it, it's explosive out to about 150 yards. I KNOW it wouldn't fully penetrate an elk's shoulder at close range.

So, anyway, I find I need a 2.5" above zero at 100 yards (likely) if I can get 3000 fps out of it which should be easy with RL22.

About 35 years ago, I started getting seriously into rifle ballistics. There was no such thing as online at the time and I couldn't afford an early PC, were high dollar. Safeway was selling out these Timex Sinclair toy computers which is what I bought at first and it worked well. Then I bought a Tandy Color 3 and thought I was up town. :rofl: You couldn't buy anything for exterior ballistics, so I set about writing my own software in BASIC. I knew it would entail calculus as it was a "rate of change" calculation. I wasn't the sharpest tack in my calculus class, but I made it through. My wife says "D is for Deploma" :rofl: But, Sierra Bullets was running an ad in the 'zines at the time, call an 800 number and "ask the bulletsmith". So, I called 'em, told 'em what I wanted to do, and this very helpful fellow sent me copies of an article from "Rifle" magazine with all the calculations I needed derived into "simple" (okay, sorta long winded) algebraic equations for drop, wind drift, target lead, etc. All I was really interested in was drop and calculating a point blank range sight in.

My program (after several days of debugging) worked fantastic. I even added calculations I knew (I wasn't as dumb in statistics) for calculating mean velocity, energy, and standard deviation. When I finally got a PC in 1996 and we got online, I found ONE free ballistics calculator, a free download. I don't seem to have that anymore, though I probably burned it on a disc I have here somewhere. I googled "ballistics calculator" and, MAN, they're all over the place, just enter your bullet, if the site doesn't have a bullet library enter your BC. Enter your velocity and the machine does the rest. :D I doubt Sierra and others even offer software for sale. What would be the point anymore? :rofl:

Anyway, looks like my 7 mag will do a fine job with the partition. Here's what I came up with. I think using RL22, I can attain 3000 fps I get 3200 from a 150 Game King. :D Bear in mine, I won't shoot beyond 400 yards and THAT had better be in windless, flat terrain conditions. Too many variables and if I shoot, I have to be comfortable with the shot.
7mm magnum 160 Nosler Partition ballistics proposed




Range  Drop  Drop Windage Windage Velocity Mach Energy Time Lead Lead
(yd) (in) (MOA) (in) (MOA) (ft/s) (none) (ft•lbs) (s) (in) (MOA)
0 -1.5 *** 0.0 *** 3013.9 2.700 3226.6 0.000 0.0 ***
50 1.0 1.9 0.0 0.0 2910.7 2.607 3009.3 0.051 0.0 0.0
100 2.5 2.4 0.0 0.0 2809.9 2.517 2804.5 0.103 0.0 0.0
150 2.9 1.8 0.0 0.0 2711.3 2.429 2611.3 0.157 0.0 0.0
200 2.1 1.0 0.0 0.0 2615.0 2.342 2429.0 0.214 0.0 0.0
250 -0.0 -0.0 0.0 0.0 2520.7 2.258 2256.9 0.272 0.0 0.0
300 -3.4 -1.1 0.0 0.0 2428.3 2.175 2094.6 0.333 0.0 0.0
350 -8.4 -2.3 0.0 0.0 2337.9 2.094 1941.5 0.396 0.0 0.0
400 -14.9 -3.5 0.0 0.0 2249.4 2.015 1797.3 0.461 0.0 0.0
450 -23.1 -4.9 0.0 0.0 2162.7 1.937 1661.4 0.529 0.0 0.0
500 -33.2 -6.3 0.0 0.0 2077.9 1.861 1533.7 0.600 0.0 0.0


Sorry about the alignment. Can't seem to clean that up. Oh, well.
 
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I usually go to Berger's site or Hornady's since I'm a member of Team Hornady. But the JBM you linked to is as good as any.;)
 
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