I've been struggling with this for a while now. I've been through 2 iPhone apps, loads of JBM print outs, stacks of chrono numbers with a cheap F1, and two scopes (swfa 5-20, and now a kahles 6-24) that have both passed tracking testes with flying colors... I'm shooting 140 A-max in a 25" 6.5cm with 42.4g of H4350. 1.8" scope height. I believe my velocity to be ~2800 fps, but I don't know what to think at this point... My 100yd zero is as good as its going to get...
7000 DA measured with a Kestrel, I go shoot 550yds and get impacts with perfect elevation with 2.8 mils. (JBM gives me a velocity of 2875fps for this)
7000 DA 700yds and I'm centered up at 4.4 mils (JBM tells me my velocity is 2800)
7000 DA 800yds and I'm getting hits with 5.4 mils (JBM tells me my velocity is 2800)
7000 DA 1150yds and I'm confirmed on steel with 10.2 mils (JBM puts me at a velocity of 2725 for this!)
I plug my info into JBM, using the Litz BC for my A-max's, and using a temp of 59 F, humidity 0, and a pressure of 24.25 to generate a 7000 DA dope card -Those numbers come straight from here:
Making Ballistic Cards Using Density Altitude
It says:
"To keep this simple, here are combinations of temperature and pressure that will give you DA steps from -4000 feet to 11,000 feet which you can put directly into your ballistic calculator. Leave the humidity set to zero. If you need other increments or steps outside this range, just use the online calculator.
DA.............Pressure......Temp(F.)
-4000.........29.765........0
-3000.........28.925........0
-2000.........28.106........0
-1000.........27.303........0
0................29.95.........59
1000...........29.055.......59
2000...........28.208.......59
3000...........27.382.......59
4000...........26.573.......59
5000...........25.783.......59
6000...........25.011.......59
7000...........24.257.......59
8000...........23.521.......59
9000...........22.802.......59
10000.........22.099.......59
11000.........21.414.......59
I'm desperate for a dope card that works. A JBM card with a velocity of 2875 had me tracking well to 600yds, then I lose it at 700 and beyond... A JBM card with a velocity of 2800 gets me on at 700-800 but has me missing close shots and long shots... Both 2875 and 2800fps have me missing all day long at 1000+ yds.... Pulling my hair out at this point. Got some big matches coming up and I need to get this sorted out!
Any help or suggestions would be GREATLY appreciated!
7000 DA measured with a Kestrel, I go shoot 550yds and get impacts with perfect elevation with 2.8 mils. (JBM gives me a velocity of 2875fps for this)
7000 DA 700yds and I'm centered up at 4.4 mils (JBM tells me my velocity is 2800)
7000 DA 800yds and I'm getting hits with 5.4 mils (JBM tells me my velocity is 2800)
7000 DA 1150yds and I'm confirmed on steel with 10.2 mils (JBM puts me at a velocity of 2725 for this!)
I plug my info into JBM, using the Litz BC for my A-max's, and using a temp of 59 F, humidity 0, and a pressure of 24.25 to generate a 7000 DA dope card -Those numbers come straight from here:
Making Ballistic Cards Using Density Altitude
It says:
"To keep this simple, here are combinations of temperature and pressure that will give you DA steps from -4000 feet to 11,000 feet which you can put directly into your ballistic calculator. Leave the humidity set to zero. If you need other increments or steps outside this range, just use the online calculator.
DA.............Pressure......Temp(F.)
-4000.........29.765........0
-3000.........28.925........0
-2000.........28.106........0
-1000.........27.303........0
0................29.95.........59
1000...........29.055.......59
2000...........28.208.......59
3000...........27.382.......59
4000...........26.573.......59
5000...........25.783.......59
6000...........25.011.......59
7000...........24.257.......59
8000...........23.521.......59
9000...........22.802.......59
10000.........22.099.......59
11000.........21.414.......59
I'm desperate for a dope card that works. A JBM card with a velocity of 2875 had me tracking well to 600yds, then I lose it at 700 and beyond... A JBM card with a velocity of 2800 gets me on at 700-800 but has me missing close shots and long shots... Both 2875 and 2800fps have me missing all day long at 1000+ yds.... Pulling my hair out at this point. Got some big matches coming up and I need to get this sorted out!
Any help or suggestions would be GREATLY appreciated!
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