Hunting & Fishing .308 drop chart with G7 BC

[BigMikey]

hey guys, I'm testing 155 Berger VLD hunting bullets for my 308. I shot several rounds at 600 and 1000yds, and was within 6-10 inches of elevation using the traditional G1 BC. I was looking to fine tune my chart. The guys at Berger recommend using the G7 BC for long range applications. I plugged that into my exbal program and it is drastically different, from 1/2moa at 200yds, all the way to 38moa at 1K (difference). Has anyone ran into this? what are your guys' experiences with this G7 BC?

thanks guys,

Mike

 

[ChadTRG42]

Re: .308 drop chart with G7 BC

When I stopped using the G1 and went to the G7, I was on target much more with first round hits with the G7 BC. I make a custom drop chart each time I go to a place/match to go shoot. I enter the estimated temp(s), known elevation, bullet fps, correct scope height above bore, estimated pressure, and humidity.
If you enter the correct information, it should spit out a trajectory chart spot on. I use this web site for my drop data. It's the same a JBM. If you are off at 200 yards, I'd check your scope height. Mine is at 2.25 (which is high), as most drop chart programs assume a 1.5" height. This is enough to cause it to be off at 200 by the 1/2 MOA. Hope this hepls.

Chad

 

[Lindy]

Re: .308 drop chart with G7 BC

Exbal does not do G7 BCs. Gerald's GModels program does, but it doesn't run on a PDA:

http://www.perry-systems.com/Gmodels.pdf

If you want to use G7 BCs, the easiest way is to use JBM Ballistics, and choose a bullet with an annotation in the bullet library of "Litz".

http://www.jbmballistics.com/cgi-bin/jbmtraj-5.0.cgi

If you want corrected G1 BCs to use in program like Exbal, buy this book, which you should own anyway:

http://www.appliedballisticsllc.com/index_files/Book.htm

 

[BigMikey]

Re: .308 drop chart with G7 BC

thanks guys for all your help! this will give me something to go off of.

 

[19818119]

Re: .308 drop chart with G7 BC

Another option if you have an iPhone is to use Ballistic FTE which has the option of inputing G7 BC's.

Rath