Range Report G7 BC's needed

[waveslayer]

I am having issues finding the G7 BC's for the 120gr. SMK's in 6.5 mm.

Why I'm at it anyone have the G7's for the: 175 SMK, 168 SMK and 77 gr SMK in .224?

 

[BobinNC]

Try here http://www.dtic.mil/dtic/tr/fulltext/u2/a554683.pdf
Page 9 of that document has most of the answers you seek.

 

[waveslayer]

I have that printed, still need the 120 SMK in 6.5mm

 

[vonbalkenbush]

Try here http://www.dtic.mil/dtic/tr/fulltext/u2/a554683.pdf
Page 9 of that document has most of the answers you seek.

Thanks for that link. Nice easy quick read with A LOT of very good information.

-VB

 

[BobinNC]

I have that printed, still need the 120 SMK in 6.5mm

Since the 6.5mm 107 gr SMK has nearly the identical G1 BC to the 6.5mm 120gr SMK I would use the 107gr G7 BC of 0.230, as a starting point. The 120gr SMK is a very poor performer BC wise, as the 123gr SMK is nearly 0.030 better in the G7 BC department and the 107gr is 13 grains lighter with identical down range ballistic performance, except you can shoot them faster. So, unless you a have a bunch of the 120's, the 123gr SMK or the 107gr seems a better bet at range.

 

[jbailey]

Since the 6.5mm 107 gr SMK has nearly the identical G1 BC to the 6.5mm 120gr SMK I would use the 107gr G7 BC of 0.230, as a starting point. The 120gr SMK is a very poor performer BC wise, as the 123gr SMK is nearly 0.030 better in the G7 BC department and the 107gr is 13 grains lighter with identical down range ballistic performance, except you can shoot them faster. So, unless you a have a bunch of the 120's, the 123gr SMK or the 107gr seems a better bet at range.

+1 on this.

Litz has a methology for converting G1's to G7's, which I could dig out if you really want a G7 on the 120 and you have a G1. Honestly however, G1 will do everything you need with a 120gr SMK, unless you are shooting it out a LONG WAYS (1500yds+) as the G1 and G7 curves don't start to differ until you get out that far.

 

[waveslayer]

+1 on this.

Litz has a methology for converting G1's to G7's, which I could dig out if you really want a G7 on the 120 and you have a G1. Honestly however, G1 will do everything you need with a 120gr SMK, unless you are shooting it out a LONG WAYS (1500yds+) as the G1 and G7 curves don't start to differ until you get out that far.

Good advice. I am trying to true my Shooter App to my actual data. Thanks so much

 

[LastShot300]

+1 on this.

Litz has a methology for converting G1's to G7's, which I could dig out if you really want a G7 on the 120 and you have a G1. Honestly however, G1 will do everything you need with a 120gr SMK, unless you are shooting it out a LONG WAYS (1500yds+) as the G1 and G7 curves don't start to differ until you get out that far.

+1