Truing 308 Gasser, bc vs. mv help

[brutus1776]

All:
Fairly new to the Kestrel world. Tested data on 6.5 bolt gun, out to 700, with garmin chrono and kestrel 5700 elite. Dead nuts all the way out.

I had previously been shooting off of Hornady 4dof with my 308 Gas gun.

Garmin chrono and a buddy’s old school chrono both but the MV at 2450 ish average. 16” ranier match barrel, 1-10 twist. Prints .5-.6 5 shot groups at 100y. GMM 168 gr to save a few bucks on practice vs 175. Gun is suppressed.

At 600 the data had me shooting about .4 mil high. At 300 solver called for 1.5 mil hold, but I was on water line at 1.2-1.3.

I trued the MV and it put speed at 2613 and shot the rest of the ammo I had. 300-600 was pretty dead on.

On the ride home the difference in actual chrono data vs trued seemed pretty different.

To true the BC to the 300y hold for example it would push the .218 g7 up to .5 ish. Which also sounds bad.

My range limitation is 700y.

Any advice? Stick with the high trued mv only? Will confirm back at range on Sunday. Thanks!!

 

[6.5SH]

Double check all the inputs for that gun profile, ~2450 fps out of a 16" is where it should be. If I had to venture a guess you are using a G7 number with G1 selected.

 

[brutus1776]

BC numbers checked out, I selected the bullet on the app. The app said it was .218, but said .221 (maybe .224 can’t remember off hand)on the box.

Got dope and trued velocity to 700 today on 8” steel. Numbers are now on average with in .2 all the way out now with my previous dope from 4dof. Trued muzzle velocity is somewhere around 2520 right now. Kestrel says I need to true around 785, will do first chance I get to a range that has an extra 100 yards.

I’m feeling more confident on this gun now with the 5700