20" 1/10 .308 to 1000 question

[Halfnutz]

Remington 700 .308 20 in 1/10 twist.

I am running 175gr MK w/44.4gr of Varget at 2618 FPS according to my Magnetospeed. Strelok show this drops to 1204 FPS at 900 yards.
Zero weather 54.2F 30.15 inHg.

I am looking at the TMK which if I can hold the same velocity, Strelok shows I can get to 1050 yds dropping to 1230 FPS.

Am I missing something in the calculations? It seems to good to be true that the slightly higher BC is going to make that much difference.

 

[The_Next_Generation]

Use density altitude and a g7 if possible, but that doesn’t sound too outlandish. What app are you using? I’d just go shoot it and see what happens..don’t get too wrapped around the axle.

 

[Halfnutz]

Use density altitude and a g7 if possible, but that doesn’t sound too outlandish. What app are you using? I’d just go shoot it and see what happens..don’t get too wrapped around the axle.

Strelok is what I have on my phone.

Thanks, I'll double chekthe settings and figure out how to get DA instead of Hg.

 

[Halfnutz]

G7 brings it down to 1219 FPS @ 975 yards.

Thanks again