Dead on at 400, gun shoots left at 100?

[shortpants]

Wow! That just seems like a huge amount of spin drift.

Seems way high to me. I get 6" of SD at 1000 yds.

 

[Bravo 4]

Seems way high to me. I get 6" of SD at 1000 yds.

I've been using .2 mils with my .338 Edge and 300 SMK which is less then 3/4 moa, so it's close to what you have been getting. With .308 and 175 SMk I've been using .3 mils and seem to be doing ok.

 

[backwoods83]

Its most likely more in the can't of the cross hairs but in a Savage the stability factor for a 250smk at 3050fps at 1000' is roughly 2.85 or just under .4mils or about 11" of drift at 1k, the 300smk at 2800fps at 1000' has a stability factor around 1.9 or just under .3mils or about 9.5" of drift. But all this is minor corrections and should be settled at 100yrds dead on, and then adjusted for there after.

 

[WEATHERBY460]

i am doing the paper test....i might be off from 0moa to 20moa (80 clicks) about 1/4" inch on paper, tapering to the left of the line.

so looking at my ballistic chart at 550 yards i am at 40 clicks or 10moa

if 20 moa is off by .25" then 10 moa is off by .125"

.125"x5.5 (550 yards)=.625"
.125"x4 (400 yards)=.5"

so i should have only been off about 1/2" at 400 yards? is my math right?

 

[backwoods83]

Your math is right, your thinking is wrong, moa would be 2, you would be two inches off at 400 but spin drift is bringing you back because your crosshair is canted in the right direction.