Thread: Ballistic truing conundrum

Yep, checking (again) the zero is next on the list. Should get that next weekend if weather plays ball.

SAUM 162 ELDM RL26 scope DOPE update
An update on previous posts, chasing down a difference of +1moa at 625 yards. Ballistic solvers predicted a 10moa come up, compared to my dialed come up of 9moa which gave a variance of 1-1.5in POI (low) vs POA. This set me re-checking some of the basics
1. Scope (VX6) dial up calibration. Turns out it’s dialing 1.083 in/moa, a 3% error. This equates very closely to 0.25moa at 625 yds
2. POI vs POA, checking measurements again and confirmed 1-1.5 in low at 625yd. This also equates to ~0.25 moa at 625yds. 



Correcting for 1&2 above my dial up should have been 9.25 moa and that equates to 9.5moa once you factor in the scope cal. This leaves an “error” of 0.5 moa to account for.


3. Re-check 200 yd zero, equates to 1.3in high at 100. Went to range this past weekend & put 5 shots down range. Average of 5 gave 1.5in high at 100. This equates to zero of 210 yards.

So correcting for all 3 above I still need to DOPE the muzzle velocity to get 9.5moa answer from solver. Adjusting speed to 3020fps (vs 2995fps measured) with a 210yd zero does the trick.

I also ran calcs using no adjustment for zero, just tweaking velocity (needs 3050 fps) to get 9.5 moa at 625yd. And another set just tweaking zero (needs 220 yd zero) leaving speed at 2995fps. However all 3 versions are less than 0.25 moa difference from 350 yards all the way out to 900, which is further than anything I’d attempt on game.
So I’ll proceed using 3020fps for muzzle velocity, 210 yd zero and adjusting the come up to account for scope dialing more than true moa.
Job done.

does your solver allow for scope correction?
for your 200yard zero why not just shoot at 200m and zero there?

Kestrel 5700 I think does have an option to input scope correction factor. But I’ve not played around with that feature as yet. Actually it’s pretty easy run the math in your head. 500 - 700 yards it’s reduce come up by 0.25 moa. Then 750 - 900 it’s reduce by 0.5 moa. Won’t be shooting any further than that & sub 500 it’s less than 1/4moa so you can’t dial it anyways.
Metres vs yards. Yeah, nah. My brain is wired in yards, feet, inches & moa.

Originally Posted by chainsaw

Kestrel 5700 I think does have an option to input scope correction factor. But I’ve not played around with that feature as yet. Actually it’s pretty easy run the math in your head. 500 - 700 yards it’s reduce come up by 0.25 moa. Then 750 - 900 it’s reduce by 0.5 moa. Won’t be shooting any further than that & sub 500 it’s less than 1/4moa so you can’t dial it anyways.
Metres vs yards. Yeah, nah. My brain is wired in yards, feet, inches & moa.

If you have nightforce you don't need that bit!

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not true. kahles had been tested as the most accurate dialing.

Originally Posted by blair993

not true. kahles had been tested as the most accurate dialing.

You can't bang six inch spikes in with a kahles.
To be fair nf has been the bench mark for modern optics and accurate dialing for years.
A lot of manufactures are now catching up that is a fact.
I support nf as they are a family owned southern hemisphere business that produces some of the toughest and most accurate optics in the world.

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Or take a 7.62x39 sideways thru the ocular and still keep functioning until the marine returned to base to get it replaced.

Sure they started out as Liteforce and still have an Adelaide address but I see NF as an American company now.
Oh, and I own their scopes as well, only humble NXSs though.

Recall the vid where a I guy shot a very respectable group with a NF scope . Fired a shot, removed scope from QD mounts, threw it as hard as he could down range, retrieved, re-attached, fired next shot, and so on.

Originally Posted by zimmer

Or take a 7.62x39 sideways thru the ocular and still keep functioning until the marine returned to base to get it replaced.

Sure they started out as Liteforce and still have an Adelaide address but I see NF as an American company now.
Oh, and I own their scopes as well, only humble NXSs though.

Recall the vid where a I guy shot a very respectable group with a NF scope . Fired a shot, removed scope from QD mounts, threw it as hard as he could down range, retrieved, re-attached, fired next shot, and so on.

Night force Australia has a subsidiary company USA.
The family that own and run it are very much aussie based with a couple of trips a year to Idaho.
They still do quit a bit of product development there in Aussie to as a very shooting oriented family.


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Even if it doesn't solve your problem go and shoot at 200yards! Don't trust the math of 1.3 high at 100.

Theres something about that distance. My DOPE from applied ballistics is always slightly out at 200m even when I've validated much further out.