drop chart and chronograph drop chart

[WildRose]

gun)

+1 for Mike33
If you have 5 different Chronographs you're going to have 5 different readings even if you shoot through all 5 with the same bullet.
I went through the time and wasted money to figure this out. What matters is where the bullet actually hits. I wouldn't even mess around with the MV and just do like someone suggested and shoot at different ranges, mark your MOA's and go to work on your pc.
I'd suggest keeping with the b.c and adjust the MV to accommodate your hits, after all it's not about speed. I've found this to be a fail proof system even if the MV may sound a little off. Most guys like to publish the velocity for bragging purposes but that doesn't bother me one bit.
I just happen to use the Berger 210 in my RUM and when I tested the points of impact at various ranges, my Exbal software showed my velocity at 3090 fps, my Chrony was 85 fps off. Which do you think I'll follow?

yep... .gun)

 

[MuleHunter]

Also Berger bullets are a tested BC not computer generated so they are nuts on as long as your shooting them around the tested muzzle velocities of 3,000 fps. Your crono, or click values, or both, are off.

 

[bigngreen]

The Berger BC is almost rock solid and I would not touch it but look elsewhere. The HSM ammo I've ran out has been very close to published specs, I would be very suspicious if I had to tune it as much as you have but it could be possible. If it seems like your of about the same MOA through out the range but have to tune the velocity beyond what it should be then look at your turret adjustment value.

I set up a rifle and scope last week that was showing low at every range out to 1435, I could tune it up to be on out to about 1000yrds with velocity but then at 1435 it was not on, took everything back to the velocity I thought it should be, which the crony told me it was and tweaked my turret adjustment just .020 and ALL ranges to 1435 were spot on, not a little high then a little low but dead nuts on!!

 

[Tyler Holderby]

Thanks guys for the input! what do you mean by tweaking your turrets? how do you do it? thanks

 

[WildRose]

Thanks guys for the input! what do you mean by tweaking your turrets? how do you do it? thanks

I think he's referring to moving his initial zero point.. .

 

[bigngreen]

What I was referring to was changing your turret movement value in your program to match what the actual movement of the turret is. In my program I changed from .262 per click to .230 per click. Every optic needs proofed for turret movement value, it's not uncommon to have to tune it up a little.

 

[Tyler Holderby]

Any idea on where/how I can find my actual turret movement..Sightron 6-24x50 Slll SS??

 

[Bobcape]

Any idea on where/how I can find my actual turret movement..Sightron 6-24x50 Slll SS??

Get a long piece of butcher paper. Set it up vertically at 100 yards. Place a dot near the bottom edge and shoot a group. Dial in (and count) almost all of your elevation and shoot another group aiming at the same dot. Measure the distance between the center of the two groups. Do the math to find your true click value.
I.E. - dialed 112 clicks (28 MOA), distance moved - 27.25"
Click value = 27.25 / 112 = .2433"

Also a good opportunity to verify if your scope is mounted level. Take a piece of string and a weight with you. Check it before you move the paper.

Bob

 

[curiousaussie]

I agree with bigngreen and Bobcape.

I have one Nightforce that fits best with 0.094 mRad click value and another with 1.05 mRad click value. These inputs make the flight curve fit over all distances rather than either up close only or out wide only.

Try the butchers paper trick, it can yield good information.

Cheers,

Matt

 

[Tyler Holderby]

Sounds good thanks guys!

 

[coues7]

Awesome thread.