Thread: Help with Ballistic D.O.P.E

Hi Team
Just wondered if there’s a simple fix/solution to the issue I’m having.
Quick run down. Im shooting a 18inch 308 with a Swaro scope using the 3dot coloured dial u system. Ballistic data app I’m using is strelock pro.
I’ve developed a new load and trying to figure out my data.
I have verified my load at 400yards by working backwards in changing velocity to get the correct amount of clicks required at that distance. In theory I thought the rest of my data should line up however when i shot at 500 I was 8 inches low which requires an extra 6clicks.
My question is how do I get my data to line up. Hope someone can understand what I’m trying to get across.
Thanks Matt. .

Best to calibrate that kinda thing at the furthest distance you can, no? The closer you are, the smaller the drops you are working with, and so the more a small bit of noise or error in measuring will screw you up further out.

Check your zero, height over bore, BC, and use the 500m drop to do your reverse calculations from.

Better yet, use a chrono. Must be someone nearby on here who can help you out.

Thanks @Pommy. Was going to be my next step was check against chrono . My data at 500 puts me 3inchs high at 400 so I’m a bit confused as to what step to take next to get it to line up.

What pill is it mate?

Swaro’s Z5s dial 0.975” per 1 MOA. They don’t dial TMOA or IPHY. You need to set up your ballistic app to account for this variance. My profile on my ballistic app is set to IPHY for the dial unit (1.000”) and then you set a correction factor which accounts for the 0.025” difference from the IPHY. Screenshot below should explain hopefully. Once the data entries in your app are all correct then it’s a matter of shooting target at said range and adjusting MV if required in your app to make your solution match your real world results. Shouldn’t be a huge change if you got a reliable MV from a good chronograph and all the data in your app is correct.

Watch some applied ballistics you tube video on truing or validation
Not sure if streloc has validation software.
Fudging stuff is a pretty slow way to do things with dubious results.
AB has comphrensive information and their applied ballistic apps is the best there is.

Sent from my SM-A226B using Tapatalk

Originally Posted by Kelton

What pill is it mate?

168grain A-Max

@stagstalker thanks for the info Il look more into that. I’ve got mine set on SMOA which I thought accounted for the Swarovski scope not being true MOA.
Cheers @andyanimal31 Il jump on and check some out. Yeah should have started with the chronograph just knew I was close and once I’d shot a group at 400 and 500 I’d be able to work backwards and work it out but not quite lining up like I thought it would.

Also double check your zero, make sure it's bang on what you have input into strelok.

I imagen your some where around 2450-2550? The 16 inch im using the 168 at 2420 and the 18 the 178 at 2477 with 2206h

Originally Posted by mattstr

@stagstalker thanks for the info Il look more into that. I’ve got mine set on SMOA which I thought accounted for the Swarovski scope not being true MOA.
Cheers @andyanimal31 Il jump on and check some out. Yeah should have started with the chronograph just knew I was close and once I’d shot a group at 400 and 500 I’d be able to work backwards and work it out but not quite lining up like I thought it would.

Yep found a utube video for strelok pro doing trajectory validation.
Make sure your zero is perfect before you start

Sent from my SM-A226B using Tapatalk

Originally Posted by mattstr

@stagstalker thanks for the info Il look more into that. I’ve got mine set on SMOA which I thought accounted for the Swarovski scope not being true MOA.
Cheers @andyanimal31 Il jump on and check some out. Yeah should have started with the chronograph just knew I was close and once I’d shot a group at 400 and 500 I’d be able to work backwards and work it out but not quite lining up like I thought it would.

SMOA is the same as IPHY. Shooters MOA / Inch Per Hundred Yards (1.000” at 100 yards). There is still the 0.025” variance when you set your app to that. Been through this with all my Z5s.

Did you confirm zero at the same time you shot 400 and 500?
Did you shoot 400 and 500 on the same day?
Did you account for aerodynamic jump?
How many shots did you use to zero, at 400, and at 500?

Originally Posted by mattstr

Hi Team
Just wondered if there’s a simple fix/solution to the issue I’m having.
Quick run down. Im shooting a 18inch 308 with a Swaro scope using the 3dot coloured dial u system. Ballistic data app I’m using is strelock pro.
I’ve developed a new load and trying to figure out my data.
I have verified my load at 400yards by working backwards in changing velocity to get the correct amount of clicks required at that distance. In theory I thought the rest of my data should line up however when i shot at 500 I was 8 inches low which requires an extra 6clicks.
My question is how do I get my data to line up. Hope someone can understand what I’m trying to get across.
Thanks Matt. .

Greetings Matt,
The first step is to chronograph your load. Otherwise it is the old garbage in garbage out. PM me if you need help with chronographing.
GPM.

@stagstalker thanks I will have a look in strelock and see how I can adjust this. Sounds like I need to take a step back and chrono load first of all then go from there. Appreciate the offer @grandpamac I have one that I will be able to use. @Magnetite I shot a tight 5shot group at 100 group so was happy sight in hight was bang on. I shot 400/500 on the same day. I shot 4shot groups at 400/500. I shot a 1.3inch group at 400 and then a 2.5inch group at 500 so was pretty confident of the height adjustment. I corrected via strelock then send another couple at 500 at clay targets to confirm the clicks I had adjusted was correct. s