Question on ballistic app data inputs

[jackwagon]

What you could do that is more precise is shoot groups at your 750yd range and note the drop.

Zero for 100 and then record the drop for each 100 beyond that. Or, if ammo and time is a factor shoot a few groups at 300 and 700yds. Then play around with Strelok to predict the velocity by matching the actual drops to a particular velocity. Normally we determine velocity first and use that to predict drop at various distances. This way you are doing it the reverse.

Kestrel's with Applied Ballistics have a feature where you enter the chronographed velocity, shoot at a known distance and notice the difference between the predicted drop and actual drop. Then return to the kestrel and enter this difference to fine-tine your velocity. This is because all chronographs come with a margin of error. The Chony I use states it can be up to 5% error. Add to that any further error from the way it is set up on the day and it's unlikely the chronograph is going to exact. 5% of 2,500fps is 125fps which is a fair error and might explain why your bullets don't land exactly where your ballistics program says they should land. I don't know if Strelok has a similar feature to Applied Ballistics and maybe someone else can chime in here.

But...the other guys are right, you will need a chronograph at some stage if you ever want to do meaningful load development.

So just to update since this original post was awhile ago. I ended up using 20 fps/per inch, sat down at the 500 yard bench, dialed in the mils listed on the Strelok app and took 3 shots that went to the dead center of ??? Since I couldn't see where they went with my 10x42 I dialed back to my zero. I had a holdover card from last range trip that was out to 350yds so using that and 3 more rounds I found 500. I wasn't able to get to the 750 yd bench as SAMMY SNIPER AND HIS SEAL TEAM must have made reservations for the whole day. Due to the 3 hour drive each way and trying to test 2 many things( by myself) at each range trip it is certainly a challenge, but im enjoying it. Thanks to all on here for your help.