I only have a few rounds through my 6.5CM RPR and my PR skills are highly limited but have a question about strelok or maybe other app calculators for PR shooting.
I tested what the RPR likes and was getting 0.35MOA at an indoor range with 147 ELD Match (140s were a close second and the 129SST sucked). I'm using a Burris XTRII 4-20 SCR mil scope with a thunderbeast on the end.

I toss all my data in my strelok Pro and head out to my parents property which I can shoot out to about 620 yards. I'm out shooting in dead calm weather starting at 300 yards on a 6" plate and hit w/o issue but expecting it to be more dead center.
The next shooting position after 300 is 550 and 620 (two different targets). I dial based on what strelok is telling me but I'm way off. Shots feel fine just not connecting and i'm putting them in snow so not 100% where they were going. I don't want to waste ammo so I figure something is a miss in strelok and call it a day.
I feel what I have in strelok is pretty solid so I'm trying to figure why I'm way off and best way to problem solve it.

(I shoot 3gun so you know I have no PR game what so ever but w/ my 16" rifle w/ a leopold 1-6 CMR on it, and I was hitting 80% on an 8" plate at 420 yards the same day if that gives you a baseline of skill set)

Were you dialing wind? Holding?

What inputs? Post them up there might be something way off.

Chrono?

You are going to need to see where the shots are hitting OP..with that info on my AB ballistic program in my kilo 2400 I can true the dope, weather that is an adjustment to velocity or the bullets BC..

Basically I enter all my load info, range a target, using the onboard weather tools and AB program, then shoot and record the actual correction needed to get hits, then the AB program calculates the new dope.. for me it took my G-7 BC from .374 to .380 to get correct hits out to 2000 yards(as far as I have shot so far)....
Attached File

How did you determine the muzzle velocity? Did you use a chronograph or are you guessing based off some other data source?