Range Report Help with dope 6.5x47l

[pitdog85]

So yesterday was trying to establish dope/velocity by shooting at 500m. Quickload predicted 2750fps with my parameters so I put that in ballistics AE which gave me a hold of 3.2mil. I have my sight height correct at 2.2inches. Weather was entered from my kestrel. Anyway as you can see from my target the first shot that is low and right with the 3.2mil hold. So I adjusted velocity and held 3.5mil which was the second shot. This is where I get confused I held 3.4 mil for next 3 shots one which was the closest to centre of target than 2 that were high and higher than the 3.5mil hold.

what do you think my dope is based on these results and I think my speed is closer to 2700fps based on the drop

 

[JTJACKSON]

At 500 y/m muzzle velocity has to be pretty far off to give you a hold that is terribly wrong. According to strelok pro, at 500m a .3 mil difference is nearly 100 fps for my 6.5 CM (3 mils at 2820 fps as opposed to 3.3 mils at 2727 fps. .3 mils at 500 meters is just shy of 6 inches). The farther you are from the target, the more separation you will get between the predicted holds by the computer and actual impacts.

Watch the online training video Gathering Dope for Your Ballistic Solver. Tells you what you need to do.

Also, shoot a group without changing your hold, then check and record your results. Don't chase the impacts from shot to shot.

 

[308pirate]

Do you have a chronograph, or know someone with one?

 

[pitdog85]

Do you have a chronograph, or know someone with one?

That is a negative for both

 

[demolitionman]

What's alot easier way to do this is to find a berm or backstop that you can spot your misses on. Lay some clay pigeons down(I like 600yards for this). Shoot at the clays until your dialed in enough to hit them reliably. Then fine tune your dope by shooting the clay shards.....dont chase your missed shots all over the place like already stated. Doing this kind of work is better suited to calm days.

 

[pitdog85]

I have access to only 600m max so I will give that a go next time. I was mostly confused about how the 3.4mil holds were both higher and lower than the 3.5mil hold. I will do what you guys say and shoot a group holding same elevation and see what happens. It probably doesn't help that mirage was boiling heavily (mid summer in tropics here) and the target was fairly blurry

 

[308pirate]

That is a negative for both

I suggest buying one

 

[308pirate]

It probably doesn't help that mirage was boiling heavily (mid summer in tropics here) and the target was fairly blurry

Yeah, don't do that again. A boil makes the target seem higher or lower than it really is with obvious results.