not sure about my ele. estimates need advice

[Savagebien]

i went to shoot at a nra range with silhouettes at 2,3,4, and 500 meters yesterday, and i had just plugged in my bullet,my ASSUMED velocity, and other stuff into jmb and wrote it all down. i got there, hit 200 and 300 meters just fine, then couldnt get 400, no one could spot where it was going, and i couldnt either, so i ended up goin for 500 meters, with some spotting there we got it dialed and then i hit it several times. BUT, my ele. adjustment was 12 min to start with at 500 meters, ended up dialing it on at 9.25. so i guess thats y i wasnt hitting at 400 because i had dialed 8.25 for that. SO, i got home and kept adding velocity in jmb untill it gave me the right amount of moa for 500 meters, the amount i was using. so could my rifle actually be shooting the 350 fps more than what the sierra load manual estimates? or is it another variable? with this load the sierra manual estimates 2800 fps, but there was less drop than that... so what do you guys think? thanks!

 

[royinidaho]

The proof is always in the field data, as that was the way it was, that day.

The input used for scope height could also make a bit of difference.

Keep good logs of each shot and it will all come together one of these first moments.

 

[Ridge Runner]

my guess would be a combination of faster MV and higher than published actual BC, In order to predict your POI at various ranges you must know either the exact MV or the actual BC, if you have one you can figure the other, but not both(I cant anyways).
RR

 

[Savagebien]

awesome, thanks fellas, i reckon more shooting is all that can be used to solve this one!!!! im working on some loads now, will be just like what i was shooting yesterday, but with new rem brass VS the old federal leftovers from ammo i bought, think velocities will b pretty close?

 

[royinidaho]

Check the weight of the Fed brass against the Rem brass.

The heavier of the two will give higher velocity and higher pressure if my experience is consistent.

 

[robbor]

elev

I did the same thing a long time ago. I took the 22mag out and printed up a rough drop chart.
I sat on the top of a hill waiting for rabbits. With an unaccurate chart and not taking into account for my downward angle I was shooting over the rabbits to start so much that at max scope power the bullet hits were not even in the scope.

 

[Savagebien]

my poor lee scale doesnt weigh enough for the cases.... so that comparison is out. i guess i will find out when i shoot again, and by the way the rem brass i got, bag of 50, had 52 in it, that ever happen? lol

 

[jwp475]

and by the way the rem brass i got, bag of 50, had 52 in it, that ever happen? lol

It happened to you, so yes it happens..

 

[Savagebien]

haha, thanks, i just poured the federal case full of my imr 4350, and then dumped into the new rem brass, and the rem has more capacity, so im expecting less pressure now, and thus less velocity, so i'll c how things go, hopefully this weekend!!!