Range Report Proper Use of the JBM?

[Doc Holiday13]

Well I've been trying to stretch my wings with my 6.8SPC. I don't have a chrono, but fortunately for me I just recently downloaded a ballistics calculator for my motorola Q so it help a lot. I input all my data with the numbers I found posted about the 6.8SPC and bullets I was using

I basically plugged different speeds with the weather readings from the day into the JBM calculator until it matched what I was seeing on the target. Based on what I was seeing on the target I'm throwing 90grain TNT's at roughly 2950 fps.

Is this right?

 

[9H_Cracka]

Re: Proper Use of the JBM?

what distance were you shooting? Unless you were at 525 yards or further then discrepancies in the data and actuals will not be apparent.

 

[Doc Holiday13]

Re: Proper Use of the JBM?

I was limited to 300 yards

 

[9H_Cracka]

Re: Proper Use of the JBM?

no way to really tell then - buy a chrono.

Even with a chrono and a program you still have to verify your data at and out beyond 525 yds if you want to have reliable LR data. Been covered here many times - the only real come-up data is verified come-up data.

 

[Doc Holiday13]

Re: Proper Use of the JBM?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NineHotel</div><div class="ubbcode-body">no way to really tell then - buy a chrono.

Even with a chrono and a program you still have to verify your data at and out beyond 525 yds if you want to have reliable LR data. Been covered here many times - the only real come-up data is verified come-up data. </div></div>

Methinks I need to push to get over to the 600 yard range

 

[Downzero]

Re: Proper Use of the JBM?

Chrono is damn close.

With JBM, I was within 1 MOA, though.