Truing by MV, or BC?

[101stinfantry]

Guys, I'm a novice at the Ballistic Calculator. I've always let the solver true by MV, which usually alters my MV (acquired with a MagnetoSpeed V3) by quite a bit. My question is should I continue this approach, even though this calculation seems to be off as well? I'm using Sterlok +. Thank you.

 

[Danattherock]

Generally speaking I will change the velocity if I'm off out to 500-600 yards, past that I adjust BC. I'm sure there's a more scientific explanation but that's worked for me. I find the velocity I usually run as actual is good but the BC I tend to have to manipulate. Being sure all of your inputs are correct is essential and I would revisit that before you start manipulating velocity or BC. Sight height, for whatever reason, seems to be a common problem. Measure it and be sure its input is exact.

 

[101stinfantry]

Yep, I do need to revisit my environmentals, I'll agree there. I've done this several times, with .308 (which seems to be worse), and 6.5 CM. I'm usually pretty close to 600, but when I move to 800 I'm off by quiet a bit. Like I said though, I'm a BC novice, and computer idiot generally. Lol!

 

[Danattherock]

Based on what you said above your inputs may be fine. I use the a b curve in the past but switch the G7 last year so I could manipulate the BC which seemed to be required quite often. As an example I just bought 2000 105 hybrids for my second Dasher barrel I just put on. The BC had to be changed 15 points, from the previous lot of 2500 from barrel #1.

 

[Dthomas3523]

If all of my environmentals are imputes correctly, I take the approach of I don’t care what I need to tweak to make the data work.

Get your good (keyword) verified dope to whatever distance you want. The more data points, the better.

Then tweak your sight height (trick that is starting to pick up steam, that you’d be surprised works well sometimes), mv and bc (sometimes only one of the three and sometimes all three....just depends).

Too many people spend too much time wracking their brain because they don’t think the calculator should need something (insert MV, BC, sight height) and are always dicking around with bad dope or calculator.

Just do whatever you need to make the dope line up in the calculator and that the calculator gives accurate solutions when the environment changes.

It’s been about 7 matches since I started taking this approach of just making the data line up (I only use a chronograph for load development, never for dope) and I can count on two hands at the absolute most shots I’ve missed due to a vertical error. In temps from 50deg to over 100+.

 

[Danattherock]

Solid advice above. Frank (Lowlight, owns SH) had a video on YouTube, Your Dope Disconnect, that turned a lightbulb on for me few years back.

Jist of it, hard dope vs hope dope, make the software your bitch. The bullet goes on a path, make the solver line up with the actual path whatever it takes.

For some reason prior, I was always scratching my head as to why the solver didn't line up.

 

[DocUSMCRetired]

Give this a try: http://appliedballisticsllc.com/Articles/Firing Solution Check List.pdf

 

[_Windrider_]

Based on what you said above your inputs may be fine. I use the a b curve in the past but switch the G7 last year so I could manipulate the BC which seemed to be required quite often. As an example I just bought 2000 105 hybrids for my second Dasher barrel I just put on. The BC had to be changed 15 points, from the previous lot of 2500 from barrel #1.

Truing a G7 is more difficult than G1.

 

[DocUSMCRetired]

Also, after reading that article I would highly suggest reading this: http://appliedballisticsllc.com/Art...rms – Improving on Ballistic Coefficients.pdf

 

[101stinfantry]

Thanks for the replies, and advice. I'm going to be going back through everything, and see if I can figure out where I'm going wrong.