ballistics calculator help

[shootingcharley]

Ballistics Calculator’s

Hi all I would like to know if anyone uses a ballistics calculator that works? I have tried a few and the figures just do not match up to the figures from just going out in the field and trialling them?

Here are my specks; if someone can run me off a chart I would be most grateful

 

Bullet Diameter .204

 

Ballistic Coefficient .287

 

Sectional Density 0.134

 

Bullet Weight 39g

 

Muzzle Velocity 3722 FPS

 

Zero Range 100 Yards.

 

Scope Height 1.5”

 

MOA 8

 

shootingcharley

[Gunsgobang88]

Ballistics Calculator’s

Hi all I would like to know if anyone uses a ballistics calculator that works? I have tried a few and the figures just do not match up to the figures from just going out in the field and trialling them?

Here are my specks; if someone can run me off a chart I would be most grateful

 

Bullet Diameter .204

 

Ballistic Coefficient .287

 

Sectional Density 0.134

 

Bullet Weight 39g

 

Muzzle Velocity 3722 FPS

 

Zero Range 100 Yards.

 

Scope Height 1.5”

 

MOA 8

 

shootingcharley

 

Hi Charley,

 

Just run your figures through BulletFlight on the phone, what info do you need?

 

Cheers

 

Alan

[shootingcharley]

I would like a drop chart from 150 yards to 500 yards if that is possible at 50 yard intervals

 

Thanks shootingcharley.

[Gunsgobang88]

Hi Charley,

 

I have run your figures through BulletFlight and they are similar to those from Ronny using the Nightforce ballistics calculator. They vary (slightly flatter shooting) by a maximum of .15 moa. This could be because the NF calculates to the nearest .25 moa while Bulletflight are to the nearest .1 moa. The figures for 500 yards are:-

 

BulletFlight - 500 yard drop 33.8", 6.4 moa elevation required

Nightforce - 500 yard drop 34.4", 6.5 moa elevation required

 

Nothing much in it, hope this helps,

 

Best regards

 

Alan

[Double0gorgeous]

This website is your friend plus its free

 

http://www.gseven.com/ballistic-program

[Guest richness]

Well just use the figures from the field - they'll always be more accurate.

I find the calcs pretty marvellous for working out windage but i only sue the drops from them to get me in the ballpark if i don't have a field-observed click to use.

Also, in your case you will find from field testing that the BC of the 39SBK ain't .287 mate... not by a good way IME

If you really want to use the app for drop, try first adjusting your fps to match the empirical values you're seeing in the field. And tweak the BC down a bit (try .25) and try to get them to match. But remember that whilst you're doing all that (and it'll never be good enough to say, shoot 500y rabbits first shot) that you could simply be shooting at those ranges and noting down the clicks you really need, knowing they'll be inch perfect in the future.

HTH Rich

[brown dog]

Well just use the figures from the field - they'll always be more accurate.........................

 

you could simply be shooting at those ranges and noting down the clicks you really need, knowing they'll be inch perfect in the future.

HTH Rich

 

No!!!

What you're describing is crap in crap out. Most ballistic programs properly set up will absolutely be spot on; and a far better solution than 'what happened last time I shot at 500 (an approach that simply can't allow for different ambient temp and different air pressure etc,,,, unless your dope happened to be recordde on a day that was somehow exactly the same as every other day ) The belief 'field data is better than properly done ballistic prediction' is not correct - it's all about correctly modelling the whole system.

 

Aaaagh!

 

 

Ballistics Calculator’s

Hi all I would like to know if anyone uses a ballistics calculator that works? I have tried a few and the figures just do not match up to the figures from just going out in the field and trialling them?

 

 

Charley - 99% of them work ...........you just have to put the right info in (and, obviously, be able to shoot consistently from occasion to occasion)

[Guest richness]

Fair enough BD we'll certainly have to disagree on that one my friend. I stick to my post entirely but respect your opinion mate

[brown dog]

Fair enough BD we'll certainly have to disagree on that one my friend. I stick to my post entirely but respect your opinion mate

 

 

I'll convert you...

[Guest richness]

 

I'll convert you...

 

lol OK, i'll rephrase. I know you do the drop charts and I hear they are absolutely spot on.

From the layman's POV, this is what i've found:

you need exactly accurate fps

you need the height above the bore perfect

to know your exact zero

to know the BC perfectly (and it is never what it should be) and with G1 BCs, well it's a joke normally with all the different speed ranges etc. With a decent and well-known match bullet with a reliable G7 maybe...

 

THEN, you can indeed process this info and get great figures, I don't doubt it

 

BUT on a windy-arsed hill in the middle of nowhere, quickly knowing that you needed x moa at 677y is a mighty mighty useful start. Now i know i said "inch-perfect" and that was probably a bit keen. But it isn't going to be whole moa out and calcs can easily be that far out. Now yes I know the right info will give the right results but it takes a lot more finding than using empirical notes from the previous shots and then allowing very slightly for today's specific conditions. This is just my tried-it-in-the-field perspective and I have 100% most definitely ended up going for apps for windage (no crossing twice over the sight line etc) and empirical clicks for drop, with a little on the day tweaking to correct for the ambient x y and z

 

You may convert me yet - indeed it would be very handy sometimes, especially when i've just changed load and want to get cracking

[Scotch_egg]

Having shot out at distance on my ground I can certainly concure that day to day my figure's differ.

 

 

Even on the same day morning to night I see a change.

[Gandy]

To throw my two penneth in, I'm still very much the beginner but slowly learning. I would make the following observations just from how I've learned over the last 18 months of shooting at longer ranges.

 

1. I'm sure ballistic programs are accurate but as BD says garbage in Garbage out and I'm only just learning the interactions and affects each element has. My copy of quick load gathers dust.

 

2. Real life data is invaluable, I would more call it time and experience, more with wind than elevation. I have a few pieces of land where I can shoot out to circa 800 yards ish. One is flat with a hilside backstop the other is over a shallow rolling valley with various disused railway tracks. They have different elevational and windage requirements. This is due to the topography as Eldon's guns drops in the same pattern as mine buts a diff call diff gun but has the same pattern of changes.

 

3. To blow smoke up Mr Brown Dogs arse, his cards, based on real life data, albeit some of is average from a newby have got me on or nearly on target the majority of the time. This has been great as its taken a lot of the frustration out of things. I shall be updating my data soon now I've spent more time understanding my rifle etc.

 

If I were to give any advice I would say buy or make a gong. Punching paper is laborious and you get caught up in group size and not positioning. Hit or miss with a gong improves you quicker.

 

The net result of all my time over the last 18 months / two years, due to a poor shot by another, clean 280 yard head shot, first time kill on an injured deer. My foxings improved and I enjoy shooting at distance massively. I aim to shoot at 1000 yards for the first time next year.

 

This sites great for info stick at it.