Range Report calculating bullet drop at a known distance.

[oneshotonekillusmc]

i was wondering if there is a formula that exists that allows me to find the bullet drop at a known distance? one that computes your tempature,spin,barametric pressure allowing you to find an accurate drop in inches or MOA. the part i cant figure out is how to find the TOF with Drag that includes those veriables. I wanted to know if any of these formulas existed so that you can create this on the fly without ballistics software.Due to the ever changing effects in the field.
Thank you.

 

[Lowlight]

Re: calculating bullet drop at a known distance.

Why wouldn't you just use JBM online and print the range card.

you can then laminate it and keep it with you. All your dope for every distance at your fingertips with no long hand math. Of course there is a formula but it would require much more time & effort than doing it ahead of time and printing it.

Prior proper planning and all... most carry their data with them. Plus is that what a log book is for ...

Here Lindy has an article on making a card using Density Altitude.

http://www.arcanamavens.com/LBSFiles/Shooting/Downloads/DA/

 

[BobinNC]

Re: calculating bullet drop at a known distance.

Sure try this:

JBM Ballistics

Create as many drop charts as needed or desired for the day, based on that days weather conditions, then just print them out.

They have many calculators: For trajectory, drift, point mass, range cards, DA, stabilty, just to name a few.

 

[Greg Langelius *]

Re: calculating bullet drop at a known distance.

The tab at the bottom of the chart provides a drop/drift table that can be printed out. I trim it to its outline and overlay it with a length of clear postal packaging tape. The overlap is pretty ideal for simply slapping the chart onto the rifle's buttstock, just below the cheek weld.

I set mine up with 50yd increments out to the transsonic range, and have two for my LR guns, chart alongside chart, for two preferred loads, one zeroed at 200yd, and the other showing drop/drift plots with the same zero data, including the difference in zero at all distances, including 200yd.

For example, my .280s have charts for Nosler 120gr and Nosler 150gr loads. They don't vary that much up close; but out where the .280's reach makes it a significantly better chambering, proper drops are useful. What I really admire about the chambering is the way it makes such great performers out of lighter weight bullets that generate less recoil. My philosophy about reaching out and touching makes a large allowance to doing it without needing to bring a big-league shoulder basher to the game. If I ever get to go back to 1Kyd shooting, it will be a .280 that carries that mail.

I zero to one load, and plot drops for the other with the same scope zero adjustment. This is to accomodate different drops for the two loads without needing to readjust the 200yd zero datas back and forth.

Greg

 

[jbailey]

Re: calculating bullet drop at a known distance.

If you are looking for a nice algebraic equation that you can simply pull in a few variables in on the fly w/ a hand-held calculator, forget about it. The underlying math is extremely complex and would take hours to do long-hand. If you really want to go down this path, buy Exterior Ballistic by McCoy and review your college math books. I enjoy doing this stuff at home in front of my computer, but it never goes to the field with me.

 

[RayDog]

Re: calculating bullet drop at a known distance.

I'm with the others on this one. Why would you need to do this in the field? I keep a 7000AD card on most my rifles and can adjust as needed

 

[Suasponte]

Re: calculating bullet drop at a known distance.

Terry