Squeaky 135 Posted February 15, 2018 Report Share Posted February 15, 2018 Hello: I've learned how to use my mil scope to estimate range. I read Mr. Cleckner's book which has a formula (for yards): height of target (in inches) x 27.77, then divide by the number of mils filled by the target in your scope. I'll being using Federal .308 GMM 168gr. ammo. I understand how once you get a range estimate you then refer to a ballistics chart to see how much drop to compensate for. Obviously, the more distance, the more upward elevation you need to click into your scope. My question is how do you get a proper ballistics chart? What do I mean? Well ... for any given day you have different temperature, humidity, barometric pressure, and wind. Assuming you shoot at the same range all the time, the only constant is field elevation. I can imagine bringing a huge binder to the range for any possible weather condition. Folks don't do that. Of course, nowadays there are cell phone ballistics apps you can use on your phone. I ask what are any of those? However, I really want to ask if there are any "hard copy" charts available on-line - for average conditions I suppose. I don't want to rely upon a cell phone. I hope I'm posing my query correctly. I want to go "old school," but I don't know how one finds a chart given the different seasons and weather for a given day. Thanks. Quote Link to post Share on other sites
Doug Hartley 526 Posted February 15, 2018 Report Share Posted February 15, 2018 Google JBM Ballistics. Many of the phone apps use the same engine. Put in your info and print out a hard copy. I have Ballastic AE for my phone but I always have a hard copy of the basic info for my load in my rifle bag. Phone app is handy because you can put in actual conditions in the field. Doug 1 Quote Link to post Share on other sites
gunfun 3,931 Posted February 15, 2018 Report Share Posted February 15, 2018 + there are a couple of Apps that plug into a bluetooth weather station and automatically record that stuff. You would have to enter drop on the actual hit from your point of aim to give the chart offsets, but it automatally enters the other factors. Some of them are geared into hunting and at least on the East Coast keep track of land ownership and stuff like that so you can avoid making a hunting mistake. They kinda give a GPS overhead of your area, then you tap on your phone where your target is, and it tells you range and all your holdovers based on the prior ballistic data you've entered. Pretty cool, but I think I would prefer simplicity and a hard copy too. I link this video, because I would have mostly considered something like that to be a nuisance and an expensive gimmick, but he actually made it sound appealing, at least for the way hunting works over there. A couple of my friends use golf cell phone apps too. Same kinda deal. GPS overhead picture. Tap on your phone that the target is right here, by that tree, or whatever overhead landmark you can see in real life, and it gives you a range that is within about 5 yards of correct. If you are working up a chart, it is nice to have fairly accurate ranges. A laser range finder is nice, but most of us don't have them, and a lot of us who do don't always have them with us. Plus they are kinda finicky to get a good read on foggy days, or on objects with the wrong level of sheen. They need to be aimed as carefully as the rifle is, but aren't designed to be held as steady as a rifle is. I found that frustrating when I have tried to use them. Tapping on the phone app is easier, and less prone to error. Quote Link to post Share on other sites
jerry52 893 Posted February 15, 2018 Report Share Posted February 15, 2018 I have used a few but ballistic for I pad will give you all the things you are asking for. I have used the mildot for years just know that a FFP scope is the best. It is great for range finding just start building a object library so you can use your formulas. ( I always taped them to the side of my rifle) As for ballistic data most ammo manufacturing company's have the data on the box or web sites. However this will vary a lot as most purchased ammo is loaded by volume and not weight. To really get the best data for your ammo you will need a chronometer that you shoot accross to find your bullet velocity average ( as no round will be the same). Understanding bullet types is a must. WARNING this will move you into the wonderful world of reloading Hope this helped you looks like you are starting right Jerry52 1 Quote Link to post Share on other sites
HB of CJ 1,263 Posted February 18, 2018 Report Share Posted February 18, 2018 Excellent stuff everybody and thank you. Quote Link to post Share on other sites
patriot 7,197 Posted March 6, 2018 Report Share Posted March 6, 2018 You might get some ideas from a couple of articles I did back in 2005 for Very High Power magazine. 2005-1 and 2005-2. Back issues are available. (I get nothing for this) Titles: 50 BMG Trajectory Adjustments – Part 1” (Trajectory charts for various .50 ammo loads) by Douglas Ott 50 BMG Trajectory Adjustments – Part 2” (Trajectory charts for various .50 ammo loads) by Douglas Ott http://www.1moa.org/back-issue-vhp-info.html Quote Link to post Share on other sites
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