Take it to General Discussion. Tj

For those interested in what we were talking about, here's a good explanation: Hornady External Ballistics

The loading for a curve works well for a lot of applications. MY hot 20 Tacticals and 204's are about identical and Arther ranges that I shot PD's at (under 300 yards) a hot 40 grain 223 will have very close to the same flight. I like to do a Point Blank sight in with most of my rifles particularly if the stepson or his buddies are using them. Plus or minus 3 inches is about right for PD's with their skill level. They don't go for purposeful head shots like I do but they do get to see some red mist!!

The variable height deal can sure cause some havoc when you get use to a set of ballistic parameters. Luckily I only have three heights to deal with, my AR's (flat tops various ring heights) my CZ 527's (identical ring heights) and my 700 Remingtons (identical ring heights). Once I get those straight I am good to go. We four different rifles for PD's last time and all were within 2 inches of each other at 250 yards so it made it a lot easier once you got past 100 yards or so for hold over/under.

I like the Trig stuff for angular shots but like you a crib sheet is nice. I have to do the mental gymnastics at matches when it is unknown distance stuff giving it a WAG for range but I try to have a flat enough round that short of 350 yards an 8" plate is going to get hit somewhere for a score.

Greg

Well, I can assure you have that match loads thing way down better than I. I'm struggling with it. The calculator helps as I can compensate some with BC using the calculator to help in bullet selection. At least, I think that's where my variance is coming from. I'm not for sure? I do a two point shoot verification of my curve (and not really good points even typically 50/100). I then adjust the calculator to match, typically bullet weight and BC. I consider fps a given since I chrono. That's how I get my crib sheet.

I'd love to get with you some day just to pick your brain.

I'm afraid I'm still long on the math and short on the skill experience. I'm a long time iron sights guy who just turned to optics due to my age and optics sorta pushes you to shoot further out.

I was an iron sights long distance shooter, actually was very good with the M203 as a kid, and am a boater so a fair judge of distance. Its once I got into this threading the needle that my skill set on that is way too little. I have the need now to get far better on distance than just my judgment. Its not like I have a man (pretty well known average height) out there as a guide. If I told you what I was using now to judge distance, it would blow your mind. I'd love to get your thoughts on methods when we find the time, possibly another thread.

As it is, in this thread you and the OP have me on new quest. It never crossed my mind for some reason to use the MOA on a Red Dot to judge aiming point at distance. As you can probably gather from liking the Russian style reticles, and graduated recticles, that's probably something I'd be pretty good at.

I've always just used them close in and tried to match the MOA to bullet spread and not anything else. Who knows I might become a major fan.

Tj

Shooting across two points is great. The further apart they are as in 100 vs 300 will give you a pretty accurate read. There is , of course, the bugga boo of the shooter that always figures in the equation. With your experience knowing your abilities will at least keep your mind at ease when the groups get printed. Ability to shoot at the target with consistency comes with either extremely great natural talent or blood, sweat and tears behind the trigger over the years!!

The math stuff is just a logical progression for me as I am a numbers guy in my head. The book "The Ultimate Sniper" by Plaster got me turned on to Mil Dots. I had used the standard Leupold Duple reticle for years for range estimation and was pretty good with it given known target size like an IPSC Milpark.

When I was selected as an M/O instructor the math really kicked in. My trainer was an ex-Army sniper instructor and taught all over the world on a contract basis. He was a young fellow that was into high speed low drag stuff like sports cars and sniper rifles. he specialized in night vision R&D stuff as a side job. His credo was, "If you can put the math on the gun you can hit anything." After two weeks he had me convinced that he was right. I lived and breathed MILS and MOA for 14 days and fired over 2000 rounds getting it down at unknown and known distances. He tested us in all three permutations of the MIL set up and my calculator buttons were much lighter when I finished.

I guess I should apologize to the OP for wandering around like a scared jack rabbit and hijacking his thread. Based on that he has my blessing to steal the next one I start!! I think the whole board has something to kick in on range estimation. I'll start a threat tomorrow on marksmanship (I gotta think about what I want to say!! LOL)

Reloading for task is great so maybe we can roll it in together with some "assumed" data variations.

Greg

Wow! This is the stuff I am looking for. What are these crib sheets you speak of?

Check this link out. It's a great tutorial with in depth explanations of MOA. It even breaks down the math.


I stopped using the free online version and actually purchased the software. Great little app.

That is a great program. Like I pointed out earlier we gave a copy to all our aspiring M/O's in their training activities. I fielded phone calls and questions from as far away as Hawaii with my students following their two weeks of training.

And for JasonK94Z a crib sheet is basically just our drop tables printed up full size for reference and then shrunk down to needed info. I print drop tables in 25 yard increments to my MAX range but the "crib" sheet I use is made up of the dope for much broader spans. I'm looking at one here on my 20 Tactical AR and the print out sheet that I have taped to the bell of the scope shows me the drop table at 100, 150,200,250,300,350,375.400,425,450,475 and 500. My DRIFT table shows a 10 MPH crosswind at 100,200,300,400 and 500. I can do the incremental math in my head for the in between ranges.

On my match guns I put it on the bell of the scope and will also tape a slightly expanded one on the stock with a lot bigger print so I can look at it in a hurry if I have a question as to where to hold on a target way out there.

Here is a program that is free that you can use to print out the drop/windage in Inches, MOA or MILS
JBM BALLISTICS You can extract the data as you need it and do your own crib sheets with it. There are several free programs you can use to generate the data out there.

Greg

I cannot be alone in hoping you guys throw a clinic somewhere someday. Many of us have a similar facination with balistics but little chance to use the practical "shooting" side of it.

The ballistics thing is just a paper chase that you play until you get to put it into practice. I play "what if" with the charts a great deal trying to find out what that extra 100 fps will do on a given bullet (99% of the time almost nothing!!) I also use it to make decisions on what cartridge to use for a given application. varmints (as in PD's) don't need a lot of energy but they do need a lot of accuracy. Big game (of which I never get drawn for) need more energy but surgical shot placement is not so important. Something the size of a small soccer ball is not that hard to hit even way out there.

I recommend a bit of social networking and finding a farmer somewhere that will let me set up an informal range for long range work. You might check with the local gun clubs that might have a 200+ yard range that you might get to use. MY BOP credentials let me get on a lot of 600 yard ranges for my snipes and being where I am I have the whole state of Arizona deserts. The place is like a free fire zone in many areas just down the road from me here in Phoenix.

Any questions you all come up with can get hashed out here or direct e-mail. TJ is VERY good at his thought processes on a very broad subject matter. I can get by and usually have some basis for my theories but there are some other guys on here that time and time again just flat amaze me with their rational common sense approach to problems. Not a lot of sacred cows to gore here so we can all learn.

Greg

this stuff confuses me too

The thing in total can be a real challenge. If you break it down to small areas like MOA and how they compare to inches, MILS and how they compare to inches and MILS and how they compare to MOA at different ranges for all three equations you will get a god handle on it.

If there is an area that is real confusing just pipe up on here and TJ or I might be able to get you to have an epiphany over all the math applications.

I live and breath this stuff and always like helping others learn.

Greg

As a new person to this amazing hobby, I do have to say it can be a bit overwhelming. From equipment selection, to the science, and to shooter skill development. I am starting to get into long distance shooting and have discovered like many that I am going to have to start somewhere. I have been reading a lot about reloading but that is a whole subject in itself, especially learning everything about the bullets etc. Question is, where to begin? Do you start by studying the ballistic science, then start studying the tables/charts etc? Sorry for the dumb question but clearly I am a newb.

Hardly a dumb question. That is one nice thing about the Internet. You have access to all sorts of data that I had to hunt up in books etc. The chance to mine other shooters experience is invaluable. Remember thought that all that glitters is not gold and common sense and maybe getting data verified through a couple of sources is a good idea.

I'm pretty much self taught but I have been doing things at a higher level involving ballistics for a tad over 35 years at this point. My initial source to get me going was the Sierra loading manual with the drop tables for various bullets at various velocities. I got a good feel for what extra velocity does and the back and forth of ballistic coefficients became clearer as i analyzed what I was looking at. It also gave some great info on external ballistics (action of the bullet from muzzle to target - pure math) internal ballistics (action of the bullet from case mouth to muzzle involving pressures etc - physics) Terminal ballistics is the action of the bullet as it strikes the target and pases on down through the target media. (Lots of variables - real world stuff)

The Minutes and Inches thing are virtually interchangeable in the reel world so that is not that hard. Conversion back and fourth is pretty simple once you find out a MOA at 100 yards is 1.047 and expands as the range expands. 200 yards makes a MOA of 2.094 inches. 250 yards an MOA is 2.6175 etc.

The MIL stuff I learned from reading and setting down with a calculator as I had to understand it in order to teach our snipers in the BOP. I was a whiz at ballistics just needed to learn what these funny little dots did inside the scope and what good they were. The book "Ultimate Sniper by Plaster covers this very well. I started buying Mil Dot scopes for my varmint rigs and am pleased with how they work out. Big targets , say 6' tall, become a piece of cake way out there when you combine Mil Dots and a good proven drop table. I think I gave a link earlier for some ballistic table stuff so you can run some numbers in the set up and compare Mils to MOA and inches and look at how the B.C. makes a difference down range. TOF (time of flight) is used for calculating leads at various ranges and it is truly amazing how well that works once you get in the groove using that calculation.

Shooting is a learned perishable skill that takes time. I learned with a 50' rifle range in my basement as I grew up. Ballistics is a science that done right will assist you in making hits at any doable range. The actual I grew up. I kept on shooting air rifle on gophers and stuff for years and that is what got me into the realm of "adequate" marksmanship. As the skills develop so will your attitude about what you can do on demand. It has been invaluable for me on the game fields and in matches. I've always believed that equipment should never be an impediment. Get the best you can afford for the job at hand and learn to use it like it is second nature. I have never lost a match because my stuff wasn't as good as the next shooter and have never missed a prairie dog because the gun wouldn't do it. (Well some big group guns don't help!! LOL)

Get some manuals, look over some tables and run a few what if scenarios on the computer programs out there.

Questions?

Greg

PS: And I am serious about the questions. TJ will chime in here a bunch to so don't take everything I say as the "one true way" to nirvana!! - G.