How do I calculate my shot if 150gr bullet drops 30in at 500yds and I shoot..........

J

Jamie Young

New member
1000yds? I don't know anything about ballistics HELP!!!!!!!
I do know that my bullets drop around 3ft but I don't know exact velocities of my bullets.

[Edited by SodaPop on 12-24-2000 at 03:40 PM]
 
SodaPop, If you know the caliber, bullet size, distance and the drop you should be able to use the ballistic table to figure it out. If you don't have the tables available just post the information and any reloader will be able to help you out. Understand that is is just an approximation, and does not replace the accuracy of a cronograph.
 
Its a 30cal 150gr and I know from past experience that the bullet drops 30inches at 500yds. What else do you need to know? I want to know approx where the bullet will be at 1000yds?
 
A .30 cal. (.308 dia.), 150 grain boat tail full metal jacket bullet will be traveling approximately 3233 fps. at 100 yards. At 500 yards the same bullet will be traveling approximately 2307 fps. The drop at 500 yards shows to be 33.8 inches.

THe drop out at 1000 yards will be much more severe. My books only show out to 500 yards. Now there are ballistic programs out on the net that allow you to input all these variables. Doing it this way you can input the 1000 yard marker you are looking for. I will try and find one of the programs for you and post it here. I'm sure someone else will see this post and correct me if I have miss stated any information or they may have the location of these programs.
 
I prefer to keep it zeroed at 100yds for hunting here in PA. If you know any tricks I'm all ears? I am learning how to adjust my MOA out to 500yds and I pretty much know my adjustments out to there.
 
Here is a site that has several software programs that might help you. Some you need to download and some are web based. There are just so many variables that it makes it hard to work it backwards like that. You can certainly narrow it down and get it in the ball park as long as your information is accurate. Then there is always the human factor.

I hope this help you out.
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http://www.lascruces.com/~jbm/software/software.html
 
For a 150 grain ball bullet sighted in at 100 yards to drop 30 inches (from line of sight) at 500 yards, it would have to have a muzzle velocity of about 3650. It would then drop 222 inches below line of sight at 1000 yards.

This is pretty unlikely, unless you are shooting an awfully big artridge.
 
I shooting a 30/06 rifle and I have shot it aiming approx 3ft above my target at 500yds and hit it every time. It might be 34 or 36 inches not 30inches I don't know exactly but its not anymore than that. I have never used a Chrono so I don't know what my true velocity is.
Thanks Fisher and KLN
 
I have to point out that calculating the bullet drop is one of the easier tasks when shooting long range. You also have to account for any wind, a much more difficult task as a rule. You also need to conpensate for shooting up or down in elevation if you aren't shooting on level ground.
 
Yeah I am thinking about that JohnWill I just want to get approx drops and go from there. I'm trying to learn about this stuff in stages because I don't know all the terminology and the applications yet. The place I shoot 500yds has some pretty weird crosswind where the wind acually blows one way at 100yds and the other way at 500yds. I don't have a clue how to figure out the actual elevation of the target at 500yds but when I aim about 3ft about the target it lands on paper every time and usally right down the middle of the target. Maybe its luck LOL!!
 
Use a boattail Spitzer and sight your rifle for 3 inches high at 100 will put you dead on at 250 yards.

At 500 Yards hold a yard high but really you shouldn't try to shoot game at that distance with a 30-06.

I doubt you are geeting any thing better than 3000 fps out of a 30-06.
 
Wow, that's some load!

Fisher and SodaPop, I have to agree with KLN, for a 150gr .308 bullet to achieve 3233 fps at 100 yards means it's flying over 3600 fps at the muzzle (Speer ballistics table). All I can say is WOW, what powder and action are you using? I WANT SOME! As I looked through my Hornady, Nosler, Sierra, Speer, Hodgdon, Accurate Arms, IMR, Winchester, and Vihta Vuori load manuals, the best I could find for the 150gr bullets was 3000 fps at the muzzle for the hottest load (Hornady & Sierra), and most were somewhat less. Something just ain't right with that math, know what I mean?


SodaPop, with all due respect, I took your 100 yard zero, with the hottest .30-06 load, and the cleanest coefficient bullet, and crunched it through the Sierra Infinity Ballistics software, with an impact at 500 yards. This software has been pretty accurate, I've used it a lot for my 500 and 1000 yard tactical matches, taping the charts to the butt of my rifles. Take a look.

SodaPop1.jpg
 
Please give us more details.....

What is your load data and what bullet are you using? Are you sure about your zero range and the other distance? How high is your scope center above the center of the bore? It is pretty difficult to have an accurate "drop value" just by shooting a few rounds at 500 yards due to wind, inaccuracy of the rifle, etc., and sometimes it's hard to tell a drop of 30" from a 36" due to group size and eviromental conditions.
Considering a super duper 30-06 load of a 150gr SBT bullet (high ballistic coefficient), at 3100 fps muzzle velocity (high, but possible in a 26" barrel), with a scope mounted 2" high above center of the bore, and zeroed exactly at 100 yards:
Your bullet will be 32.7" low at 450 yards, and 44.2" low at 500 yards. It will be 333.8" low at 1000 yards!!
 
Now, that showed a 48 inch low impact from a 100 yard zero, no winds or elevation (pressure) variables added. Let's take that out to 1000 yards, going with the 3000fps 150gr Sierra MatchKing, best case scenario, because I don't know what bullet you are using, or it's velocity. I did it backwards, zeroing at 1000 yards, to give you both your 500 and 100 yard hold-overs. Note that the peak of the trajectory's arc happens past 500 yards, closer to 600 yards. Your holdover at 100 yards would be 36 inches. To make it a flatter trajectory, you have to either boost your muzzle velocity, or change your bullet's ballistic coefficient, or, preferably, both. Fun stuff! :)

SodaPop2.jpg
 
Good grief, lookit all the junk open on the taskbar when I did my screen capture! Talk about the marvels of modern technology...

SodaPop, I can easily change the parameters if you ever get some chronograph data, or share the load data you're using with us, to include your rifle's barrel length, etc.
 
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