Discussion in 'Firearms' started by ghrit, Nov 30, 2007.
Anybody have an idea where I can download free external ballistics tables for AR type rifles?
Have you tried Guns & Ammo
Lol, when I saw ballistic table I imagined a kevlar or hardened plate table. Just in case you needed to tip it on it's side and use as cover.
How about going to the remington website and looking at their .223 bullet drop specs ? I think they go out to 400-500 yards.
Thanx RH and Hartage, will try them both, probably tomorrow night. Gotta pack up a pile of stuff to head up country tomorrow. A whole lotta lead goin' on mongst 6 or 8 of us.
If you don't mind the old fashioned way, the Hornady book #2 is nothing but ballistic tables. RCBS has a calculator, but you have to pay for it. The other sites given sound good.
G&A failed me totally, Remmie had some good dope, but limited to Remmie loads. May be close enough for my purposes. I'll check the Hornady site and a few other bullet mfrs as well. I think I can get what I need if I can come withing minute of large pumpkin at a battle range of say 200 meters.
Give me the load data you want to check on and I will get the data for you from either my hornady book or RCBS program.
That should be a cakewalk. The round itself is not going to be the limiting factor. The difference in bullet drop brand to brand will be miniscule. Actually the bullet drop should be almost exact brand to brand. Only difference will be speed coming out of barrel bullet weight and type being equal. Accuracy will be another matter though. But 1 moa would be a 2 inch grouping at 200 yards. Hitting a pumpkin at 200 yards should be a cakewalk with just about anything that can acheive 1moa. Lets say a large pumpkin is 8 inches in diameter. 200 yards a 4moa grouping should hit that just fine.
Difference between brands in the same bullet weight is not going to be much of a factor if all you want to hit is a pumpkin at 200 yards. Every other factor (ie gun itself, shooter, rest stability, etc) will affect it much, much more. Never tried an AR though for precision shots so can't give you any tips. Good luck on your quest.
Im pretty sure that if you are zeroed at 100 yards then out to 250 or 300 yards you wouldnt even have to consider drop to stay within 3" or so. It has been a while since I looked at a balistics chart on .223 but IIRC the drop at a range of 200 yards was less than 4" (IIRC it was closer to 2" then increased sharply out around 300 yards) and given the difference between the height of the sights and the bore, if the lines cross at 100 yards and the trajectory were straight then the round would hit high a distance equal to the difference in the 2 lines at the gun. So, if it drops say 3 inches in 200 yards then you should be back at zero or real close to it.
Depends on the weapon. I am assuming that we are talking AR, and if that is the case, then a 25 yard zero puts you dead on at 250, with iron sights. Militarily speaking of course!
55 gr Wolf 16 inch bbl
40 gr Federal
62 gr Remmie
Bbl is 1:9 which probably won't stabilize the 62, but that remains to be checked out.
TIA Sniper --
After I get done with the daily routine, I'll have another looksee for on line data at Hornady, maybe Speer as well. (Sore back today, helped a buddy clear some brush as he called it. Yeah, right!! 10 inch diameter brush, with puckerbushes thrown in.)
BTW, for MN guys, the complete knowledge on 7.62X54R exterior ballistics is at 7.62X54r.net. Tables and graphs for just about all known makers.
Need two more things before I can compute. I need the velocities for each. If you don't know them, I will use base standard data. I also need to know what distance you have or want the gun zeroed at.
Let me know and I have the data ready, just to much to post without those specifics.
Velocities unknown, not printed on the boxes. Therein lays the rub, I can get the velocities of any, if I have the trajectory for any one that is known, it is a fairly easy calc. Standard will do absent exacts, I can't find any data that tells me what to assume.
If I have the drop tables (or trajectory graphs) it's an easy figure for point blank range knowing the offset for the sights. Gravity rules.
Much grass, Sniper --
I'll get started, did you have a range you want as your zero set?
Using a 100 yard zero on a 40 gr. bullet, with standard pressure at sea level, with a 1.5" scope or sight height. 50 yd: -0.1 100 yd: 0.0 150 yd: -1.5 200 yd: -5.8 250 yd: -13.8 300 yd: -27.2
Based on a 250 yd military battle sight zero and other info the same: 50yd: 2.9 100 yd: 5.5 150 yd: 6.6 200 yd: 5.2 250 yd: 0.0 300 yd: -10.7
100 yard zero with a 55 gr. 3200 fps. 50 yd: -1.5 100 yd: 0.0 200 yd: -3.0 300 yd: -12.0 400 yd: -29.3 500 yd: -58.2
The book doesn't have a 250 since it goes into hundreds of yards, so you will have to extrapolate for the 250 from the 300 yard zero. 100 yd: 4.0 200 yd: 5.0 300 yd: 0.0 400 yd: -13.3 500 yd: -38.1
62 gr with military velocity of M855 of 3000 fps with a 100 yd zero 100 yd: 0.0 200 yd: -3.5 300 yd: -13.3 400 yd: -31.6 500 yd: -61.2
62 gr. with 300 yard zero 100 yd: 4.4 200 yd: 5.4 300 yd: 0.0 400 yd: -13.9 500 yd: -39.0
I hope that helps. My laptop with all my reloading data on it broke on me today when I was firing it up, the on/off button went sproing and I can't get it turned on. When I do, I can get exact data from my RCBS calculator.
ghrit is interested in hitting a large pumpkin at 200 yards. The trajectory of a .223 is flat enough that if zeroed at 100 yards you'll hit a large pumpkin at 200 even just guesstimateing or even still using the same zero at 100. Such a large target has so much allowable slop that calculating trajectory based on finite points seems moot.
Home free, and many thanx. That data will get me where I think I want to be. Printing as this is hunted and pecked.
I have a better idea than all this math. Just get a bigger pumpkin.
Or you can use tracers, and walk them to the pumpkin.
But the punkin I had in mind is on a set of shoulders --
Actually, I just got my ballistic calculator up and running, figured out how to bypass my on/off button. I will give it a whirl for ya.
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