Help with a AR and 50gr hornady vmax shoot way low at 300????

fur-down

fur-down

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So i started shoot groundhogs more this year and wanted to shoot out to 300yds im shoot fiocchi 223 50gr vmax zero at 200yd 100yd im dead on too but out at 300yd im low by more then 10" im lost. Armalite m15/ 1-9 twice /2.5" scope high. can someone help plz?????
 
Say hello to gravity!!

I ran it through a ballistics calculator real quick and just guessing on your elevation, velocity, and some of the smaller details, I came up with ~10.5" off drop at 300 if you are dead on at 100.

Again these are just using "guessed at" numbers but if you got to ~1.5" high at 100, you could bring it to about 5.5" low at 300.
 
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I got that app called shooter on my phone but it say it should be 3" low at most but im new to the math side of shooting and probably got something wrong. What are you guys using???
 
Here ya go. Excellent ballistic program you can enter your data and see trajectory. Just vary zero range to get the desired +/- bullet path that fits your needs best, then take it to the range to verify.

Click on link and a black screen will come up w/message, "Opening external program". Give is a minute while the program opens, then enter your data:

http://ballistics.norma.cc/javapage_US2.asp?Lang=2#

Regards,
hm
 
I got to looking at my shooting app its right i was reading it wrong it say at 300 u2.9 moa what i thought it meant i should be 2.9" hight at 300 but no it means i need to click up 2.9 moa. I look at the bullet map it says i should 8.5" low. But i still think thats low for a 223 or not that flat. Honady ballistics calculator says im 9" low
 
No that's about right.... the 223 isn't super "flat" shooting... especially out of short AR barrels.

I'd even that bet with those numbers you're using a velocity that's faster than what you're actually getting out of your barrel.

My advice would be to sight it in at 1.5" high at 100 and then learn to hold over for the drop at 300. It shouldn't be more than 7" or so.
 
You need to know a couple things. What is the real velocity your load/rifle is putting out. Not what the box says. The box lies because the manufacturer uses a standard barrel, usually 26 inches. Shorter barrels equal lower velocity. They also tend to exaggerate their results. Your bore/scope height is also not the standard that the manufacturer uses, they use 1.5 inches. You really need to put some loads thru a chronograph (5 or six at least and take an average.) Then actually zero the gun in at 200 and then shoot it at 300 to find what your drop really is. The results will surprise you. Altitude and temperature will also play a role. Bright sunny days will cause you to shoot high, overcast or low light conditions will cause you to shoot low. My heartfelt suggestion is to just go out and shoot your rifle, A LOT, but after you do a little homework. I've been shooting for 57 years and I'm still learning. Also do a some research on "Point Blank Range". It works.
 
Thank guys for the help i was getting lost in all the number and math! Im going to go back out and put more holes in paper [img:center]
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No expert here but I don't how you can be dead on at both 100 and 200 yds. My thumbnail for 60 gr 223 is 1.5" high at 100 yds puts me pretty close to dead center at 200 yds and 7" low at 300 yds. That gets me close. But I'm not punching dime size groups at 300 yds like some of these guys.

Ballistic Calc
 
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2.9 MOA at 300 is around 9" you have to remember that 1MOA=1" at 100, 2" at 200, 3" at 300 and so on. All the math is hard at first but once you get it its fairly simple and quick.
 
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2.9moa sounds about right. My 53gr v max load is 2.7moa low at 300. My 40gr v max load is 3moa low at 300yds and 6moa low at 400yds. All with a 200yd zero
 
I think im starting to get it i was looking it all over 2day and fixed some numbers its starting to make since. So at 300 it now says +3.3 so i click up 14 clicks to be dead on at 300?
 
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Name: 223

BC: 0.2550 (G1) Temperature: 80.0 degrees Cant Angle: 0.0 deg.
Weight: 55.0 grains Humidity: 40 % Sight-In Range: 25 yd.
Caliber: .223 Pressure: 29.92 in. (stn) Muzzle Angle: 6.153 moa
Sight Height: 1.50 inches Crosswind: 5.0 mph TargetSpeed: 0.0 mph
LOS Angle: 0.0 degrees Altitude: 0 ft. Target Angle: 90.0 deg.
Sect. Density: 0.158 Air Density: 0.0731 lb./ft.^3
Air Density: 95.5 % of Sea Level



Range Drop Velocity Energy Momentum
(Yards) (inches) (ft/sec) (ft-lbs) (lb-sec)

0 -1.50 3240.0 1282.0 0.7913
100 3.12 2862.6 1000.7 0.6992
200 3.47 2514.9 772.4 0.6142
300 -1.72 2192.6 587.1 0.5355
400 -14.20 1895.1 438.6 0.4629
500 -36.44 1626.3 323.0 0.3972
 
Once you get the baseline for your rifle with a particular load figured out, use the "notes" app on your phone to store shooting data if you don't have DOPE book. I like to use my phone, because due to the nature of my job, it's always with me. Make sure you record free air temp when your shooting. Like was stated already type of day will have an impact on your vertical impact. You will really see this as summer wears on and the daily temps get higher, on average with a .223 you can see as much as 1" rise in poi for every 10 degrees increase. On the other side in the winter you will see your poi shift down as the air cools below your zero temp resulting in low shots. Fun stuff to keep track of.
 
Originally Posted By: fur-downI knew timp played game with the round but i never would have guess that it could be an 1" just from 40 to 50 degree

That's pretty extreme and not the norm. If it was, everyone would miss all the time.
 
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