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Does anyone have or know where I could look up ballistic charts for a 16" AR15 with a 1:9 twist for 55gr. .223 rounds? I am trying to decide if I want to zero at 50 or 100 yards. I would like to get a ball park of the trajectory, so I can save the ammo for fine tuning not guessing. All the info on .223 that I have is for a 24in barrel. Thanks for the help.
 

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http://www.jbmballistics.com/~jbm/cgi-bin/jbmtraj_drift-5.0.cgi

You can use this site to figure your drop out to 1000 yards. You need to know the BC of the bullet you're using and the velocity.

Even with a chart it's going to be a guess to start with and you'll change it as you test it on the range. If it were me, I'd sight it in for 100 yards and work up a drop table from there. Published velocities and BC numbers are seldom accurate.
 

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Thank you. That is a very handy site. That gives me a good idea of where to start. I went out this afternoon and zeroed at fifty. At 100 yards I was .5" high and at 25 yards I was -1.7" The link you gave showed -1.5 at zero and .6" at 100 yards if zeroed at 50yds. Pretty impressive. I am curious how close it is at extended ranges out to 500 yds. I may be able to get away this weekend and try at some longer distances.
 

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I use the Ballistic Calculator at www.handloads.com. I find that if I measure and put in the exact height of scope above the center line of the bore, the altitude and temperature this Ballistics Calculator has been really close.

My 16" Bushmaster is running 2947 FPS with my handload using 55gr. Nosler Ballistic Tips

I have mine zeroed @ 196 yards (= +1.19" at 100 yards).

My Ballistic Chart looks like this:

.223 Remington
16" Bushmaster M4 ORC AR-15
55gr. Nosler Ballistic Tip
25.5grs. Hodgdon H-4895
Military LC Brass / CCI-400 - Rem. 7 1/2 Primers
Ballistic Coefficient = .267 / Sectional Density = .157
Temperature = 70 degrees / Altitude = 1060 Feet
Height of Scope above Centerline of Bore = 2.607"
Range Velocity Energy Trajectory Wind Drift
Muzzle 2947 1061 -2.607 10 M.P.H.
25 yds. 2853 994 -1.24 0.50
50 yds. 2769 936 -0.14 0.71
75 yds. 2687 882 0.68 1.06
100 yds. 2607 830 1.19 1.55
125 yds. 2528 781 1.39 2.19
150 yds. 2450 733 1.24 2.99
175 yds. 2374 688 0.73 3.95
200 yds. 2300 646 -0.17 5.08
225 yds. 2227 606 -1.48 6.39
250 yds. 2155 567 -3.23 7.89
275 yds. 2084 530 -5.44 9.58
300 yds. 2015 496 -8.17 11.47
325 yds. 1947 463 -11.43 13.59
350 yds. 1880 432 -15.25 15.92
375 yds. 1816 403 -19.70 18.50
400 yds. 1753 375 -24.81 21.32
425 yds. 1691 349 -30.63 24.40
450 yds. 1631 325 -37.20 27.76

Sight in + 1.19" at 100 yards = ZERO at 196 yards.

I run a 1.5x4.5x32mm Bushnell Elite 3200 Firefly Riflescope on this Bushmaster with Weaver 1" High Quad Lock Extension Scope Rings on Yankee Hill Machine 1/2" Scope Risers. This puts the centerline of my scope 2.607" above the centerline of the bore and at the perfect height above the comb for me. I have taken over 2 dozen Coyotes with this Bushmaster with this load with the longest shot being 250ish yards.

A buddy uses the same load in a DPMS 16" Sportical AR-15 and has taken Coyotes at least 100 yards farther than I have.

Larry
 

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^^^ good info there :D

i use the Sierra ballistics program works pretty good plus it has a ton of bullet data already in it and you dont have to know the exact info cause of that makes it real nice.
 
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