Chrony results today

[Henry45]

Hey folks, went out to the range today and finally got to spend a day with the chrony, and the AR and a pistol. Would like your opinions on the results of my loads for the AR. These are the total average velocities for the 10 shot groups.

S&W MP15 Sport, 5.56, 16"bbl

All with Wolf 223 primers, (which worked excellently for the price you can get them at right now).

All 55g military type bullets w/cannalure

2.20 OAL

H335 - 24.5 g = 2712 Highest 2787/Lowest 2656
H335 - 25g = 2769 Highest 2836/Lowest 2711
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2.215 OAL

WC 844 - 25g = 2745 Highest 2778/lowest 2720
WC 844 - 26g = 2822 Highest 2845/Lowest 2793
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Also shot some Federal 223 rounds and their total came out to 2845 average.


Didn't shoot any LC this time, but have seen them running around 3000-3100 fps.

A little light on the loads, i think. Go a little heavier maybe?

No signs of overpressure, a couple of ejections were light on the lightest loads.

Your opinions are greatly appreciated.

 

[JimKirk]

I chronographed a few loads a little while back ... out of a DPMS Sweet-Sixteen.

Federal (Walmart 100 pk) 55 gr FMJ ... 2893 fps

55 gr Sierra SP ... 23.4 grs RL10X ... 2860 fps

60 gr Nosler Partation ... 25 gr RL15 ... 2654 fps ... I got work on this load some more...

Different guns ... but we are not too far between...

 

[CGT80]

Ruger Mini 14 Target Model
22" barrel
1:9 twist

mixed brass
55 FMJBT Hornady
CCI SRM primer
H-335 powder
No Crimp

String 19 Mini 14 55 FMJBT 23.2 H-335
1) 3041 91.5
2) 2928 -21.5
3) 2912 -37.5
4) 2917 -32.5

High: 3041
Low: 2912
E.S.: 129
Ave.: 2949.5
S.D.: 61.4
95%: 112.8

String 20 Mini 14 55 FMJBT 24.0 H-335
1) 3106 94.2
2) 3036 24.2
3) 2939 -72.8
4) 2921 -90.8
5) 3057 45.2

High: 3106
Low: 2921
E.S.: 185
Ave.: 3011.8
S.D.: 79.1
95%: 109.8


I use the 23.2 grain load as it gave me the tightest groups. It also has lower SD numbers. I should probably run 10-20 rounds for more accurate chrono numbers next time. After picking that load, I adjusted the harmonic dampener on the barrel to tighten up the group. It has been about 4 years since I shot groups with it. I am not real experienced with shooting groups. I did consistently hit a 1" target (piece of PVC pipe laying on ground) at around the 100 yard line. More experienced shooters claim to have shot sub 1" groups at 100 yards with the same model gun. I also have not tried a heavier bullet to see it it works better in the 1:9 twist.

It is interesting that the Target model is only chambered for 223 and all the other minis are chambered 5.56. I see that my ammo is running faster with less powder. Edit: I am also running a longer barrel, so that may be the reason for more speed.

My brother gets to pickup his Stag 3G AR, next week. It will be interesting to see how that does and what bullet it likes.

 

[Walkalong]

My plinker loads with 55 Gr FMJ in a 16" AR run from 2900 to 3000 FPS, depending on the powder. No need to hot rod things.

 

[chris in va]

I can't wait to get a ProChrono to test my Sport loads.

 

[medalguy]

More importantly, how was the accuracy? As long as you are getting accurate results, there's no need to go with a heavier load. Use the load that gives you the best accuracy, not to exceed the maximum load. That's my rule.