Working up a 68 grain .223 load without breaking the bank

[five.five-six]

I also loaded up some 68 grain Hornday match for my 24" BBL with Varget. 1 round per step.

23.5 grains 2783 fps
23.7 grains 2850 fps
23.9 Crono missed
24.1 grains 2898
24.3 grains 2931
24.5 grains 2934
24.7 grains 2977
24.9 grains 3012
25.1 grains 3023
25.3 grains 3023
25.5 grains 3043
25.7 grains 3065 FPS primer flat; stopped

It's a 1:9 barrel so we'll see if I can get them to consistently stabilize but 25.2 grains looks like a good place to start


Interesting, I’m 79 FPS slower than Randal’s data for 25.2...

[JackEllis]

I had no trouble with 62 grain lead core bullets in a Howa 1500 with a varmint barrel that has a 12" twist IIRC. In fact, I was all set to relegate those bullets to my other .223 with a faster twist but the two rifles shot those bullets equally well.

As for Randall's data, see the caveat at the bottom of his QuickLoad output regarding variations in powder burn rate. Predictive tools are great for developing insights but you also have to be mindful of the assumptions that are baked into them.

[BajaJames83]

Those 68s will work great for you especially with a 1/9 you may not be able to go heavier.

In the Marine Corps we qualify at 500yds with 16" M4s and 62gr ammo

[five.five-six]

I had no trouble with 62 grain lead core bullets in a Howa 1500 with a varmint barrel that has a 12" twist IIRC. In fact, I was all set to relegate those bullets to my other .223 with a faster twist but the two rifles shot those bullets equally well.

As for Randall's data, see the caveat at the bottom of his QuickLoad output regarding variations in powder burn rate. Predictive tools are great for developing insights but you also have to be mindful of the assumptions that are baked into them.

[five.five-six]

Those 68s will work great for you especially with a 1/9 you may not be able to go heavier.

In the Marine Corps we qualify at 500yds with 16" M4s and 62gr ammo

[ar15barrels]

Pressure and velocity generally track together assuming the barrel length is correct.
Temperature is a factor.
If you are 79fps slower, your pressures are lower.
It could be burn rate, chamber volume, temperature or other factors.
Look at what the pressure is on the QL plot at your reduced velocity and that's probably where you are at for pressure.

The more variables you can accurately account for, the closer you can tune quickload to match your actual results.
Only then can you really have a full picture of what's going on.

Here is Qulckload model with 1.4gr more case capacity:

Cartridge          : .223 Rem.
Bullet             : .224, 68, Hornady BTHP M 2278
Useable Case Capaci: 25.814 grain H2O = 1.676 cm³
Cartridge O.A.L. L6: 2.260 inch = 57.40 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Hodgdon VARGET

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.81% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time
 %       %    Grains   fps   ft.lbs    psi    psi      %        ms

-08.1   99    22.70   2734    1129   42001   6455     92.1    1.210
-07.3   99    22.90   2757    1148   43120   6517     92.5    1.196
-06.5  100    23.10   2781    1168   44273   6578     92.9    1.182
-05.7  101    23.30   2805    1188   45457   6638     93.3    1.169
-04.9  102    23.50   2828    1208   46675   6697     93.7    1.155
-04.0  103    23.70   2852    1228   47929   6754     94.1    1.142
-03.2  104    23.90   2876    1249   49220   6811     94.4    1.129
-02.4  105    24.10   2899    1269   50546   6866     94.8    1.116
-01.6  106    24.30   2923    1290   51914   6920     95.1    1.103
-00.8  106    24.50   2947    1311   53320   6973     95.5    1.091  ! Near Maximum !
+00.0  107    24.70   2970    1332   54770   7024     95.8    1.079  ! Near Maximum !
+00.8  108    24.90   2994    1353   56262   7074     96.1    1.066  ! Near Maximum !
+01.6  109    25.10   3018    1375   57801   7122     96.4    1.054  ! Near Maximum !
+02.4  110    25.30   3041    1396   59386   7169     96.7    1.043  ! Near Maximum !
+03.2  111    25.50   3065    1418   61018   7214     96.9    1.031  ! Near Maximum !
+04.0  112    25.70   3088    1440   62695   7258     97.2    1.019  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba    107    24.70   3112    1463   64886   7056     99.4    1.006  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba    107    24.70   2788    1174   45225   6690     88.8    1.172

You can easily get that additional case volume with a long throated barrel.

Here is the same pass at 10 degrees lower powder temperature:

Cartridge          : .223 Rem.
Bullet             : .224, 68, Hornady BTHP M 2278
Useable Case Capaci: 25.814 grain H2O = 1.676 cm³
Cartridge O.A.L. L6: 2.260 inch = 57.40 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Hodgdon VARGET ?, Temperature: 60 °F

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.81% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time
 %       %    Grains   fps   ft.lbs    psi    psi      %        ms

-08.1   99    22.70   2720    1117   41370   6427     91.5    1.218
-07.3   99    22.90   2743    1136   42471   6490     91.9    1.204
-06.5  100    23.10   2767    1156   43602   6552     92.4    1.190
-05.7  101    23.30   2791    1176   44767   6613     92.8    1.176
-04.9  102    23.50   2814    1196   45965   6673     93.2    1.163
-04.0  103    23.70   2838    1216   47198   6732     93.5    1.149
-03.2  104    23.90   2862    1236   48465   6789     93.9    1.136
-02.4  105    24.10   2885    1257   49772   6846     94.3    1.123
-01.6  106    24.30   2909    1278   51110   6901     94.6    1.111
-00.8  106    24.50   2933    1299   52497   6955     95.0    1.098
+00.0  107    24.70   2956    1320   53923   7007     95.3    1.086  ! Near Maximum !
+00.8  108    24.90   2980    1341   55391   7059     95.6    1.073  ! Near Maximum !
+01.6  109    25.10   3004    1362   56902   7109     96.0    1.061  ! Near Maximum !
+02.4  110    25.30   3027    1384   58460   7157     96.3    1.049  ! Near Maximum !
+03.2  111    25.50   3051    1406   60064   7204     96.5    1.037  ! Near Maximum !
+04.0  112    25.70   3075    1428   61722   7249     96.8    1.026  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba    107    24.70   3101    1452   63936   7065     99.2    1.012  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba    107    24.70   2773    1161   44540   6652     88.1    1.180

[3006]

I'm using a chargemaster so the varget is less of a problem.

I'd like to break clays at 300+ and ring steel at 600+

I'm actually already doing that with 55's

Loaded up some a couple weeks ago using Benchmark grouping was not spectacular and the drop at 400 yards was a lot compared to the lighter bullets . Since I might not be using them at known yardage could not see advantage. Next target where I shoot is 600 my 243 and 22.250 are a guarantee at the 400 yard 12x12 plate so I will stick to those for longer ranges.

[Scota4570]

24 gr varget, 68 gr hornady will clean the short line rapids in my 1:8 barrel. I have also shot mid 90s at 600 with the same load.

Pull down 4895 shot about the same. I do use and electronic trickler.

[the86d]

Those 68s will work great for you especially with a 1/9 you may not be able to go heavier.

In the Marine Corps we qualify at 500yds with 16" M4s and 62gr ammo

Wow, I thought the M16A2 was still used for quals, and had no clue...

1) I am curious, do you recall the twist on the M4, I have wondered that?

2) WAIT... WTF did they do with all those A2 uppers/barrels that were in use when I got a DD-214?!?!!?