.223 Rem &/or 5.56 load data for 77g C Comp & IMR XBR 8208

[greenheadcaller]

Looking for reloading manual and/or program generated load ranges for Nolser 77 gr Custom Comp and IMR XBR 8208 please. I have checked Nosler site and don't see that powder listed in the 5.56 data with this bullet and could use some help. I see the powder charges that some are having luck with, but am looking for min/max data please if any of you have or can generate it, so I can work up with my rifle. Closest thing I have found is Hodgdon manual in that weight, but it's a different bullet....min will get me started but am inquiring to see if anybody has generated something specifically for the Nosler 77 gr with XBR.

(AR platform... Upper developing load for with this bullet carries a 16 inch 5.56 chambered barrel with a 1:7 twist)

Will start low and work up.

Thank you ... and hello - my first post here.

 

[DrMike]

Welcome aboard. Good to see you posting. Hope this helps.

Cartridge : 5.56 mm NATO - 5.56 x 45 mm
Bullet : .224, 77, Nosler CC HPBT 22421
Useable Case Capaci: 23.989 grain H2O = 1.558 cm³
Cartridge O.A.L. L6: 2.260 inch = 57.40 mm
Barrel Length : 16.0 inch = 406.4 mm
Powder : IMR 8208 XBR

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% 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

-20.0 82 18.16 2108 760 32252 8367 87.3 1.136
-18.0 84 18.61 2160 798 34386 8644 88.5 1.106
-16.0 86 19.07 2213 837 36645 8914 89.7 1.077
-14.0 88 19.52 2265 877 39053 9179 90.9 1.045
-12.0 90 19.98 2317 918 41618 9436 92.0 1.014
-10.0 92 20.43 2370 960 44352 9684 93.0 0.984
-08.0 94 20.88 2422 1003 47267 9924 94.0 0.955
-06.0 96 21.34 2475 1047 50377 10153 94.9 0.927
-04.0 99 21.79 2527 1092 53696 10371 95.7 0.900 ! Near Maximum !
-02.0 101 22.25 2580 1138 57242 10577 96.5 0.874 ! Near Maximum !
+00.0 103 22.70 2632 1185 61033 10771 97.2 0.849 ! Near Maximum !
+02.0 105 23.15 2685 1233 65089 10951 97.8 0.825 !DANGEROUS LOAD-DO NOT USE!
+04.0 107 23.61 2737 1281 69433 11116 98.4 0.802 !DANGEROUS LOAD-DO NOT USE!
+06.0 109 24.06 2790 1331 74092 11266 98.8 0.779 !DANGEROUS LOAD-DO NOT USE!
+08.0 111 24.52 2842 1381 79094 11399 99.2 0.757 !DANGEROUS LOAD-DO NOT USE!
+10.0 113 24.97 2894 1432 84473 11516 99.5 0.736 !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 103 22.70 2753 1296 72069 10703 99.9 0.790 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 103 22.70 2474 1047 50322 10356 90.9 0.926

Cartridge : .223 Rem. (SAAMI)
Bullet : .224, 77, Nosler CC HPBT 22421
Useable Case Capaci: 24.298 grain H2O = 1.578 cm³
Cartridge O.A.L. L6: 2.260 inch = 57.40 mm
Barrel Length : 16.0 inch = 406.4 mm
Powder : IMR 8208 XBR

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% 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

-20.0 79 17.60 2033 707 29207 8007 85.4 1.183
-18.0 81 18.04 2083 742 31087 8282 86.7 1.154
-16.0 82 18.48 2133 778 33064 8552 87.9 1.125
-14.0 84 18.92 2183 815 35146 8818 89.1 1.097
-12.0 86 19.36 2234 853 37356 9078 90.3 1.069
-10.0 88 19.80 2284 892 39704 9332 91.4 1.038
-08.0 90 20.24 2334 932 42199 9578 92.4 1.008
-06.0 92 20.68 2385 972 44851 9817 93.4 0.980
-04.0 94 21.12 2435 1014 47670 10047 94.3 0.952 ! Near Maximum !
-02.0 96 21.56 2486 1056 50669 10267 95.1 0.925 ! Near Maximum !
+00.0 98 22.00 2536 1100 53860 10477 95.9 0.900 ! Near Maximum !
+02.0 100 22.44 2587 1144 57259 10676 96.6 0.875 !DANGEROUS LOAD-DO NOT USE!
+04.0 102 22.88 2637 1189 60880 10863 97.3 0.851 !DANGEROUS LOAD-DO NOT USE!
+06.0 104 23.32 2687 1235 64743 11036 97.9 0.827 !DANGEROUS LOAD-DO NOT USE!
+08.0 106 23.76 2738 1281 68867 11197 98.4 0.805 !DANGEROUS LOAD-DO NOT USE!
+10.0 108 24.20 2788 1329 73275 11343 98.8 0.783 !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 98 22.00 2661 1210 63588 10543 99.5 0.836 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 98 22.00 2377 966 44447 9957 88.9 0.982

 

[SJB358]

I'm away from the computer right now but I will gladly run the data when I can.

Welcome to Nosler. Glad to have you here. Sounds like a cool set up. I'm very fond of the 77's out of the 5.56. Turns the platform into a whole nother animal.

 

[greenheadcaller]

Thank you for the data and the responses, this will get me started.

Plan to work XBR next to my pet powder (H322) I use for lighter bullets on these 77's to see if I can find some accuracy with the heavies too.

Have a great afternoon, and thanks again.

 

[Greentimber]

That QL info is a bit surprising. I've done a work up all the way to 24.0gr with no pressure signs at all. Great accuracy and velocity out of my 18" AR.

 

[greenheadcaller]

That QL info is a bit surprising. I've done a work up all the way to 24.0gr with no pressure signs at all. Great accuracy and velocity out of my 18" AR.

What measured velocity did you get with it?

What case did you reload/do you know the internal capacity of the case?

Appears to be pretty darn hot/not recommended according to QL.

I am not chasing velocity, I am just asking to see how close it was to the computer run in the 16 in barrel.

I found good accuracy without going to that extreme...in my rifle.