Quick Load estimate of pressure if possible

[RHux]

I have a load = Lapua 308 Win brass
CCI BR primer
43 gr IMR 8208 XBR powder
Berger 168 Hybrid COAL 2.907 FPS2850

 

[thefitter]

FPS2850

Really?

30" + barrel?

 

[Steve Blair]

Looks reasonable to me. I think your lot is slightly slower than mine.

 

[RHux]

Thank you very much! Yes it is a 30"

 

[RHux]

at 43.2 very minor ejector mark , 43.4 more pronounced mark .

 

[wolley]

This is leaving everything at default values except OAL. 8208XBR can be quite variable from one lot to the next.
Cartridge : .308 Win. (SAAMI)
Bullet : .308, 168, Berger Hybrid G7 #30425
Useable Case Capaci: 49.692 grain H2O = 3.226 cm³
Cartridge O.A.L. L6: 2.907 inch = 73.84 mm
Barrel Length : 30.0 inch = 762.0 mm
Powder : IMR 8208 XBR

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.721% 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

-17.2 78 35.60 2397 2144 34263 4871 97.4 1.685
-15.5 79 36.34 2439 2220 36050 4960 97.9 1.651
-13.8 81 37.08 2481 2297 37924 5045 98.3 1.618
-12.0 83 37.82 2523 2374 39889 5126 98.7 1.581
-10.3 84 38.56 2564 2453 41950 5201 99.1 1.546
-08.6 86 39.30 2605 2531 44111 5272 99.4 1.512
-06.9 87 40.04 2646 2611 46377 5337 99.6 1.480
-05.2 89 40.78 2686 2691 48755 5397 99.8 1.448
-03.4 91 41.52 2726 2771 51250 5452 99.9 1.418
-01.7 92 42.26 2765 2852 53868 5501 100.0 1.389 ! Near Maximum !
+00.0 94 43.00 2804 2933 56616 5544 100.0 1.360 ! Near Maximum !
+01.7 95 43.74 2843 3015 59503 5585 100.0 1.332 ! Near Maximum !
+03.4 97 44.48 2881 3097 62536 5624 100.0 1.306 !DANGEROUS LOAD-DO NOT USE!
+05.2 99 45.22 2919 3179 65724 5663 100.0 1.280 !DANGEROUS LOAD-DO NOT USE!
+06.9 100 45.96 2957 3262 69077 5701 100.0 1.254 !DANGEROUS LOAD-DO NOT USE!
+08.6 102 46.70 2994 3345 72605 5737 100.0 1.230 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 5% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 5% relative to nominal value:
+Ba 94 43.00 2849 3029 61427 5419 100.0 1.318 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba 94 43.00 2748 2817 51844 5651 99.5 1.408