08-04-2019, 03:58 PM
centerfire Wrote:A-Tip is not in QL because it is so new, I ran the model using 150SMK. Here is the QL prediction using my actual measured volume in water; I think QL over predicts pressure and velocity in this model. 2100fps to 2200fps looks reasonable but, as always, work up.
Cartridge : 6.5 Grendel (SAAMI)
Bullet : .264, 150, Sierra HPBT MatchK 1755
Useable Case Capaci: 29.113 grain H2O = 1.890 cm³
Cartridge O.A.L. L6: 2.368 inch = 60.15 mm
Barrel Length : 16.0 inch = 406.4 mm
Powder : Hodgdon CFE223 *C
Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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
-10.0 90 26.33 1956 1275 38328 9136 90.8 1.211
-09.0 91 26.62 1980 1305 39598 9266 91.4 1.192
-08.0 92 26.91 2003 1336 40912 9394 92.0 1.173
-07.0 93 27.20 2027 1368 42275 9519 92.5 1.155
-06.0 94 27.50 2050 1400 43688 9642 93.0 1.138
-05.0 95 27.79 2074 1432 45152 9762 93.6 1.120 ! Near Maximum !
-04.0 96 28.08 2097 1465 46672 9880 94.1 1.103 ! Near Maximum !
-03.0 97 28.37 2121 1498 48248 9994 94.5 1.086 ! Near Maximum !
-02.0 98 28.67 2145 1532 49882 10106 95.0 1.069 ! Near Maximum !
-01.0 99 28.96 2169 1566 51580 10215 95.4 1.053 !DANGEROUS LOAD-DO NOT USE!
+00.0 100 29.25 2192 1601 53342 10320 95.9 1.037 !DANGEROUS LOAD-DO NOT USE!
+01.0 101 29.54 2216 1636 55175 10423 96.3 1.021 !DANGEROUS LOAD-DO NOT USE!
+02.0 102 29.84 2240 1672 57077 10521 96.6 1.005 !DANGEROUS LOAD-DO NOT USE!
+03.0 103 30.13 2264 1708 59057 10616 97.0 0.990 !DANGEROUS LOAD-DO NOT USE!
+04.0 104 30.42 2288 1744 61115 10707 97.4 0.975 !DANGEROUS LOAD-DO NOT USE!
+05.0 105 30.71 2312 1781 63257 10794 97.7 0.960 !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 100 29.25 2313 1782 64635 10343 99.6 0.957 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 100 29.25 2037 1382 43480 9740 87.9 1.138
Awesome thanks. I was planning on starting the lever and the cfe223 at 25 grains and working up in my normal fashion of .2 tenth increase, 5 rounds at each charge.
I typically work up like this until I find the velocity spike or dump and then look at my 5 round data under that to find my accuracy node and then adjust the seating depth.
The A-tip from best I could measure is right at 25 thousands less in the case then the smk.
I also was thinking from the 16 inch barrel I would probably end up in the 2150 to 2200 fps range.
Will be fun to try this out. Hopefully before deer season gets here.