Hi guys, I'm loading up some Scirrocco 130 grainers to see how they behave in my 6.5 creedmoor. I can't find any data on that combination with H4350 except for a guy in an article running with 43 grains.
I'd really appreciate it if someone can please have a quick look at what quickload says about it.
Barrel is 23" 1 in 8 twist. Saami chamber. Hornady brass. COAL 2.8" and is about 4k off the lands.
Added 7200 psi to start pressure, recommended if seating to touch the lands.
Cartridge : 6.5 Creedmoor Hornady
Bullet : .264, 130, Swift Scirocco
Useable Case Capaci: 47.251 grain H2O = 3.068 cm�
Cartridge O.A.L. L6: 2.800 inch = 71.12 mm
Barrel Length : 23.0 inch = 584.2 mm
Powder : Hodgdon H4350
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 81 34.40 2328 1564 39657 7919 92.1 1.356
-18.0 83 35.26 2379 1633 41686 8140 93.0 1.327
-16.0 85 36.12 2430 1704 43822 8355 93.8 1.298
-14.0 87 36.98 2481 1776 46070 8565 94.6 1.271
-12.0 89 37.84 2531 1850 48436 8769 95.3 1.244
-10.0 91 38.70 2582 1925 50929 8966 96.0 1.218
-08.0 93 39.56 2633 2002 53555 9155 96.7 1.192
-06.0 95 40.42 2684 2080 56339 9336 97.3 1.167 ! Near Maximum !
-04.0 97 41.28 2735 2159 59304 9508 97.8 1.142 ! Near Maximum !
-02.0 99 42.14 2786 2240 62460 9670 98.3 1.118 !DANGEROUS LOAD-DO NOT USE!
+00.0 101 43.00 2836 2322 65823 9822 98.7 1.094 !DANGEROUS LOAD-DO NOT USE!
+02.0 103 43.86 2887 2406 69406 9963 99.1 1.071 !DANGEROUS LOAD-DO NOT USE!
+04.0 105 44.72 2937 2490 73228 10092 99.4 1.049 !DANGEROUS LOAD-DO NOT USE!
+06.0 107 45.58 2988 2576 77306 10209 99.6 1.026 !DANGEROUS LOAD-DO NOT USE!
+08.0 109 46.44 3038 2664 81662 10313 99.8 1.004 !DANGEROUS LOAD-DO NOT USE!
+10.0 111 47.30 3088 2752 86318 10403 99.9 0.983 !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 101 43.00 2946 2505 75331 9596 100.0 1.042 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 101 43.00 2691 2090 56376 9623 93.9 1.159 ! Near Maximum !
The second set of results is what the program spits out when 7200 psi is added to the Start Pressure, which is what is suggested if you seat up against the lands.
You've stated, if I understand correctly, you're seating 0.004" off the lands. Sounds perfectly reasonable and typical...
I've posted both so that you can see what seating to touch the lands will do to pressure.
What I question is this: just how far off the lands do you have to be to get normal start pressures? Is it 0.00001" or is it 0.0005" or is it 0.005"? I honestly do not know and I don't know anyone who's ever given a good, reliable, and authoritative answer.
I'd say you're most likely operating somewhere between these two extremes.
Thanks very much RiverRider