7 Rem Mag, question?

[Guest]

Hello all,
Anyone have any idea on velocity of 65.5 RL22, 160 AccuBond, CCI 250 mag primer, new Hornady cases (if that matters). 24" barrel.
I'd post targets but the darn photo link won't work for me right now. (that I can fix I think)
Reason I need an idea on speed is I shot the darn chrono screens. No spares(ordered now)
Scope view from the rest was good, boom, goodbye screens. Anybody else ever do a trick like that?
Man, I looked around to make sure no one saw me. :lol:
Geez.
Dewey

 

[DrMike]

QL projects 2979.

Cartridge : 7 mm Rem. Mag.(SAAMI)
Bullet : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 72.296 grain H2O = 4.694 cm³
Cartridge O.A.L. L6: 3.290 inch = 83.57 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : Alliant Reloder-22

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 78 52.40 2379 2011 30123 10449 91.1 1.634
-18.0 80 53.71 2439 2114 32158 10788 92.4 1.594
-16.0 82 55.02 2500 2220 34334 11116 93.6 1.555
-14.0 84 56.33 2560 2328 36658 11430 94.7 1.517
-12.0 86 57.64 2620 2439 39143 11730 95.7 1.469
-10.0 88 58.95 2680 2553 41793 12015 96.6 1.425
-08.0 89 60.26 2741 2669 44592 12282 97.4 1.381
-06.0 91 61.57 2801 2787 47562 12531 98.1 1.340
-04.0 93 62.88 2860 2907 50726 12759 98.7 1.300
-02.0 95 64.19 2920 3029 54098 12967 99.2 1.262 ! Near Maximum !
+00.0 97 65.50 2979 3154 57692 13153 99.5 1.225 ! Near Maximum !
+02.0 99 66.81 3038 3279 61527 13315 99.8 1.189 !DANGEROUS LOAD-DO NOT USE!
+04.0 101 68.12 3097 3407 65620 13453 100.0 1.155 !DANGEROUS LOAD-DO NOT USE!
+06.0 103 69.43 3155 3536 69993 13565 100.0 1.121 !DANGEROUS LOAD-DO NOT USE!
+08.0 105 70.74 3212 3666 74669 13664 100.0 1.089 !DANGEROUS LOAD-DO NOT USE!
+10.0 107 72.05 3269 3798 79673 13760 100.0 1.058 !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 97 65.50 3112 3442 69501 12713 100.0 1.131 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 97 65.50 2790 2766 46179 12939 94.7 1.349

Shoot long enough and you'll eventually bust a screen or two. I've lost a screen even to walnut media stuck in the case on one occasion. It made a very tiny, but distinct hole in the front. Since then, I've put a plexiglass shield over the from electronics. I've shot at least six or seven sky-screens. I've even managed to take out an Oehler, the bullet just nicking the top of the screen (It is not pretty to see what a 250 grain AccuBond will do to one of these screens.). I can testify that generally these chronographs will take a lickin' and keep on tickin'. All these companies sell parts to get you back up and running pretty quickly.

 

[Guest]

Thank you, sir. Both for the numbers and kind words.
Good thing I have my own little range and didn't have to worry too much about spectators. :roll:
D

 

[SJB358]

Dewey, that load is usually about 2950-3000 out of most 7mm Mags. It is about as good as a known good load as I can think of.

Sorry about the chrono, I'm still waiting to kill my first one.

 

[Guy Miner]

Dewey, that load is usually about 2950-3000 out of most 7mm Mags. It is about as good as a known good load as I can think of.

Sorry about the chrono, I'm still waiting to kill my first one.

Yes indeed. About 65 grains of RL-22, and a good 160, the 7mm Rem mag does real well. Sierra turned me on to that load a long time ago.

 

[Guest]

Thanks guys.
I ran through the whole ladder deal and that was what it liked.
It also really liked the Accubonds with a little jump to the lands. (Around 10)
Felt good and found the length it liked. Just getting set to check it and shot the darn chrono.
Weird day. Excellent results with 3 rifles but killed the chrono. :grin:
Got the 257 bee exactly where I wanted it, the 6 mm, and the 7.
Guess I'll settle for that.
Dewey