RL17 6BR

[Webster]

I have a 6BR 14 twist 65-68 gr bullets. I bought a lb. of RL17 because it was the only powder in the store. From what I read it's only used with bigger cartridges. The burn rate is similar to 4831 & 4350 which are not used in a 6BR. Possibly 6BR with 105 gr bullets. Did I waste my money? Does anyone have load data for RL17 6BR 68 gr bullets?

 

[Laurie]

I reckon you'll struggle to find anybody who's tried this combination!

Anyway, I ran it through the QuickLOAD program and here's what it says for a compressed load under a 68gn Berger in a 26-inch barrel.

Cartridge : 6 mm B.R. Rem
Bullet : .243, 68, Berger M
Useable Case Capaci: 35.641 grain H2O = 2.314 cm³
Cartridge O.A.L. L6: 2.200 inch = 55.88 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Alliant Reloder-17

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.261% 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

-02.6 103 35.55 3373 1718 50313 7788 94.2 1.067 ! Near Maximum !
-02.4 103 35.64 3383 1728 50778 7809 94.4 1.063 ! Near Maximum !
-02.1 104 35.74 3393 1738 51250 7830 94.5 1.058 ! Near Maximum !
-01.8 104 35.83 3403 1748 51725 7850 94.6 1.054 ! Near Maximum !
-01.6 104 35.93 3412 1758 52206 7871 94.8 1.050 ! Near Maximum !
-01.3 105 36.02 3422 1768 52687 7891 94.9 1.046 ! Near Maximum !
-01.0 105 36.12 3432 1779 53183 7911 95.1 1.041 ! Near Maximum !
-00.8 105 36.21 3442 1789 53679 7931 95.2 1.037 ! Near Maximum !
-00.5 105 36.31 3452 1799 54180 7950 95.3 1.033 ! Near Maximum !
-00.3 106 36.40 3462 1809 54688 7970 95.4 1.029 ! Near Maximum !
+00.0 106 36.50 3472 1820 55201 7989 95.6 1.025 ! Near Maximum !
+00.3 106 36.60 3482 1830 55719 8007 95.7 1.020 ! Near Maximum !
+00.5 106 36.69 3492 1841 56242 8026 95.8 1.016 ! Near Maximum !
+00.8 107 36.79 3501 1851 56771 8044 96.0 1.012 ! Near Maximum !
+01.0 107 36.88 3511 1861 57307 8062 96.1 1.008 ! Near Maximum !
+01.3 107 36.98 3521 1872 57849 8080 96.2 1.004 ! Near Maximum !

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 106 36.50 3667 2030 65717 8012 99.6 0.949 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 106 36.50 3221 1567 45672 7487 87.0 1.121


It's not as 'silly' as I imagined it'd be. A case stuffed really full does get you to the mid 50,000s psi. How it'll perform in group size, well who knows! The charge burn ratio in the 94-96% band is lower than I'd like, but this doesn't necessarily mean the load won't perform - just that you'll have a fair bit of crud to clean out after a shoot.

I'd start at ~36gn, use a funnel with a long drop tube to get the powder packed in and work up from there.

The usual caveats about this being a computer model and not tested data apply - I hope this helps.