45-70 load wanted using RL7

[RogueRiver]

Okay got my dies so I'm ready to load some Trapdoor level loads using RL7. I have 2lbs on hand so this is the powder I want to try. I will be using 405 grn rem bulk bullets. The gun is a contender w/ 23" barrel.

 

[Wally]

RR,

I happen to have been rehashing an article in Handloader 248 (Aug-Sept 2007), that has a very good article on loading for the 45-70 by Brian Pearce. IMHO, he is probably one of the best contemporary authorities on this cartridge. He lists some loads using the 400 Speer flat softpoint and RL-7, which he says do not exceed 21,000 CUP. This is the maximum pressure he recommends for a Trapdoor Springfield. His starting load is 41.0 grs, and he goes up to 45.0 grs.

Hope this helps.

Steve

 

[FOTIS]

Cartridge : .45-70 Govt. SAAMI
Bullet : .458, 405, Remington SP
Cartridge O.A.L. L6: 2.550 inch or 64.77 mm
Barrel Length : 23.0 inch or 584.2 mm
Powder : Alliant Reloder- 7

Predicted data by increasing and decreasing the given charge,
incremented in steps of 3.0% 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

-30.0 62 30.80 1368 1683 17067 2385 87.7 2.138
-27.0 64 32.12 1419 1812 18506 2511 89.4 2.059
-24.0 67 33.44 1470 1944 20070 2635 91.0 1.985
-21.0 70 34.76 1521 2079 21770 2754 92.4 1.915
-18.0 72 36.08 1571 2218 23615 2869 93.7 1.848
-15.0 75 37.40 1620 2361 25613 2980 94.9 1.785
-12.0 77 38.72 1669 2506 27775 3084 96.0 1.725
-09.0 80 40.04 1718 2654 30113 3182 97.0 1.668
-06.0 83 41.36 1766 2805 32640 3274 97.8 1.614
-03.0 85 42.68 1814 2958 35371 3359 98.4 1.562
+00.0 88 44.00 1861 3113 38324 3436 99.0 1.510 ! Near Maximum !
+03.0 91 45.32 1907 3271 41516 3505 99.4 1.460 ! Near Maximum !
+06.0 93 46.64 1953 3430 44971 3566 99.7 1.412 !DANGEROUS LOAD-DO NOT USE!
+09.0 96 47.96 1998 3590 48711 3619 99.9 1.367 !DANGEROUS LOAD-DO NOT USE!
+12.0 99 49.28 2043 3752 52766 3662 100.0 1.323 !DANGEROUS LOAD-DO NOT USE!
+15.0 101 50.60 2087 3915 57165 3700 100.0 1.282 !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 88 44.00 1932 3357 45314 3305 100.0 1.416 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 88 44.00 1761 2787 31615 3412 94.3 1.625

 

[RogueRiver]

thanks wally I will have to look that article up. I am a fan of Handloader, Rifle and hunter. They have writers that know what they are talking about and live in the west.

Pop if I'm reading your calculations right I should stick to the first three lines of data for trapdoor level loads.

-30.0 62 30.80 1368 1683 17067 2385 87.7 2.138
-27.0 64 32.12 1419 1812 18506 2511 89.4 2.059
-24.0 67 33.44 1470 1944 20070 2635 91.0 1.985
-21.0 70 34.76 1521 2079 21770 2754 92.4 1.915

 

[FOTIS]

Correct,

I put in 44K psi as a max for this prediction.

 

[FOTIS]

Cartridge : .45-70 Govt. SAAMI
Bullet : .458, 405, Remington SP
Cartridge O.A.L. L6: 2.550 inch or 64.77 mm
Barrel Length : 23.0 inch or 584.2 mm
Powder : Alliant Reloder- 7

Predicted data by increasing and decreasing the given charge,
incremented in steps of 3.0% 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

-30.0 53 26.60 1203 1302 13062 1969 81.5 2.426
-27.0 55 27.74 1248 1401 14070 2083 83.3 2.342
-24.0 58 28.88 1293 1504 15136 2196 85.0 2.262
-21.0 60 30.02 1338 1609 16261 2309 86.6 2.187
-18.0 62 31.16 1382 1718 17449 2420 88.2 2.116
-15.0 65 32.30 1426 1829 18711 2528 89.6 2.049
-12.0 67 33.44 1470 1944 20070 2635 91.0 1.985
-09.0 69 34.58 1514 2061 21530 2738 92.2 1.924
-06.0 71 35.72 1557 2180 23097 2838 93.4 1.866
-03.0 74 36.86 1600 2302 24776 2935 94.5 1.810 ! Near Maximum !
+00.0 76 38.00 1643 2426 26575 3028 95.4 1.757 ! Near Maximum !
+03.0 78 39.14 1685 2553 28499 3116 96.3 1.707 !DANGEROUS LOAD-DO NOT USE!
+06.0 81 40.28 1727 2681 30558 3200 97.1 1.658 !DANGEROUS LOAD-DO NOT USE!
+09.0 83 41.42 1768 2812 32759 3278 97.8 1.611 !DANGEROUS LOAD-DO NOT USE!
+12.0 85 42.56 1809 2944 35114 3351 98.4 1.566 !DANGEROUS LOAD-DO NOT USE!
+15.0 87 43.70 1850 3078 37632 3419 98.9 1.522 !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 76 38.00 1723 2671 31308 3033 99.2 1.644 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 76 38.00 1540 2132 22131 2892 88.4 1.888

 

[kraky]

I read somewhere..perhaps even the quickload manual...that ql has a very hard time predicting large straight wall cartridges.
AND THE ANSWER IS...IT DOES. In my marlin it predicted 47 grains of re7 under a rem 300 hp would do 1985 fps...it did 1700. It predicted 54 grains of h322 would do 2059....it did 1900.
This gun is dead on the nuts with what sierra's reloading manual predicts for speed with their data......and I would recomend that is a far better source for your data than quick load. Not trying to be a smart aleck but I've got some experience with the 45-70 and with ql......and I usually brag the heck out of ql.....but not for this cartridge.