7mm WSM & IMR 7828

[Mud]

Has anyone every use IMR 7828 powder to load for a 7mm WSM? I'm trying to fix up a load my Dad he wants to use the Berger 168 VLD Hunting bullets in his Browning Bar.

Thanks,

Larry

 

[DrMike]

It is a much slower powder than I prefer to use. However, here is a projection from QL.

Cartridge : 7 mm WSM
Bullet : .284, 168, Berger VLD G7 #28401
Useable Case Capaci: 71.094 grain H2O = 4.616 cm³
Cartridge O.A.L. L6: 2.860 inch = 72.64 mm
Barrel Length : 24.0 inch = 609.6 mm
Powder : IMR 7828 SSC

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 52.64 2399 2148 32194 10495 91.3 1.625
-18.0 80 53.96 2461 2259 34402 10832 92.6 1.582
-16.0 82 55.27 2523 2374 36765 11155 93.8 1.539
-14.0 84 56.59 2585 2492 39294 11463 95.0 1.491
-12.0 86 57.90 2647 2613 42002 11754 96.0 1.444
-10.0 88 59.22 2709 2737 44904 12027 96.9 1.399
-08.0 90 60.54 2771 2864 48016 12279 97.7 1.356
-06.0 92 61.85 2833 2993 51356 12510 98.3 1.314
-04.0 94 63.17 2894 3124 54946 12719 98.9 1.274 ! Near Maximum !
-02.0 96 64.48 2955 3258 58803 12902 99.3 1.235 ! Near Maximum !
+00.0 98 65.80 3016 3394 62955 13060 99.7 1.197 ! Near Maximum !
+02.0 100 67.12 3077 3532 67432 13192 99.9 1.161 !DANGEROUS LOAD-DO NOT USE!
+04.0 102 68.43 3137 3672 72260 13295 100.0 1.126 !DANGEROUS LOAD-DO NOT USE!
+06.0 104 69.75 3197 3813 77441 13376 100.0 1.092 !DANGEROUS LOAD-DO NOT USE!
+08.0 106 71.06 3256 3956 83017 13450 100.0 1.060 !DANGEROUS LOAD-DO NOT USE!
+10.0 108 72.38 3315 4100 89035 13519 100.0 1.028 !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 98 65.80 3146 3693 76356 12541 100.0 1.107 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 98 65.80 2828 2984 50770 12951 95.1 1.315

 

[SJB358]

I know Mike doesn't use it in his 7mm WSM, but I had excellent luck with 7828 in the 270WSM with 150's and have really good shooting loads with RL22 in the 7mm WSM with 160 AB's and the speed is great as well. To me, for what I have seen so far, 7828 has been very close to RL22, so I would think it would be a good one for the heavier bullets in the 7mm WSM, especially once you go above 160 grains. Again, not trying to contradict Mike at all, as he has probably shot 1000's more rounds from the 7mm WSM than I have, but I will likely try some RL25 with the 168 ABLR's when they drop, as the data looks good, and I just gotta try it! :lol:

 

[Mud]

Is there a down side to using a slower burning powder? At the moment all I can find is IMR 7828. I was lucky and found 4 cans of IMR 7828.

Larry

 

[SJB358]

Is there a down side to using a slower burning powder? At the moment all I can find is IMR 7828. I was lucky and found 4 cans of IMR 7828.

Larry

Not that I can tell Larry. As long as it is accurate, whats the loss?

 

[Mud]

Is there a down side to using a slower burning powder? At the moment all I can find is IMR 7828. I was lucky and found 4 cans of IMR 7828.

Larry

Not that I can tell Larry. As long as it is accurate, whats the loss?

Umm.. I don't know when I would find more powder... No has anything in my area.

Larry

 

[caribouhunter]

That's what i use in mine with the 150 gr scirocco.
Best velocity so far @ 3125 fps for 67.5 gr. I got 3230 @ 70 gr. and great accuracy but primers were a bit flat. So i droped down to what i considered normal velocity for the bullet used in that caliber.
I tried H4350 first but couldn't get 3000 fps. Accuracy was the same as my imr7828 load at 2930 fps.

I tried the 168 gr.vld with Rl25 but got only 2700 fps.
I will try them with imr 7828 one day.

My rifle is a savage with a 24" barrel

 

[SJB358]

Umm.. I don't know when I would find more powder... No has anything in my area.

Larry

I think you'll do fine. It would be one of my picks if I were starting right now with 168's.

 

[Oldtrader3]

I use IMR7828 SSC in my 7mm Rem Mag and assume that it would work just as well in the 7WSM. I load 66.0 grains of IMR7828 SSC and the Fed 215 primer for my 7mm Rem mag and get the highest velocity and very good accuracy.

 

[double_d]

My go to load in my 7wsm is with 7828ssc and the 160 deep curl

 

[DrMike]

The bottom line is that we often use powders that aren't "optimum." Powder limitations may force you to use the slower powder. I'm tending toward medium burn powders in my WSMs, but that should not be taken to mean that slow burning powders won't work. I'm getting tighter SDs with the medium burn powders, which nudges me toward their use.