brentc
Well-Known Member
- Joined
- Apr 3, 2009
- Messages
- 2,635
Some info for those of you that like running heavy loads in the 300 WSM, I did some experimenting today with IMR 7828SSC and the Berger 230 OTM tactical Hybrid. I was intrigued with this combo because of the downrange energy. There simply is not a .308 hunting bullet on the market that can match the energy of this bullet even if flying 100 fps faster. Not even the 210 VLD at 2850.
My rifle is a factory Winchester M70 Extreme Weather, 24" bbl, topped with a Zeiss Conquest 4.5-14x44.
Load information: I used resized and trimmed Norma brass and CCI 200's for the test. I seated the bullets right at the lands, .000 jump which ends up at 3.310" COAL. BTW they still fit in the M70 magazine.
I loaded 18 rounds ranging from 64 - 66 grains of 7828SSC and fired 3 shot groups to determine an OCW. the weather was a little drizzly today, and I ended up losing two chrono readings, but I still feel like I got good data. Here are the results.
Load #1 64.0 grains IMR 7828SSC (Good group .35" all touching)
#1 2650 fps
#2 2624 fps
#3 -------
ES = 26 fps
Ave = 2637 fps (baseline)
Load #2 64.4 grains (Good group .55" in a cluster)
#1 2677 fps
#2 2656 fps
#3 2645 fps
ES = 32 fps
Ave = 2659 fps (+22)
Load #3 64.8 grains (scattered group 1.5")
#1 2682 fps
#2 2666 fps
#3 ------
ES = 16 fps
Ave = 2674 fps (+15)
Load #4 65.2 grains (tightening group .40" group - horizontal all touching)
#1 2688 fps
#2 2704 fps
#3 2672 fps
ES = 32 fps
Ave = 2688 fps (+14)
Load #5 65.6 grains (Tight group .30 with slight vertical)
#1 2721 fps
#2 2710 fps
#3 2682 fps
ES = 39 fps
Ave = 2704 fps (+16)
Load #6 66.0 grains (max load - slightly stiff bolt lift, not a horrible group - group was 2 shots on top of each other and the 3rd was about 1" to the left)
#1 2693 fps
#2 2688 fps
#3 2704 fps
ES = 16 fps
Ave 2695 fps (-9)
You can see the classic pressure curve leading up to the max load. It appears that the accuracy node is 65.4 or 65.5 grains. ES could improve a bit and it might with either of these charges. Overall, I think the test was a success and it opens up a bit more capability with the WSM. This bullet is about as close to wind proof as you'll find for a .30 cal and the down range energy is phenomenal. These are my results in my rifle. Load at your own risk.
My rifle is a factory Winchester M70 Extreme Weather, 24" bbl, topped with a Zeiss Conquest 4.5-14x44.
Load information: I used resized and trimmed Norma brass and CCI 200's for the test. I seated the bullets right at the lands, .000 jump which ends up at 3.310" COAL. BTW they still fit in the M70 magazine.
I loaded 18 rounds ranging from 64 - 66 grains of 7828SSC and fired 3 shot groups to determine an OCW. the weather was a little drizzly today, and I ended up losing two chrono readings, but I still feel like I got good data. Here are the results.
Load #1 64.0 grains IMR 7828SSC (Good group .35" all touching)
#1 2650 fps
#2 2624 fps
#3 -------
ES = 26 fps
Ave = 2637 fps (baseline)
Load #2 64.4 grains (Good group .55" in a cluster)
#1 2677 fps
#2 2656 fps
#3 2645 fps
ES = 32 fps
Ave = 2659 fps (+22)
Load #3 64.8 grains (scattered group 1.5")
#1 2682 fps
#2 2666 fps
#3 ------
ES = 16 fps
Ave = 2674 fps (+15)
Load #4 65.2 grains (tightening group .40" group - horizontal all touching)
#1 2688 fps
#2 2704 fps
#3 2672 fps
ES = 32 fps
Ave = 2688 fps (+14)
Load #5 65.6 grains (Tight group .30 with slight vertical)
#1 2721 fps
#2 2710 fps
#3 2682 fps
ES = 39 fps
Ave = 2704 fps (+16)
Load #6 66.0 grains (max load - slightly stiff bolt lift, not a horrible group - group was 2 shots on top of each other and the 3rd was about 1" to the left)
#1 2693 fps
#2 2688 fps
#3 2704 fps
ES = 16 fps
Ave 2695 fps (-9)
You can see the classic pressure curve leading up to the max load. It appears that the accuracy node is 65.4 or 65.5 grains. ES could improve a bit and it might with either of these charges. Overall, I think the test was a success and it opens up a bit more capability with the WSM. This bullet is about as close to wind proof as you'll find for a .30 cal and the down range energy is phenomenal. These are my results in my rifle. Load at your own risk.
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