WC857 Powder for 7mm Rem Mag ... Yup, I'm *that guy* ?
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Shot a simple single shot ladder test of WC857 in my 7mm Rem Mag today. Bullets were the 180 Berger target hybrids seated 20 thou off the lands. Started at 63 grains and worked up to 70. At 70 grains, ended up at 2774 fps out of my 24" barrel. Clearly WC857 is faster than WC860. Brass looks good. Thinking I can carefully work up to an additional 1-2 grains of the WC857 and call it done.
I also shot some RamShot Magnum for the first time. 68 grains of that stuff ended up at 2910 fps. May go .5 gr more to get a solid mid-2900 result. Looking forward to now doing some real shooting with my new toy, rather than dicking around with military surplus powders!
So yup, now "I'm that guy" too.
I also shot some RamShot Magnum for the first time. 68 grains of that stuff ended up at 2910 fps. May go .5 gr more to get a solid mid-2900 result. Looking forward to now doing some real shooting with my new toy, rather than dicking around with military surplus powders!
So yup, now "I'm that guy" too.
Did a bit more velocity testing with WC857 in 7mm Rem Mag. Still a bit more top end beyond this as brass and primers look great. Virtually no bolt lift:
WC857 70.5 2785/2744/2764 SD=15
WC857 71.0 2829/2785/2802 SD=18
WC857 71.5 2849/2808/2832 SD=17
Moving on to try 72 & 72.5 grains next. Will include a full 5=shot comparison of RamShot Magnum at 69 and 69.5 grains. RamShot seems consistently slightly faster.
WC857 70.5 2785/2744/2764 SD=15
WC857 71.0 2829/2785/2802 SD=18
WC857 71.5 2849/2808/2832 SD=17
Moving on to try 72 & 72.5 grains next. Will include a full 5=shot comparison of RamShot Magnum at 69 and 69.5 grains. RamShot seems consistently slightly faster.
WC857 continues to impress in the velocity department. Tested 72.0 & 72.5 grains with the Berger 180's. 72.5 ended up as follows:
Mission accomplished to safely break the 2900 fps barrier. Tested RamShot Magnum to 69.5 grains and got the following confirming again its slightly faster:
Brass on both still good, but going to call it done in terms of velocity testing. No point in pushing this any further out of a 24" hunting profile barrel.
Mission accomplished to safely break the 2900 fps barrier. Tested RamShot Magnum to 69.5 grains and got the following confirming again its slightly faster:
Brass on both still good, but going to call it done in terms of velocity testing. No point in pushing this any further out of a 24" hunting profile barrel.
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The following graph was my experience with WC860 in a .338 Edge (.338/.300 RUM) with 300gr projectiles in a 25" barrel. Someone locally refers to it as "energetic coal" since with a totally full case of 106.5gr it's still low pressure.
Red X is Retumbo speed
Blue X is WC860 speed
Red circles are Quickload-predicted speed with US869
Green line is Quickload pressure (right hand scale) with US869.
Red X is Retumbo speed
Blue X is WC860 speed
Red circles are Quickload-predicted speed with US869
Green line is Quickload pressure (right hand scale) with US869.
I don't have Retumbo or any of the magic fairy dust RL-26, but I do have a pound of RL-33. Anyone think its worth a try with the 180/190 gr Bergers out of a 7mm mag with a 24" barrel? Tried a couple of the 190's with the WC857 and got 2736 from 70 grains. Pretty sure I can safely get 2800+ out of this combo.
I still have 2 gallons of H857 that my family has been shooting in our Sako 7Mags since the 70s. I was told it was an expiramental 50bmg tracer powder that was discontinued. My grandfather bought 30 gallons of it. Sounds identical to the wc857. Our go to load for 140gr bullets has been 74gr. It's lights out. Well below moa in both of my Finnbears
Ordered a new 27" 7mm mag 1-8 twist barrel last week. Should up the velocity well over 3000 fps no problem with the 180's. Just have to wait 12-14 weeks to get it! Longer throat as well. Should be interesting.
I wouldn't hesitate to go with this powder again. I have probably 15# of RL26 and, obviously primers are a thing now. I have enough magnum primers to burn a couple barrels 
So finally got my new 27" 7mm mag 1-8 twist barrel in last week. Initial chrono test done today after about 50 round through the new tube. Only got a roughly 40 fps increase. Thought it would have been a bit more with 3 extra inches, but is what it is. Maybe I'll pick up a bit more speed after more use. Did get a better SD value. Once I get 150+ rounds through it I'll test again.
Berger 180 LRHT, avg 2949fps, SD=4, 72.5gr WC857
Berger 180 LRHT, avg 2949fps, SD=4, 72.5gr WC857
Thats no slouch with 180's and in a new tube, i would bet it will speed up a little once you get a few more rounds down the bore.
The throat on the new tube is longer by design. An additional 92 thou to hit the lands with this bullet in the new barrel. Hoping to safely add an additional .5 gr of powder with the additional real estate by seating a tad longer.
Did some more experimentation today with this powder in my new 7mm Mag. Round count now totals 121. That same load (Berger 180 LRHT, avg 2949fps, SD=4, 72.5gr WC857) now produces about 35fps more:
I also upped my load by .3 grains to 72.8 . While that definitely put me over the 3k mark, rounds became too difficult to extract. In my rifle with new PPU brass 72.5 +/- 1 grain is about it.
The real surprise was finally testing the Berger 190 LRTH. Accuracy was VERY good out of my 1-8 twist and already getting well over 2900 fps with no bolt lift problems at 71.3gr of WC857. Can easily go another .2 grains, maybe more.
One more outing should wrap up the testing with this powder.
I also upped my load by .3 grains to 72.8 . While that definitely put me over the 3k mark, rounds became too difficult to extract. In my rifle with new PPU brass 72.5 +/- 1 grain is about it.
The real surprise was finally testing the Berger 190 LRTH. Accuracy was VERY good out of my 1-8 twist and already getting well over 2900 fps with no bolt lift problems at 71.3gr of WC857. Can easily go another .2 grains, maybe more.
One more outing should wrap up the testing with this powder.
The hard part with ball powders is the SD doesn't seem to get down there like extruded stick stuff. But, it's can be very accurate if worked with. My loads were solid 3/4 MOA in most conditions. I found this powder to be kinda sensitive to temps... like 1.75-2fps per degree.
Pulled the Berger 180's I decided were too hot. Looked at the compression of the powder vs. accuracy results. Making the correlation that too much compression with WC857 is resulting in less than optimal accuracy. Not 100% sure yet, but results trending that way. WC860 may be better for compressed loads in bullet weight class. I'm no expert on this topic with military surplus powders. Just an observation at this stage of my testing.
This was a great read b/c I'm lusting after the idea of pushing a 190 ATip in the 2900+ range with ball powder in some 7mm caliber. I'm stuck on not trickling with Staball has made me lazy and I ain't changin. Any new developments here since last May? Thanks
I throw stick powders in my 300WM, and still get SDs below 15. Two or four tenths of grain in a much smaller percentage of the total charge weight in the big cases.
I think the last of it was available when I puchased a bunch through GI Brass (Jeff Bartlett) about two years ago. Long since gone and not comming back far as I'm aware. Too bad. I use it all the time for heavys in my custom 7mm Rem Mag.
Doesn't indicate stock status. Could be in stock! Says $120/8#. Used to be $60-80/8#... still $15/# of 857
