Home Forums Reloading Big Game Rifles Best Powders to Burn in a 7MM WSM?

What Powder should I try with a 7MM WSM with a 24" BBl, 1 in 9 twist using a 160 Pill? Got one coming and don't have a clue.

Thanks,

Dee

I just did a bunch of shooting with my 7 RM (case capacity pretty close to WSM) with 160 Nosler's. Based on my experience with the 7mm RM, I'd try H1000, Retumbo, Magnum, I 7828, MagPro, RE 22. In my 7 RM, I'm re-shooting IMR 7828 and MagPro as it turned in good velocity and good groups (~ 1"). I'm also going to run a few RE 25 as well. You should be able to get on the north side of 3000 with 160 in a 24" WSM. I'm getting 3050 - 3100 with my 26" 7mm RM and 160 Nosler's.

I find that the bigger 7mm cases can hold a heck of alot more powder than some data suggests. I can safely run 75-77 grains of powder in the 7 RM. I see lots of load data shooting ~60 - 65 grains of powder. That tells me that the powder being used is too fast. I also like my case filled - and don't mind compressing powder a bit. I usually get real low velocity ranges when I use a full case.

Personally, I'd be all over 7828.

That's what I ran when I was shooting a 7 WSM.

Dober

You can use the slightly faster powders if you are happy with a little less velocity. 2950 fps or so is about all anyone should need with a 160 gr 7mm pill unless something is way way out there that needs killing. RL-17 or any of the 4350s can get you around 2950 fps - I tried Magpro back a while ago and yeah it could go over 3000, but with about 10-12 grains more powder, there was noticably more recoil. bwinters is probably right on the vel spread though, I'd just rather not deal with the consequences on the other end of the gun.

We have had consistantly good results using AA4350 in my son's Ruger 7mm SAUM. I know it is not the cartridge you are interested in, but it is very similar.

Thanks for the advise guys. Much appreciated.

Dee

My 7 WSM would put the first two in the same hole with RL 19.

blu - you're spot on. The tradeoff of getting that extra 50-75 ft/sec is increased recoil. The 4350 range of powders gets you most of the 7 mag performance with a good return on the recoil investment. I've shot lots of IMR 4350 through 7 mags and it is very recoil friendly - the slower powders not so much.

For me and my surgically repaired shoulder - I can take the 7 mag recoil using slower powders. Sold the 300/338 mags because it was more recoil than I cared to endure. The 160's in a 7 RM in an 8lb rifle is not bad at all - not much more than an 06. Plus, the BC for 160 boolits is almost identical to the 30 cal 180's. The 7's are more user friendly and provide almost the same ballistics.

And were would the third one go...

Dober

I don't rememeber a lot about what I burned in the 7WSM,but pretty sure it was RL 22.I am working a lot lately with RL25 in a couple of 7mm mags, a 7mm Rem Mag,and the 7mmDakota,and am getting very good velocities in both with 160 gr bullets. I see no reason it should not do very well in the WSM,especially with heavy bullets of 160 gr or so.

I've had promising results with the MagPro and 160 gr Accubonds.

BobinNH what speeds are you getting with the 7mm rem mag and the 7mm Dakota with the 160's and RL-25?
Thanks
Elmer

Elmer: In the 7 RM ( a custom with 24" Douglas, I think) on a M70 action, I'm using 68 RL25,Fe 215 primer, with the 160 Partition for about 3080.It shoots very well with that.Alliant data shows 70 grains with some bullets,but this rifle gives the velocity I've come to expect from a 160,so have not pushed it further.

The Dakota has a 24" Krieger 9 twist and gives a bit over 3100 with the 160 Sierra and 160 Bitterroot.Load is 74 gr RL 25,Fed 215. I could likely bring this load easily to around 3200 but it shoots so well out to 500 Yards that I am not going to mess with it.

7828 seems to be the go to powder in the big 7's.Burn alot in 7 Rem and the STW.Always accurate and fast..

Mike: Yes, I've used it myself,and it is a VG powder. This Dakota was a bit fussy; it shot everything from 120 TTSX(3550),140 AB(3375),and 150 S'II's(3225) very well with RL22.

For some reason, it did not like RL 22,7828,H4831,etc, with the 160's.Soon as I went to RL25,the 160's started to perc like I knew they should...go figure

Syncerus: I don't know a lot about Magpro, but it's supposed to be good....hard to keep up with all the components today...

Here is some WSM loading data.

http://web.archive.org/web/20050313194917/shortmags.org/shortmags/downloads.htm

I load RL 22 in a 7mm WSM with bullets from 140 to 168 grs.

Check here on posts by Mule Deer. He (JB) has suggested some new powders.

syn - I just tried MagPro in my 7 RM with 160 Partitions. It shot right at an inch and 3050 in my 26" barrel. I'm re-shooting them again - this time with 5 shot groups to see if it repeats.

Third opened to 3/4". I gave that rifle, Ruger All Weather with a 3-9 Burris Short Mag, to my son in law when he married into the family. He loves it.

The reason I said "promising results" is that I was testing a brand new rifle and was using a hunting (3x9) scope. I can't really shoot for load testing accuracy with only 9x (my eyes have some issues); when I do serious testing, I use a 36x scope.

Even with the hunting scope, I was shooting about 1.5" groups, which is a pretty good start. My load was 1 or 2 grains under max, per two different manuals.

For a thin-barreled autoloader, I would rate my results as quite good.

I had tried a moderate load of Varget and 160 gr Speer Grand Slams, but the loads weren't hot enough to cycle completely; so I went to a hotter load of a slower powder to improve the functioning.