W867 Powder for 338 Lapua Magnum (Help Please) **RESOLVED**

[Flea21]

I seem to have several 8lb jugs W867 from when I loaded for 50 BMG. I have since left that game and focused my big bore magnums toward 338 Lapua Magnum. That being said, I want to use this for my 338s and just curious if anyone has any knowledge or history working with this powder for this caliber.

If so, I would appreciate it if you could please share what you’ve learned so that I can have some point of reference… Thank You.

 

[ChrisGarrett]

Long range hunter

Chris

 

[Flea21]

Long range hunter

Chris

Thanks Chris… I’ve been searching high and low and found that thread through google as well. I was wondering if someone here maybe able to shed more light on this for me.

 

[sirhrmechanic]

W867 is one of the powders I use for .50 BMG and it works well.

H50 BMG I think is better. But nothing wrong with 867.

I would be VERY wary of using it in .338, though. It I actually a 20mm cannon powder and the bulk stuff on the market is from pull-down 20mm. It is “just” compatible with BMG.

but I would not try it in much smaller. I have a lot as well, mainly for 25mm Hotchkiss loads. It works great in those.

Sirhr

 

[Flea21]

W867 is one of the powders I use for .50 BMG and it works well.

H50 BMG I think is better. But nothing wrong with 867.

I would be VERY wary of using it in .338, though. It I actually a 20mm cannon powder and the bulk stuff on the market is from pull-down 20mm. It is “just” compatible with BMG.

but I would not try it in much smaller. I have a lot as well, mainly for 25mm Hotchkiss loads. It works great in those.

Sirhr

I have new stuff that’s been stored in my house for awhile. It’s not the pull down powder you hear about.

 

[Flea21]

Good Evening..
I decided to conduct a calculated and highly controlled experiement with this powder and just thought I’d reach out and share my results with this thusfar…

Im doing this in separate sessions because the nearest range is 1.5 hours from my house. The first goal was to load single rounds to gauge speed and pressure. I ran a quickload simulation using H1000 as a measuring stick and the results were definitely slower than H1000. That said I now had data to go on and I used Quickload again and a little knowledge of slower burning powders to compare against those results. What I found was that Retumbo seemed to be a lot closer to what I experienced as far as speed goes.

Today I took that knowledge and stepped up the loads and received great results. One rifle seemed to be about 80fps slower from the QL simulation and the other was 40-60fps slower from the QL simulation. I was able to get the speeds close to my desired range of between 2700-2800fps. The top load I had was 2664 against a projected 2700 which is a lot better from where I started this experiment. Furthermore, I did a 5 shot group at the start of this test just to get a taste of wheather or not they’ll perform and those were shooting sub MOA at 100yds with an ES of 27fps and SD of 11fps... So there’s definitely an indication of this working out nicely.

The next step is to do a load development with the last two loads and step up another 2.5grs in half grain steps. Lord willing, I’ll find an accuracy node within that range. This will be a 7 shot Load development with 5 shot groups which should deliver sufficient data to find an accuracy node with sufficient speed behind it to stay super sonic out to 1750yds.

 

[Flea21]

Update...

On Sunday, I ran the next test of a 7 ladder step load development with 5 shot groups. The results were awesome!!! As expected, the rifles showed us what they like. Also, the ES and SD numbers were low and speeds reached and exceeded the desired 2700ish without any signs of pressure. I'm excited to report that this powder works and works well. I still have some fine tuning to do with seating depth but at this stage, I was able to put together some decent groups at 100 Yards. The next step is going to be loading the best ones that shot well and seeing if they repeat and then rock and roll from there!

 

[Flea21]

Okay! My apologies for not updating everyone in a bit. I have ran a couple more tests with great results!!

After the last test, I was able to find decent speeds safely. The next test after that I made up some 5 Shot loads. I did 7 steps going up in 0.3gr steps upto 97.80. Yesterday I went out to the range and am happy to report that I hit an accuracy node from 97.20 to 97.80. I know that I clearly pulled a shot in every grouping and am still getting used to the rifle but am very content with the results knowing that this powder is definitely working as I imagined it would. Enclosed are the targets from those loads.

I'm definitely going to load up more of the middle load and confirm accuracy at 100 and then stretch them to 500 and 1000yds and ultimately the goal is to shoot at 1 mile and beyond with this but I'm taking baby steps along the way. Ill update what that looks like when I get a chance to get to those ranges.

I hope this can help someone who might be where I was and is on the fence. As always, I proceed with extreme caution and measure everything multiple times over to the point where its annoying but worth it for safety purposes.

 

[Flea21]

I have a new update. I’ve upgraded the muzzle break to a Terminator TF and the recoil on this rig has dramatically reduced, however this is still a 338 LM and let’s you know once the trigger is pulled.. LoL

That said, I had some trigger time this past weekend and shot a couple groups before plinking at long distance.

I’ve got this rifle shooting a consistent at .5 MOA or better with my hand loads running WC867 powder. Also, the ES and SD are low too.

This load is..
3.017 CBTO | 3.860 COAL
(FYI.. I single feed these as they’re not mag tolerant)
97.50grs WC867
Lapua Brass
CCI #250 LRM Primers

 

[jacklikesbigbores]

I have a new update. I’ve upgraded the muzzle break to a Terminator TF and the recoil on this rig has dramatically reduced, however this is still a 338 LM and let’s you know once the trigger is pulled.. LoL

That said, I had some trigger time this past weekend and shot a couple groups before plinking at long distance.

I’ve got this rifle shooting a consistent at .5 MOA or better with my hand loads running WC867 powder. Also, the ES and SD are low too.

This load is..
3.017 CBTO | 3.860 COAL
(FYI.. I single feed these as they’re not mag tolerant)
97.50grs WC867
Lapua Brass
CCI #250 LRM Primers

How much throat jump are you set at?

 

[Flea21]

I am either .015 or .020 off the lands. I’m not at my bench now but I can check my notes when I get back later and let you know.

Keep in mind though, those loading details are specific to my rifle. If you’re doing this, I highly recommend to do one shoe tests starting waaaay low to be on the safe side of things. Then slowly build up your speed and pressure until you’re content with the results.

 

[jacklikesbigbores]

I did a MV comparison test on our slowest ball powders last summer to determine what the burn rates were in regard to each other
I loaded 4 cartridges each for an average, of 338 Lap with the same loads and this is what I came away with, US-869 was the slowest, Accurate 8700 was next, H-870 was a little faster and WC-867 and Ramshot were pretty close to each other (this is the batch I have, it can very quite a bit from batch to batch)
I load my rounds about the same as you with the jump at .015-.020"
H-870 and AA-8700 are no longer with us but I have enough of both to make some loads up with them. The best group I ever shot was with AA-8700 with a 300g Sierra bullet, but slow. If using H-870, ya gotta reduce by 10% or more if your shooting in the summer heat, it's very "peaky" about temps. When I had loads with this powder, I'd keep them in a small cooler and bring them out about 15-20 minutes before I would shoot them. This was at the range, if I was in the "field" I just down loaded them to lower vel's