Wanting more velocity out of 338 WSM

[ruby76]

I am at 2.945" and was at 2650 with 59.5 gr H4350 with no pressure and sticking cases. I was 62.4 gr h4350 on first firing at 2760.

I was 62.3 grains of H4350 F210M 2770 at a coal of 2.887 at .015 off

 

[bobinpa]

VARGET will be your friend. I've been where you are. I love WSMs and H4350 is my go to powder in my 300 WSMs but it's too slow when you get into bigger calibers. At least that was my experience.... In my 338 WSM it gave fair accuracy but slow. I hit pressure quickly while trying to get up to a desired velocity. I am using 63 gr of Varget behind a 215 Sierra Game King at just a touch over 2900. My average velocity is 2910. I run Varget in my 358 WSM too. It pushes a 225 Sierra Game King at 2840ish.
The 338 has a Hart barrel and the 358 has a Lilja.

Don't start with my load. It's very close to MAX pressure. Back off of that and work up...

I hope this helps!

 

[bobinpa]

I am using magnum primers, same F210M

Just an Fyi, a F210M is not a magnum primer. F210 is a large rifle primer. The M is for match. The Fed 215 is the magnum primer and a Fed 215 M is the magnum match primer.

 

[FEENIX]

I am at 2.945" and was at 2650 with 59.5 gr H4350 with no pressure and sticking cases. I was 62.4 gr h4350 on first firing at 2760.

Your statement does not clarify whether you had pressure at 62.4g H4350 2760 FPS; if so, drop your charge to 61.4g H4350 and re-evaluate for 2700 FPS. I would take accuracy over velocity anytime, especially when there is only a 50 FPS difference from your 2750 FPS goal. Whatever safe velocity you end up with, adjust (dope) accordingly to your intended purpose at range X.

I'll be happy with a consistent 2700, I think that should be achievable.

 

[MagnumManiac]

Haven't read all pages.
I built my first 338-300WSM on standard length actions in the early 2000's.
We could not get within 100fps of regular 338WM velocities with bullets from 200g to 225g, 250g bullets fell short by 150fps.
I am sure this is why Winchester never did a factory 338WSM.
The only powders we could get to work were RL17, much later on, and Win 780 Supreme (now discontinued). This powder is the same as 785, 780 & one of the other brands which I forget it's nomination.
H4831 works, but velocities are slower again. RL19 also worked, but again velocities are slow.

I hope you can delve into a powder that boosts performance because we never did, I haven't touched a 338-300WSM since about 2013/14.

Cheers.

 

[Earnhardt]

By looking at your pics, and seeing how far out the bearing surface of the bullet, is...

I'm guessing your bullet is jammed, and causing pressure spikes

Unless you have a freebore reamer of .100" to .125" or so.

 

[Roperboy87]

Not sure if it will work for 338wsm but a buddy shooting 300wsm 225 grain pill shoots n540 gets plenty of speed and tiny groups at 600 yards and 1000 yards

 

[gpaw94]

Huh?…
Please provide some load data for a 338 WSM with N570.

https://img1.wsimg.com/blobby/go/b4083d55-887e-47d6-93bd-312cd4a323d2/Sherman%20Load%20Data%202_28_24.pdf

Take a look at the 338 Mega from Sherman. The mega has just a tad more case capacity over the wsm. If you were running a 16-18" barrel then a N555-N560 would be more appropriate. With a 24" barrel there is plenty of length for the slow burning powders to do their job.

 

[Seabeeken]

Played with it in GRT a bit. No VV powder can get you to 2700 fps but if you are set on VV, then N-555 was the best option. N-565 is just too slow burning. Reloder 16 and 17 can get you to 2700-2750 with max charges