.338 Win Mag subsonic loads

[Nick4050]

To start, I understand that this is a horrible cartridge to load subsonic.

I have a .338 win mag brush gun with an Alaskan360 can on it. I'm wanting to load some subsonic rounds just to have for fun plinking around the cabin. I'm thinking a 300 grain projectile, something cheap like an interlock or speer sp. Does anybody happen to have any experience with loading this cartridge subsonic that could help offer a starting point for powder/charge?

I've done a bunch of .308 subs with Titegroup, and it seems to work really well. I know that position sensitivity is a concern with the 338 WM's larger case capacity, but Titegroup seems to be pretty insensitive.

 

[A382DWDZQ]

I would take a look at the Lyman Cast Bullet Handbook. It has 338WM in there, but for 249gr as the heavier. You can take a look at the 300WM & 375 H&H for comparison. The Lee Modern Reloader 3rd edition has some info on reducing loads, but I’d guess the 4198 and 4895 powders would probably get you some reduced loads. Hodgdon has h4895 loads for the lighter bullets.