300WSM powder selections

Reloading Tips
1

I am new to reloading and looking to start reloading 300 wsm for a hunting round. I was looking to run a Barnes 190 grain LRX bullet, would anyone have information or ideas on powder selection and or load data ? Barnes does not give a lot of data

2

Hi Buckmaster,

From what I’ve seen discussed across a few reloading forums, the 300 WSM tends to like the “4350-to-4831 burn rate neighborhood” for 180–200 class bullets, and that still holds true when people are trying the 190 LRX. The common suggestions you’ll see come up over and over are H4350/IMR4350, H4831SC/IMR4831, and Alliant RL17/RL22, with some folks also experimenting with slower options like H1000/RL26/IMR7828 depending on barrel length and how much room they have (freebore/mag length).

A couple practical points people keep repeating when pairing a long, mono bullet like the 190 LRX with the short 300 WSM case:

  • Case capacity gets tight fast. With heavy monos, you can run into compressed loads and/or pressure earlier than you’d expect compared to cup-and-core bullets of the same weight. People often mention pressure signs showing up “suddenly” when chasing velocity, so a conservative work-up is the norm.

  • Barnes seating guidance matters. Barnes themselves note these bullets often shoot best with a decent jump (not jammed), and many users report starting around that guidance and then tuning in larger increments rather than chasing tiny changes.

  • If you’re new to reloading, the safest “path of least drama” is to pick one of the commonly proven powders (H4350 or H4831SC are the two that show up constantly), use published data, start at the manual’s starting load, and work up while watching for pressure. If you can’t find exact “190 LRX in 300 WSM” data in one place, people typically choose data from the bullet maker first, then cross-check against powder-manufacturer data for similar bullet weights/styles.

Also worth noting: Barnes actually does publish a 300 WSM PDF that includes the 190 LRX (it’s easy to miss because it’s a separate document). I’d strongly recommend using that as your primary reference rather than relying on forum-repeated charge weights.

Sources (URLs)
https://barnesbullets.com/content/barnes-loaddata/rifle/308/300-Win-Short-Mag.pdf
https://barnesbullets.com/load-data/
https://barnesbullets.com/faqs
https://sierrabullets.com/content/load-data/rifle/308/300-winchester-short-magnum-%28WSM%29.pdf
https://www.longrangehunting.com/threads/h4350-for-300wsm-anything-better.366577/
https://rokslide.com/forums/threads/300-wsm-powder.339385/page-3
https://www.hunttalk.com/threads/300-wsm.320491/
https://forum.nosler.com/threads/300-wsm-load-data.29893/

https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/19797590/powder-of-choice-for-300-wsm

https://precisionrifleblog.com/2020/03/21/bullet-jump-and-seating-depth-reloading-best-practices/

3

6.5 Staball works great. I’m shooting 208gr bullets. ES/SDs are great. Temp stable powder, easy to find and price is good.