QuickLoad Data for 300 WSM 175 LRX loads in Shorter Barrels?

[CoolhandLuchs]

I've been looking over data here for a while, and there seems to be quite a bit for the 300 WSM, but mostly 24" barrels. I built up a new elk rifle, but with a 20" barrel that I'm planning on running suppressed, once I overcome my analysis paralysis and things become more available. I've been starting load development with StaBall 6.5, but am wondering what choices there are for clean burning loads in shorter barrels? (trying to keep as much carbon out of the can as possible)

There are a lot of rabbit-holes out there, and I'd like to avoid as many as I can, and I'm hoping some QL data might steer me in the right direction.

Been looking at powders like:
StaBall 6.5
H4350
VV N555
RL 16 (can't find any)

Specs:
300 WSM | 3.2" Action Length | 20" Barrel Length
Barnes 175 LRX
ADG Brass
COAL: 3.10

Looking for:
Temperature stable (Colorado has wild temp swings in the fall)
100% Burn Rate/Clean Burning Powder in a short barrel
Goal of 3000 FPS, likely ambitious, but hey, why not?

Thanks for any advice or data you can give me!

 

[JaimeAdams]

In my opinion for 300 WSM with 20 barrel, you can try powders like StaBall 6.5, H4350 and VV N555 for clean performance and temperature stability. Here is my suggestion, hope it helps you.

smash karts​

 

[CoolhandLuchs]

Thanks @JaimeAdams, that's the plan. I managed to snag a couple pounds of N555 and even a pound of RL16 from Midway. I'll try those, if UPS ever delivers the order. I currently have a test set up with StaBall 6.5, but I don't think I'll have time to really dig into it before the season starts.

I did manage to do some testing with H4350 and the 175 LRX in the area I'll be hunting (7600' altitude). There appears to be some promise with H4350 in the short barrel: 65.7 grains gave a 3 shot average of 3025 FPS with an SD of 1.1 and an ES of 2.0, definitely worth another look. No signs of pressure, and in my previous ladder I didn't hit pressure signs until 67 grains. Keep in mind, I'm loading a COAL of 3.10" vs SAAMI max of 2.86" and my rifle has a lot of free-bore. These loads are likely over-pressure in a standard chamber.

 

[terrificheavily]

Powders to Consider
StaBall 6.5:
Pros: Known for its temperature stability and clean burning properties.
Cons: May not achieve the highest velocities compared to other powders.
H4350:
Pros: Excellent temperature stability and widely recommended for short barrels. Many users report good performance with 175-180 grain bullets in 20" barrels1.
Cons: Availability can sometimes be an issue.
VV N555:
Pros: Clean burning and temperature stable. It’s a good choice for achieving consistent performance in varying conditions.
Cons: Can be harder to find and more expensive.
RL 16:
Pros: Known for its temperature stability and good performance in short barrels. Users have reported achieving near 3000 FPS with 175 grain bullets2.
Cons: Availability is a common issue.

Load Data and Performance
H4350: Users have reported achieving around 2900 FPS with 175-180 grain bullets in 20" barrels1. This powder is often recommended for its balance of burn rate and clean performance.
StaBall 6.5: While it may not reach the highest velocities, it is a solid choice for clean burning and temperature stability.
VV N555: Offers a good balance of clean burning and performance, though specific velocity data for 20" barrels is less commonly reported.
RL 16: Some users have achieved close to 3000 FPS with 175 grain bullets, making it a strong contender if you can find it2.

Tips for Load Development
Start with H4350: Given its popularity and reported success in similar setups, it might be a good starting point.
Monitor Pressure Signs: Always watch for pressure signs as you work up your loads, especially with shorter barrels.
Consider a Chronograph: Using a chronograph can help you fine-tune your loads to achieve your velocity goals while ensuring safety.

Conclusion
For your 300 WSM with a 20" barrel, H4350 and RL 16 seem to be the top recommendations based on user experiences and your requirements for clean burning and temperature stability. Achieving 3000 FPS is ambitious but not impossible with careful load development.

 

[CoolhandLuchs]

It's been a couple of years (geez...) since starting this, just thought I'd share a few things I've found:

The H4350 175 grain LRX load is holding up very well. From 09/2024 - 10/2025, I've recorded 14 rounds at different altitudes (5000 - 7500 ft) and conditions getting an average velocity of 3033 FPS, 23.5 ES, and 8.8 SD. Needless to say, this is my go-to load.

After spending too much time trying to use the 212 grain ELD-X for a "heavy" load, I've given up and tried the 210 grain ABLR. Results are early, but the barrel seems to like the ABLR better. I had high hopes for VV 555, but, I've settled on H4831SC for around 2805 FPS out of my 20" barrel. I'm not sure about the overall burn efficiency, but I'm getting very good velocity and zero signs of pressure.

For reference, the Hornady 212 ELD-X load for 300 PRC is listed as 2860 FPS on the box, and that's with at least a 24" barrel.

I'm not going to share the charge weights, I'm using an XM+ (3.2") medium-length action with a long throat. My charges won't be safe in most rifles, but, hopefully the powder/bullet combos can guide somebody down a good path in the future.

300 WSM | Barnes 175 LRX | H4350 | ADG Case
Average velocity: 3033 fps (20" barrel)
COAL: 3.100"
BTOL: 2.440"
Jump: ~ .120"

300 WSM | Nosler 210 ABLR | H4831SC | ADG Case
Average velocity: 2805 fps (20" barrel)
COAL: 3.160"
BTOL: 2.485"
Jump: ~ .075"

 

[Brobb]

Based on my recent experience with a Christensen 20" barrel and my opinion, based on listening and talking to people way smarter than me when it comes to reloading, is even though you aren't seeing signs of pressure, I'd bet that load at 3033 fps load is over SAAMI pressure. And that's been something I've wrestled with for years. While I do think it's cause for caution and knowing brass life or gun life might be compromised, how big of a concern is it? I also believe, by the time pressure signs are observed, the load has been over pressure for a bit. As a side note, I'm using Gordon's Reloading tool as a guide for where expected pressure is and then calibrate based on observed velocities.

In the 300 wsm I'm currently working on with 180 grain partitions, I've shot 150 rounds testing H4831sc, IMR4350, RL16, RL17, RL23, N560, N150. I seemed to be over SAAMI pressure 2850 range. So after my tests, three loads to decide on (all at or slightly below 1 MOA at 200 yard test):

Most accurate RL23 @ 2775 FPS
Next accurate RL17 @ 2820 FPS
Equal to 17. IMR4350 @ 2875 (over saami pressure)

 

[CoolhandLuchs]

All valid points, and the only way to really measure pressure would be to install a gauge, which requires ruining the barrel. Handloading is always an educated guessing game. I usually try to do a ladder test to find ANY pressure signs first, then back down a bit. After two years, my first batch of ADG cases is still going strong (no signs of wear or loose primer pockets), but will get retired soon out of an abundance of caution. I did a lot of learning on those first 50 cases.

What's your overall cartridge length? If you're using SAAMI spec (2.86" COAL), then your results will be different than mine. I can load out to 3.2" COAL, which allows more case volume, which lowers pressure with the same powder charge. I'm also jumping my bullets quite a bit, which helps keep pressures in check as well.

Even cross referencing load data, I've seen the max powder charges vary quite a bit with the same bullet/powder combo, so there's always a bit of "reading the tea leaves". For example:

• My 175 LRX/H4350 charge weight is well below Barnes' load data max charge, but inline with other companies' max data. Even with my longer overall cartridge length and ample freebore, Barnes' published max load would not be safe in my particular rifle.
• My 210 ABLR/H4831 charge is over any published max I've found, but appears completely safe by any pressure-sign metric I can see or feel. I would be comfortable working up further, even though it could be over SAAMI max pressure, but I see no reason to take chances.

(I think part of this is that my non-standard COAL/throat allows greater potential gains for heavier bullets, as shorter bullets don't intrude into the case as far, so I don't regain as much case volume.)

As another example, I just worked up a 6.5 Creedmoor load (41.5 grains RL16 with a 142 ABLR) that gives very different results using Federal cases. Small primer cases are good to go, give expected velocities, and the bolt lift is normal. Large primer cases give 75 FPS more velocity, very flat primers, and heavy bolt lift. Two takeaways: case construction matters and always work up. Most max loads with 6.5 Creed with 140ish grain bullets and RL16 seem to be around 43-43.5 grains. 41.5 should be more of a starting/mid load, but it's max for my setup. I guess it just means my powder will last longer.

I'm not arguing with you, I'm a big fan of safety, but the sad reality is there's no real way for us regular folks to accurately measure pressure. GRT is a great resource, but not infallible, and the load data books vary using standard SAAMI setups. For me, it's a lot of educated guessing and starting low, then working up. I'm pretty conservative with my reloading, and I look for balance and consistency in my loads. It's about finding what makes sense and what you're comfortable with. You have to decide (intelligently) what the concern level is for your specific rifle and load.

My 300 WSM is a bit of an odd duck (which is why I like it), but it does require that I experiment a bit and pay attention. My setup satisfies my curiosity about what that stubby little cartridge is capable of when given room to run. That being said, I would never allow someone to use one of my handholds in their rifle, bad things would be very possible, if the round chambered at all.

 

[Brobb]

Thanks for the detailed reply. Certainly no intent to challenge any of your findings. If it came across that way, apologies. I geek out over the reloading and always looking to learn. Being over pressure has been the most challenging thing to understand. There are certainly so many variables that go into the equation.

I typically start out every new load, bullet, powder combo with a ladder test as well, looking to find the pressure signs so I have that top line I wouldn't go over. Last year a friend suggested watching the Little Crow Gunworks videos. A lot of what he said made sense to me and I've incorporated that into my process. The good part is I shoot a lot and generally develop as good a,load as the gun will shoot. The bad part is I spend a lot of money doing it

This particular 300WSM, seems to have decent room to seat bullets farther out. My notes say, 2.8100 to the ogive and I'm loading at .010 from the lands. Need to check that again when I get more bullets to make sure. It's been a fun gun to shoot for sure.

 

[CoolhandLuchs]

No challenge taken, no apologies needed. I've been working on my 300 WSM for about 3 years now (when I have time and money), and I tend to be a bit long-winded when talking about it. You had a great point about "how big of a concern is it", and that's always a balancing act, like most things.

It's fun to experiment and nice when some of your hunches bear fruit. Good luck with your journey, it's a fantastic cartridge, and worth the work.