PRODUCT NEWS: Shooters World SW4350 Propellant

A newly-formulated old-favorite propellant gets put to the test by Olympian Ken Johnson. READ THE RESULTS

Ken Johnson

I’ve been having dreams about 4350. But not the kind of dreams you’d think a ballistician would have. The book, “The Art of Memory” therein provides clues as to why my brain thought it would be smart to sprinkle this stuff on my ice cream. WAIT! Before you wave your magic finger and go back to Facebook…

Well, sure enough, it’s a useful propellant. Moderately slow. Too slow for .308, but in terms of propellants better suited for higher chamber-to-bore ratios, it’s a wise choice to have on hand. And it seems to be the favorite punch to serve to the Prom Queen (Miss Jezebel Creedmoor) at the Prairie Revival School dance. More soon…

I shot 4350 in .243 Winchester with a 107 Sierra Match King, back when I won the very last 300-Meter 3-Position Rifle event at the Pan American Games, Argentina 1995. I have fond memories of Argentina. And, the accuracy of that 4350 powder.

Our manufacturer has been making 4350-speed propellant for approximately 70 years. They know the burn speed, and they know how to make it right. Recently, they upgraded the chemical stabilizer from 1940s technology to that of the European Chemical Hazards Agency compliant goop. Current vernacular describes this propellant as “REACH Compliant.” It’s good to know that you won’t be poisoned by this powder now, if you sprinkle it on your ice cream… That was a joke. Don’t do that.

Now, for those who’ve followed the history and application of THIS propellant in a parallel universe, you’ll know it to be slightly slower in burn rate than other 4350 offerings. In our analysis, we found that to be largely true.

So…about that dance with Miss Creedmoor… I decided to run a test of our SW4350 data against H4350 data to determine relative accuracy performance. It was a relatively warm July day in the Panhandle of North Florida, a few miles inland from the Forgotten Coast.

The thermometer read 94.5 degrees. The humidity would be classified as “swamp.” Mirage was switching left-to-right, and right-to-left again. Heavy at times, like shooting through a swimming pool, but as easy to read as Dick and Jane. Hornady virgin, unmolested brass. I did absolutely nothing to the brass, other than seat a primer, dump some powder, and cram in a bullet. All charges were weighed to 0.10-grains. Federal 210M primers. Nosler Accubond 130s. Fired at 250 yards. Standard SAAMI 6.5 Creedmoor chamber. I did all the gun plumbing. 1-7 twist 5-R Rock Creek 24-inch barrel. Predator action, torqued to 65 inch-pounds.

Now I’ll grant you, I didn’t shoot hundreds of rounds of each sample. But, I did double-blind the test. So, I didn’t know which ammunition I was shooting. All I knew was “1” went on top, and “2” went on the bottom. And, my apprentice had a good time playing with my head. She tends to do that, especially when “doing the dishes” is on the line! That bride of mine, she keeps life interesting.

Below, the various groups shot alternating between the two samples. According to my results, SW4350 had less vertical dispersion than the H-version.

SW4350 vs. H4350

I can tell you that the mirage was running that day. And I never noticed it boil at all. So, I cannot find cause for the vertical shots. But you be the judge, and let me know your thoughts!

ken johnson

As an added bonus to celebrate the release of the new SW4350, Shooters World Powder is covering your HAZMAT! When you buy 4 pounds of Shooters World Powder, you get FREE HAZMAT on your entire order. This is your chance to try one of the most popular powder types out there, at a better price, with some exciting results!

Click Here to shop all Shooters World Powders!

About the author: Ken Johnson works with Shooters World in the capacity of Ballistics Managing Partner, Laboratory Manager, and Ballistician. In addition, Ken has had a long and distinguished career as a championship shooter both with the USAMU and USA Olympic Team, having won numerous gold, silver, and bronze medals in the Pan American Games, World Championship, and other international events, as well as national championships at Camp Perry. 

16 thoughts on “PRODUCT NEWS: Shooters World SW4350 Propellant”

  1. Too bad you didn’t chronograph the loads. It would be interesting to see if the “vertical shots” was related to velocity or not. While more of a product release posting, I would liked to have seen a more in depth comparison to get a better idea on how it fares in relation to the others and possibly in a couple of different chamberings.

  2. Interesting, but I’d like to see a work up of multiple loads with both powders with the shots chronographed so see if the results hold up. Barrel vibration nodes could account for vertical stringing. I guess I really don’t have to tell you that.

  3. Awesome. Been waiting on this Powder. Started .204 Ruger Loads last week with Match and Tactical Rifle. More to do this weekend, but as of now, Match has upper hand with 204 Ruger loads. BUT, it’s way too early to tell. 3970FPS with 26 Gr Grenades and Match with .27 Groups @ 100 yd. Moving to 34 Gr Dogs today, then 39 BK’s. Slow process with no info on the 204 Ruger Data, but I am liking Shooters World Powders. Gonna order the 4350 today. Developing Loads is the fun part…Thanks Ken, your articles on Shooters World got me interested.

  4. How does this SW4350 compared to H4350 in temperature stability?

    That’s the reason everyone is after H4350, not burn rate. There are plenty of powders that are the same or close enough.

  5. The last time I looked, The Shooter’s World website listed loads for only a few of the most popular cartridges and listed loads by powder rather than by cartridge making it difficult to compare powders. Shooter’s World powder are not listed in any of the loading manuals I have either.
    I think I’ll stick with the proven IMR 4350 which came in DuPont cans when I started reloading.

  6. Your results suggest that the SW powder deserves a look as a contender to replace the H powder. But one of the outstanding features of the H powder (and Varget) is temperature insensitivity. So here is the question: how did you manage your test rounds? Did you keep them cool? Or did you let them equilibrate to ambient temperature? Or did you just shhitem up with no real consideration for how hot the rounds might be getting?

  7. Kenney, in my memory, it’s been over 25 Years. 4350 had one draw back. That was being a slow burn Powder it was a problem in Gas Guns. M1 Garands and M14s. The problem arose in that the peek pressure tended max right about the Gas Port. Was said that it put the Operating Rod to the receiver right out thru the side of the Forend section and Hand Guard. never tried to see as I value my M1 Garand. Might be worth
    mentioning. FITZ..

    1. Hi Bob,

      I’m in communications currently with folks who can help me prove or disprove this issue. Studying it now.

      Please say hello to the friends for me, especially the renegade from a motorcycle gang…

  8. They have released a new reloading manual on their site that several calibers to start with.

    I replaced Varget in my .308 with SWP Precision Rifle and got slight better SD, ES, and accuracy. Also use the Major Pistol in my 125gr SJHP load in my .357 with excellent results.

    I am a fan. Keep looking at my 300 Win Mag and H1000 loads and wonder of that is next or a powder for my AR’s in 223 Wylde, and 7.62×39 to hopefully share.

      1. Thanks. These loads appear to be very similar to my IMR 4350 loads for 6.5×55.

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