Load testing: VihtaVuori N350 powder

[Wobbly]

I've loved all the single-base powders from VihtaVuouri in the N300 series, especially N320 and N330 for a long time. They simply perform fantastically in every area. So of course when I was at the "gettin' place" one day I saw a can of N350 and decided to try it. This was, according to my date code on the can, way back in 2012.

So why has it taken so long to do some testing ? That decision was made before looking at the specs. N350 is very slow. In 9x19 Luger it is somewhat useless because Max Loads for N340 and N350 are within 5fps of each other for some bullets. It's generally on par with 3N37, and runs bullets 30 to 60fps faster than N340 in calibers 38 and larger. I'm not sure what I was thinking that day, other than being completely mesmerized by that black can with the purple top.

I only shoot one magnum pistol, a 357, and even then I only shoot maybe 20 shots per year. Mostly I use that gun for testing and target practice with 38Spcl. But, I finally did get around to doing some 357 test loads.


Background
Caliber:    357Mag
Bullets:    158gr RMR plated flat point
Brass:      Mixed
Powder:    Vit N350
Max Velocity:  1333fps per the Vit load manual
Primer:     CCI 500
Pistol:      Ruger GP100-6"
Distance: 30ft measured and bench supported
Qty:        6-12 rounds each, slow fired
Weather:  70F, clear and sunny, afternoon
Chrono:    ProChrono DLX

Load      Avg Vel           SD
8.5gr        1163                 32
8.7           1185                 18
8.9           1224                 7

Rocky Mountain Reloading 158gr
Plated, conical flat point with rolled cannelure
> Length    = 0.626"
> Diameter = 0.358"

NOTES:
- Metered nicely like other N300 series, slightly larger grain size
- As clean as other N300 series
- Low flash
- More of a 'push' than an abrupt recoil. 8.5gr felt good.
- Nice, clean, cool burn with no ash or trash
- All my shots strangely pulled to the left, while this gun is dead-on with 38Spcl. Probably need to work on my grip.
- TQ-2 target black measures 2.3 inches
- Reminder to self: try this in 10mm



Accuracy results for 8.5gr


Accuracy results for 8.9gr

[Fuzzy Sights]

Love this powder in 357 Sig and 40 S&W.  Wish I had some 10mm brass to try it in. 

Thanks for the information, may have to give it a try in 357 mag

JW

[timetofly]

I’ve noticed that3n37 seems to have a smoother recoil compared to CFE PISTOL.  At least in 38spl. Going to load some 357 mag to see if it still holds true. I’ve read that vi powders seem to be smoother than other powders. Is this your experience also?

Thank you for the research and report.

[Wobbly]

I’ve read that vi powders seem to be smoother than other powders. Is this your experience also?

I know it's true of the N300 series powders. They are "single-base", meaning they do not contain nitroglycerin. Common "double-base" powders contain some percentage of nitro that boosts chamber pressure, makes them recoil abruptly and burn much hotter. The absence of intense heat makes single-base great to use with lead bullets.

Single-base used to be more common, but sources are dwindling. IMR used to offer 7625 and PB. Accurate used to offer Solo 1250 and Solo 1000. Nobel Sports offers a "Ba" series, not widely sold in the US. Then we have the Vit N310 through N350 series.

Next time you're in a load manual, look at the chamber pressures 7625 generated in shotgun. It took maybe 5% more powder, but to achieve equivalent velocities the pressures were 5,000 to 8,000 psi lower !! That's the absence of nitroglycerin.

[SoCal]

Where N-350 looks good in 38 SPL is with heavier bullets 158 and 180 grain where it shines at making them move pretty fast, not 357 mag. fast but very respectable.

For example 158 gr Speer HP MAX.  6.3 gr gives you 1013 FPS., in their  (6½”), 1 in 18” twist test platform.  while an H&P HP 180 gr MAX 6.3 grains  gives you 1017 FPS.