Vihtavuori in a 6 gt

Getting a clear answer on this has been interesting. Everything from N140 to N555 has been suggested. I’m still sitting on enough H4350 to not care to try VV, but I’m so curious.
 
I'm very interested in this living somewhere where Varget and H4350 are now banned. N140 up to 105gr and N150 above? I'm going N140 works for everything as I have some and it is at least possible to buy more.
 
N150, 105gr Hybrids. 27" Krieger.

5 shot groups.

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Normally I would think N540 might be a bit fast for heavies, but it seems like it’s working for people. N550 will probably give you a better velocity/case-fill ratio though. N150 will definitely save the throat on your barrel in exchange for some velocity loss, but N160 tends to be a better fit for the 6mm GT/Creed cartridges again giving you better velocity/case-fill ratio.
 
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I will try N140 and N150 at some point when I run out of SWPR in 6GT... and whichever one seems closest to Varget/SWPR is probably what I'll be rolling with for my next couple of barrels. I don't care about max speed/MV at all and case-fill very little.

I'm a Varget/Varget-alike kool-aid drinker at this point, there's something about the faster powders that is magical when it comes to making low SDs easy. I don't think case-fill matters as much as some (incuding me) think/thought (truthfully it doesn't seem to matter at all since I started dropping every single one of my charges to the nearest kernel/flake). After shooting a lot of both, I will probably always choose the faster class of powders over the the slower for the foreseeable future (I don't worry about pressure since I'm not chasing speed).

I only run 32 grains in my 6GT (which some might consider low case fill) and haven't ever seen an SD higher than a 6 over 20 shots.
 
I will try N140 and N150 at some point when I run out of SWPR in 6GT... and whichever one seems closest to Varget/SWPR is probably what I'll be rolling with for my next couple of barrels. I don't care about max speed/MV at all and case-fill very little.

I'm a Varget/Varget-alike kool-aid drinker at this point, there's something about the faster powders that is magical when it comes to making low SDs easy. I don't think case-fill matters as much as some (incuding me) think/thought (truthfully it doesn't seem to matter at all since I started dropping every single one of my charges to the nearest kernel/flake). After shooting a lot of both, I will probably always choose the faster class of powders over the the slower for the foreseeable future.

I only run 32 grains in my 6GT (which some might consider low case fill) and haven't ever seen an SD higher than a 6 over 20 shots.
Interestingly that works fine in pistol cartridges. Most of my most accurate, admittedly low velocity, loads are light loads of fast powders. Whether that translates to rifles cartridges I don't know.
 
Interestingly that works fine in pistol cartridges. Most of my most accurate, admittedly low velocity, loads are light loads of fast powders. Whether that translates to rifles cartridges I don't know.

It's funny you mention that, I have noticed that it's kind of miraculous that my mixed headstamp range-pickup, cranked out at hundreds of rounds an hour Dillon bunny-fart USPSA 9mm is always low single-digit SDs... I never made the connection before, but there might be something to it?

I just have always noticed that all the 6mm cartridges that everyone always raves about being easy to load for and accurate like 6BR/BRA/BRX and Dasher always use Varget or Varget-alikes in their "classic recipes"... using Varget/SWPR in 6GT the same things seem to hold true IME.

...and while I've only tested a couple of hundred rounds of it, 35-36gn of SWPR in 6CM is/was eye-opening: works awesome!
 
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It's funny you mention that, I have noticed that it's kind of miraculous that my mixed headstamp range-pickup, cranked out at hundreds of rounds an hour Dillon bunny-fart USPSA 9mm is always low single-digit SDs... I never made the connection before, but there might be something to it?

I just have always noticed that all the 6mm cartridges that everyone always raves about being easy to load for and accurate like 6BR/BRA/BRX and Dasher always use Varget or Varget-alikes in their "classic recipes"... same things seem to hold true for 6GT IME.

...and while I've only tested a couple of hundred rounds of it, 35-36gn of SWPR in 6CM is/was eye-opening: works awesome!
My theory is the slower powders need a fuller case to get consistent combustion, whereas the fast powders burn so quickly that any difference in pressure is negated. The fast powders may also be less influenced by primers for similar reasons? If N140 works in 6GT with all bullet weights that would be a bonus as it's reasonably easy to obtain here.
The only downside I see is the possibility of reaching pressure before max velocity. As I'm only targeting 2850 FPS that may not be an issue.
 
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N140 may be a bit too fast for heavies - barely 90% case fill and already approaching max pressure.

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N150 is an improvement and probably the better case-fill/velocity ratio

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N160 will give you more velocity with lower case-fill

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And N550 will give you even more velocity for roughly the same case-fill at the expense of faster throat erosion
 
The powder charge for N150 is on the high side for quickload. My real world performance over 3 barrels, 2 of them were bartlein, they ran 2890fps with 32.8g of N150 and the other barrel was a shilen which liked 32.0 of N150 @ 2860 fps.
 
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BulletPowderStart Load gr~Start Velocity fpsMax Load gr~Max Velocity fpsFill
109grN15031.1261334.22831101%
109grN54030.2262633.2283092%
109grN55032.9269636.1293899%
 
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Does anyone know if one has anything over the other as far as temperature sensitivity (N140 vs N150)..?

(...and if someone at Viht IT reads this: add 6GT and Dasher to your load data please :rolleyes: lol)
 
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Both have been pretty stable in my experience, though admittedly I’ve got a lot more years with N140. The only VV powder that has showed me any significant temp sensitivity is N540 - I bounced between it and Varget for years.
 
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Both have been pretty stable in my experience, though admittedly I’ve got a lot more years with N140. The only VV powder that has showed me any significant temp sensitivity is N540 - I bounced between it and Varget for years.

I was reading some of the earlier comments, and looking at the Viht site, and you might be onto something about N160 being worth a try...

Its supposed lower flame temp may help with barrel life, I'm just weary of it being a little too slow to where it loses some of the magic? But it does look promising as an option closer to H4350 than Varget.
 
The general rule of thumb from a VV rep: use N100–series if you’re shooting rapid fire stages and want to prevent the barrel from heating up too quickly, or just to mitigate throat erosion a bit. For everything else, N500-series.
 
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I still think N160 is going to be better optimized for the 6CM, but I don't think it will suck for the GT either. If you have a need for speed in the GT though, I'm going to guess that you'll run out of case capacity with N160 well before you eclipse the speeds you'd get with N150 or N540.

I've got 8lbs of N160 sitting here for my next CM barrel, maybe I will get into it just a bit to see what kind of velocities and accuracy I'll get with it. My 27" Krieger has definitely shown a preference for the H4350 burn rate more than it has the faster stuff like Varget. Sample size of 1 however.