VV lot to lot consistency

[Earnhardt]

Ya, Reloder 16 works great in 135*F temp swings... I'll compare my new VV N570 loads I built up this summer, too the cold winter temps, and see how they hold up

 

[XTR]

@Laurie I've shot my N150 load in temperatures from the upper 40Fs to low 50Fs, early mornings in Raton and matches in New England to 100F+ in Shreveport LA. The load was solid in all of it. I'm sure it's faster at 100F but the load shot flat.

 

[Capt. Oblivious]

I use N160, N540, N550 and N560 in all my rifles and I probably can't shoot good enough to notice a difference from lott to lott, have shot them in 40F in the cold winter mornings rite up into the 90s without any problems. Im still a little new to N540 but it looks to follow the same path as the other. The accuracy nodes with N550 and N160 is so wide in the rifles I use them in you can drive n truck though that node

 

[barefooter56]

Where? I've been laboriously working my way through all the individual powder characteristics descriptions and there are one or two pretty broad references to temperature stability, but nothing at all in this aspect for most.

In the introductory / overview blurb to the rifle powders, there is among the list of attributes:

⇒They’re extremely temperature stable
Temperature stability in powders has always been a consideration, but with the recent improvements in Long Range shooting, it has become a factor of major concern to shooters. Firing at long ranges places greater demands on ammo, equipment and the shooter himself. Enabling a shooter to meet these demands means refining the process, and eliminating those variables which reduce hit probability. The production of increasingly temperature insensitive propellants allows for greatly reduced Extreme Spreads and Standard Deviation, which translates directly to less vertical dispersion on target.

Every propellant manufacturer I can think of has made the broad claim that "our products are extremely temperature stable" for years .... and that includes manufacturers and some of their grades that have been anything but!

I saw a former Capstone employee say in a post on this forum maybe 18 months back that it was a great trial to Capstone that Viht won't get up and shout about what they've been doing in this respect over the last few years risking the impression they're being left behind by competitors. (Also, no fancy marketing name like 'Extreme' or 'TZ' .... but he didn't say that!) I'd just like to know which grades have 'changed' and if so by how much. Do any enhancements apply to both N100 and 500 ranges and if that's a 'yes' do they apply equally?

The other product enhancement that all manufacturers are chasing - decoppering / anti-fouling does merit a large section of the website including before and after treatment 30-06 bore photos taken after 50 and 100 rounds. Why not temperature stability too if there is a significant across the board improvement?

N150 has always been a very stable grade and it is one of the few where temperature gets a mention in the the website's more detailed description, and as far as I can see the only one whose description suggests a reformulation / enhancement:

Combining Vihtavuori’s latest decoppering technology and enhanced temperature stability, N150 is a tremendously versatile powder with a lot of options even for the demanding handloader.

Don't get me wrong. I'm a great Viht fan and very heavy user of some grades, especially N150/160/165 and their performance and lot to lot consistency is and always has been excellent. (I've used N160 since it was introduced onto the UK market in 1985 many years before any Viht products were exported to the US. That's getting on for 35 years of satisfied continuous use.) I'd just like a bit of clarity here, and I'm sure I'm not alone.

Laurie,
Kevin is right. The Finns are very low key individuals. So " enthusiastic" marketing is not there style. They prefer to let their products speak for themselves. The N-500 series of powders AND N-150 are temperature stable powders. All now have the de-coppering agent added to them. If more powders become classified by VIHTAVUORI as temperature stable we will let you all know on our websites as soon as they are announced. Not to detailed Laurie. But I hope it helps! And thank you for using our VIHTAVUORI powders!

 

[Marksman63]

And what about N-140? It should be more stable than N-150

 

[Laurie]

The N-500 series of powders AND N-150 are temperature stable powders.

Many thanks for the clarification Phil. These upgrades are excellent news.

 

[Dusty Stevens]

And what about N-140? It should be more stable than N-150

Why would that be?

 

[Jdne5b]

And what about N-140? It should be more stable than N-150

Also wondering about N140. Seems to be pretty stable, but have only chrono'd in ~25deg differences.

 

[urbanrifleman]

New Vv n160 is nothing like the 2015.

 

[urbanrifleman]

I shot my 2015 n160 243 load in the panhandle shooting p dogs. Early morning truck air conditioning ammo 70 degree temp shot with nice round primers.

By the afternoon at 105 degrees and ammo in the sun blew case rims off and blew primers.

True story.

 

[Laurie]

New Vv n160 is nothing like the 2015.

Apparently 'faster' or 'slower' than older lots?

 

[urbanrifleman]

Apparently 'faster' or 'slower' than older lots?

New 2018 lots are way faster.

 

[Down South]

@Laurie I've shot my N150 load in temperatures from the upper 40Fs to low 50Fs, early mornings in Raton and matches in New England to 100F+ in Shreveport LA. The load was solid in all of it. I'm sure it's faster at 100F but the load shot flat.

Yep, I remember that day in Shreveport well. It was a wee bit toasty that day and your load was hammering.

 

[Marksman63]

Why would that be?

According this table

https://i.imgur.com/33XPgx3.jpg

 

[Down South]

On their web-site they list them ALL... And one of our shooters in AZ has tested N150 from winter to summer with excellent results as far as temp stability goes. He is using it in his .308 for F-T/R..

A few of us FTR shooters have been using N150 with good results.

According this table

https://i.imgur.com/33XPgx3.jpg

After shooting quite a bit of N150 since 2014 in two different .308 FTR rifles I have a hard time believing this chart. N150 is VERY close to Varget burn rate in reality, not close to H4350 and seems to be pretty dang temp stable. I've shot it in 100 degree temps in summer time matches and 30-40 degree temps in winter matches here without any issues. Just my .02

 

[ShootDots]

A few of us FTR shooters have been using N150 with good results.


After shooting quite a bit of N150 since 2014 in two different .308 FTR rifles I have a hard time believing this chart. N150 is VERY close to Varget burn rate in reality, not close to H4350 and seems to be pretty dang temp stable. I've shot it in 100 degree temps in summer time matches and 30-40 degree temps in winter matches here without any issues. Just my .02

Hello Jade! I have come up with my own "chart" for many powders. "My" chart is based on years and years of experience. As you postulate, the VV chart is incorrect! On a fast lot of Varget, VV N150 is a shade slower. However, on a slow lot of Varget, N150 and Varget are right on top of one another. It is NOT dependent on the "consistent burn rate of the Viht powders", it is more based on the INconsistent burn rate of the Hodgdon lines!

 

[rardoin]

Yea...I would put N160 closer to H4350 for sure.

Robin

 

[Laurie]

A few of us FTR shooters have been using N150 with good results.


After shooting quite a bit of N150 since 2014 in two different .308 FTR rifles I have a hard time believing this chart. N150 is VERY close to Varget burn rate in reality, not close to H4350 and seems to be pretty dang temp stable. I've shot it in 100 degree temps in summer time matches and 30-40 degree temps in winter matches here without any issues. Just my .02

As you postulate, the VV chart is incorrect! On a fast lot of Varget, VV N150 is a shade slower. However, on a slow lot of Varget, N150 and Varget are right on top of one another.

These findings tally with my own. I've used N150 off and on in 308 getting on for 20 years now and long before F/TR started. This was back in the days when the UK sling rifle load was 155gn Lapua Scenar or older SMK, Lapua (large primer) case and a really stiff load of N140. People looked at me a bit oddly when I said I used N150 not 140 - way, way too slow they were sure. Even with 155s, I got better groups with N150 and maybe lost a bit velocity. (Since then, I've seen a 155.5 Berger BT / small primer Lapua case load cranked up to MVs I wouldn't have believed in an F/TR rifle if I hadn't seen the Magnetospeed monitor screen in front of my eyes ... and it involved a heavier charge than I'd have ever reckoned you could get into the case, but that's a different story!)

Likewise, I've long reckoned that N160 is nowhere near as slow burning as IMR-4831 that it's shown against on Viht's chart - not far from 4350 I'd say. This is backed up by Norma's table in it's 2nd edition reloading manual that uses a common 308 Win case / bullet / charge weight load of different powders showing both pressure and MV as a figure against a baseline 100 for each value using IMR-4350.

Taking the two Viht powders against IMR-4350 you get on this basis:

.............................................. Pressure ........ Velocity

IMR-4350 ................................ 100 .............. 100

N150 ...................................... 118 .............. 115.7

[Allt. Re15 / Norma 203-B] ....... 133.7 ........... 120 (Varget not in the table, Re15 closest equivalent)


N160 ...................................... 107.5 ........... 102.1

IMR-4831 ................................ 93.2 ............ 98.3

[H4350 .................................... 94.9 ............. 100]


This is a pretty old table and hasn't been updated since the 1st edition of 15 or 20 years ago. Also like all such charts / tables it suffers the inherent flaw of the use of a single charge weight within a common combustion chamber volume irrespective of how well the powder matches that, and in this methodology, expansion ratio too as it uses a cartridge in a barrel.

If, as Medic505 and Urbanrifleman say, recent lots of both N150 and 160 are faster than older ones, then Norma's results will be conservative and should show the pair as even further removed from IMR-4350 and 4831 respectively.

Interesting!

 

[Down South]

2015 44.7 N150View attachment 1123185

Dean, I did some chrono testing a couple days ago. Berger 200.20X bullet was running 2647 ftps avg. with 44.3 gr N150. Lot of powder was manufactured 12-1-2015

 

[Medic505]

Dean, I did some chrono testing a couple days ago. Berger 200.20X bullet was running 2647 ftps avg. with 44.3 gr N150. Lot of powder was manufactured 12-1-2015

I'm shooting the 200 hybrid just to clarify.