VV N140 temp sensitivity

[JFrank]

Am I reading that wrong? 0F to 53 degrees! 12fps increase? You sir, have the holy grail lot! I hope my 2023 lot does the same. Cannot wait to try it.

And I get what you are saying about following the target results over getting too worried about FPS. For me I guess the fps is a mental thing. It sits there in the back of my mind. I need to let some variables go. Or like you say trust the target. And I can do that by running the test over and over again until I build that trust. I think that's what I'm gonna be doing this spring!

I can’t say it’s the holy grail or anything else. I posted todays numbers so for what they’re worth IDK you tell me.
Just to add a thought, I have several pounds of N140 and I’m not convinced I'm going to change from H4895.

 

[Dave M.]

Math was never my thing. You do the math.
Today we had 26 degrees 85% hum
Yesterday 31.5 shot 2883,2887,2896
Today 2882,2870,2881
Zero degrees 31.5 shot 2890,2886,2901

Humm, no input ? I’ll just assume I’m being called untruthful or misleading.

Relax brother. I never called you a liar or said you were being untruthful. I merely said your results didn’t match mine or others that have posted regarding N140 and its temp sensitivity. Clearly, you have a better batch of N140 than I have. I’ll have to get the lot # on my powder when I get home tomorrow. Care to share your lot # of N140? Thanks. Glad N140 is working for you, I’ve just recently started working with it and I like the results thus far.
Dave M

 

[avidflyer]

Relax brother. I never called you a liar or said you were being untruthful. I merely said your results didn’t match mine or others that have posted regarding N140 and its temp sensitivity. Clearly, you have a better batch of N140 than I have. I’ll have to get the lot # on my powder when I get home tomorrow. Care to share your lot # of N140? Thanks. Glad N140 is working for you, I’ve just recently started working with it and I like the results thus far.
Dave M

i've seen cold-weather produce no variations, and positive temperatures create very big deviations

 

[Dave M.]

i've seen cold-weather produce no variations, and positive temperatures create very big deviations

Not my experience either. From 28F to 48F, I saw 36fps increase. Not very consistent in my book. I’ve repeated the test between 48F and 60F and I saw a 22fps increase, so a nearly identical fps/deg F. Perhaps my lot of powder is truly a really bad one (I will check the lot # when I get home tomorrow).

Dave

 

[Kiwi Palma]

Not yet because I haven’t been able to take it out to 600 yards yet, but the 100 yard groups look promising. My main concern is the instability of the N140 powder which I was always told is very temp stable (certainly not my finding nor those of a few other members using this powder.) I can tell you the N140 cleaned like a dream, but in all fairness, I’m used to cleaning RL-15, which is by far the dirtiest powder I shoot.
Dave

Hi Dave,

Use VV N140 as my primary match load powder for .308 155grn Palma loads. Used it in the cold and wet conditions in Wellington to the hot and dry Gisbourne with no issues with its temperature stability for years. Several thousand rounds loaded and the ony time I had a problem with the temperature affecting the rounds performance was when the rounds got left out on the mound in Gisbourne in 30°c+ conditions and that required a long soak time - had no over pressure signs and it was likely also the rifle got a little bit too warm as well.
Definitely cleans up well - makes ADI2208/Varget look dirty, also find it is gentler in recoil for same velocity and very consistent between lots. So far have lots from 1993 through to 2015 used and loads have been consistent @45.5grn for LRP and 46.0grn for SRP. Before someone asks, we are at the tail end of the supply chain and then some for this powder with shipments only every few years so don't have every lot to buy and buy it by the case when I find it - or somehow end up with the case contents.
With the temperature charts, if it is done in a lab then the results will be just for round temperature in a very controlled environment not for the other changes that happen on the range as well. It is good data for ballistic profiles but needs to be taken with a grain of salt when it hits reality of a consistently changing environment like different components being used like the primer and its profile.

 

[Mulligan]

Math was never my thing. You do the math.
Today we had 26 degrees 85% hum
Yesterday 31.5 shot 2883,2887,2896
Today 2882,2870,2881
Zero degrees 31.5 shot 2890,2886,2901

Humm, no input ? I’ll just assume I’m being called untruthful or misleading.

How do the group sizes compare between temps?

The reason I ask is, I run N-135 in several of my rifles and did this sort of comparison with 135. My velocities were moving with atmospheric conditions, but the tune was stable. Said another way, the tune did not follow velocity.
I posted this comparison on the forum to show what my testing was indicating and ask a few question.
CW

 

[JFrank]

Clay,
The group size doesn’t change that much at 500 yards. Three shots average about an 1.25 -1.5 but the conditions change the shape quite a bit as I don’t try to compensate for wind rather try and find a spot and send them.
I don’t know that 1.5 is going to be competitive at a grand. Probably not..
I’m testing H4895 high node today.

 

[JFrank]

Relax brother. I never called you a liar or said you were being untruthful. I merely said your results didn’t match mine or others that have posted regarding N140 and its temp sensitivity. Clearly, you have a better batch of N140 than I have. I’ll have to get the lot # on my powder when I get home tomorrow. Care to share your lot # of N140? Thanks. Glad N140 is working for you, I’ve just recently started working with it and I like the results thus far.
Dave M

Dave, your post prior to your editing certainly took that path, my apologies for getting edgy, I’m somewhat sensitive to suggestions of untruth posts or lack of integrity.
Since I’ve joined I’ve learned a lot and thanked everyone here with my main goal to be truthful and respectful, secondly help anyone as I’ve been helped and show my work.

Again my apologies.
Jim

 

[Dimner]

Jim,

How long did you let you ammo accumulate to temps before you shot in each condition?
I do not mean this as questioning your testing, just wondering the particulars of your test as I try to contemplate how it relates to an application for me.

For example, when I temp test, I leave my ammo overnight on my back covered patio then shoot first thing in the morning. I note the temp before dawn and the temp being when I actually shoot. I mainly temp test for hunting purposes, so I feel this best replicates what my ammo will be like in Nov as I sit in a blind for hours. My longest shot has only been 230ish yards, but I like to have the data for confidence in case that 400 yard shot comes along. Probably never will, putting the hunter/blind in the right spot is far more effective than long range hunting.

If I were making competition loads, I'd probably change my process in a manner that I think would approximate conditions at a comp.

 

[JFrank]

I try not to let my match ammo sit outside getting too cold or too hot, unfortunately just sitting on the bench at -0- degrees or -10- the ammo will acclimate a bit and for whatever that’s worth.

Hunting ammo I torture test and cold bore hits are all I care about.

 

[Dave M.]

Dave, your post prior to your editing certainly took that path, my apologies for getting edgy, I’m somewhat sensitive to suggestions of untruth posts or lack of integrity.
Since I’ve joined I’ve learned a lot and thanked everyone here with my main goal to be truthful and respectful, secondly help anyone as I’ve been helped and show my work.
I’ve been pricked on here more than once for trying to help also had my name drug through the mud a couple times and I’m totally fed up with that crap. I just won’t take it any more.
Again my apologies.
Jim

No sweat Jim. Honestly I really don’t care about the temp sensitivity of N140 because currently I shoot RL-15 which is near the upper end (if not the top of the list) of the most temp sensitive powders. Also, the same exact load shot extremely well for me at both 28F and 48F and that’s what most important. Knowledge is power and I have a great thirst for knowledge and I also have a great deal of respect for the great shooters on this site that have helped me repeatedly over the years. I certainly appreciate your response and meant no harm in my reply to it. I’m an engineer and when I test something I take a very methodical approach and when the results are unexpected, I get very inquisitive and the first thing I want to know is whether others have seen similar results. Bless you and I truly appreciate your passionate reply. I too can get heated sometimes, especially if I thought someone was calling me a liar. I’m personally sorry again if I gave that impression, because it certainly wasn’t my intention.
Dave

 

[Dgd6mm]

Dave, Jim I learn from all of you. Especially in times like this.

 

[Dave M.]

Dave, Jim I learn from all of you. Especially in times like this.

This is a humbling enough sport as it is, none of us should have any energy to waste time on arguing.

 

[JFrank]

This is a humbling enough sport as it is, none of us should have any energy to waste on arguing.

We’re good , no worries.
I shot a ladder today at 500 yards so I’ll probably stay with H4895 for now.

 

[barefooter56]

I downloaded that same "temperature sensitivity" chart from somewhere online a while back, as well as a couple others that were similar. The real issue here is that we have no way of knowing exactly how the data in these temperature sensitivity charts were collected, tabulated, analyzed, etc. Even something as simple as case volume variance between different cartridges can affect these numbers. Further, the temperature response of a given powder is not necessarily perfectly linear across the range of temperatures we typically shoot. What that really means is that any expectations we may have about the thermal sensitivity of a given powder are totally based on information that may or may not be accurate. In the case of N140, it seems that the information in the chart was not accurate in the rifle setup and/or conditions used by the OP. Likewise, I have seen similar change in velocity per degree Fahrenheit values posted for Varget that were nowhere near those I routinely observe/measure.

VV POWDER does not have any " charts" like this on their powders due to their being more factors than just ambient temperature that can affect this.

 

[Dave M.]

VV POWDER does not have any " charts" like this on their powders due to their being more factors than just ambient temperature that can affect this.

No manufacturer has this info on their powders. Temp was basically the only parameter changed in my testing, and the velocity fluctuated far more than I expected.
Dave

 

[Bc'z]

No manufacturer has this info on their powders. Temp was basically the only parameter changed in my testing, and the velocity fluctuated far more than I expected.
Dave

Despite fluctuations in V, did the load still shoot well?
I ask because I'm running N140 as well and have yet to not see it shoot over different temp and humidity swings,
Summer and winter.

 

[Mulligan]

Despite fluctuations in V, did the load still shoot well?
I ask because I'm running N140 as well and have yet to not see it shoot over different temp and humidity swings,
Summer and winter.

Exactly what I’ve seen.

CW

 

[Dave M.]

Despite fluctuations in V, did the load still shoot well?
I ask because I'm running N140 as well and have yet to not see it shoot over different temp and humidity swings,
Summer and winter.

Both shot fantastic. In fact, so well that I have decided to shoot it in this barrel for my newest 6 dasher. I’ll see how it does compared to my previous barrels on this gun which have all shot RL-15.

 

[JFrank]

Despite fluctuations in V, did the load still shoot well?
I ask because I'm running N140 as well and have yet to not see it shoot over different temp and humidity swings,
Summer and winter.

Just butting in, you know I didn’t see the radical swings in V vs T and the load shoots pretty decent considering I didn’t test with different primers or bushings rather just looked at one for one against H4895.