Varget and temperature sensitivity.

[jlow]

Thinking of switching to Varget because it is suppose to be relatively temperature insensitive and it can get very cold in winter and hot in summer here in Michigan. Hodgdon in their website here:

http://www.hodgdon.com/smokeless/extreme/page3.php#top

States that for 308 Win, using W-W case, WLR primer, and 168 SMK, extreme velocity from spread (I image 0 degree F to 125 degree F) to be 8 fps.

So if I input similar data into QuickLoad for say 43 grains of Varget, at 0 degree F, MV is 2414 fps. For 122 degree F, MV is 2565 fps so a change of 151 fps. So in essence the two says two opposite things.

My question to the experts on the board is what is your experience? Not out to slam either source, just trying to figure out which is more accurate so I can make a decision, and yes I do have Varget!

 

[CatShooter]

Thinking of switching to Varget because it is suppose to be relatively temperature insensitive and it can get very cold in winter and hot in summer here in Michigan. Hodgdon in their website here:

http://www.hodgdon.com/smokeless/extreme/page3.php#top

States that for 308 Win, using W-W case, WLR primer, and 168 SMK, extreme velocity from spread (I image 0 degree F to 125 degree F) to be 8 fps.

So if I input similar data into QuickLoad for say 43 grains of Varget, at 0 degree F, MV is 2414 fps. For 122 degree F, MV is 2565 fps so a change of 151 fps. So in essence the two says two opposite things.

My question to the experts on the board is what is your experience? Not out to slam either source, just trying to figure out which is more accurate so I can make a decision, and yes I do have Varget!

Software is just that, software... it gives estimates. It does not know a lot.

Varget has an excellent reputation for temperature stability.

 

[jlow]

As clearly stated, my question it is not which is right but what has been your actual experience. That is the only thing I am interested in here.

 

[Mr. Ten-X]

Best thermal stability of any powder in its burn range...and that is my experience ever since it was available to the consumer market in early 1995.

When it first became available, I tested it in an AR15 and a Palma rifle at 600yds in low 60's temps. After firing a shot across the chrono every 30 seconds for a 10-shot group, an 11th round was allowed to cook in the chamber for 60 seconds. In both calibers, the 11th shot went into the elevation of the prior 10 shots and the velocity of the 11th shot went into the extreme spread of the prior 10 shots. Loads developed on that day held through range temperatures of 100F in full sun using the same lot of powder.

 

[jlow]

Thanks! It’s the ES caused by the change in temperature that I am worried about and trying to avoid. Do you remember how much faster it was?

 

[Mr. Ten-X]

I cannot say because my annual testing was always done on the first day in spring when it would hit at least 60F. I have NO specific data that addressed ES at a variety of temperatures..

This much I will say. If I was in a team match in June, July or August and had to lay on the gun for my coach (in any temp), I did not have to open the bolt or change the round. If I did my job, the shot could be called within a ring or slightly outside on the LR target. Temperature just did not seem to affect grouping when I was shooting at 30+ degrees higher than the testing temp.

 

[jlow]

Thanks! I for some reason missed the fact that you were shooting at 600 yards… If heating the round in the chamber did not significantly change elevation or grouping that pretty much clinches it….

 

[jlow]

BTW, that’s a good tip you gave me about leaving the round in the hot chamber to heat it up. I was always aware of this as a potential problem but never as a way to test a powder at elevated temps. I might actually give it a go with some mildly loaded stuff with Varget and my other powders to see what it does.

As a background to why I am doing this – I live in Michigan and its pretty cold here this year ~10-20F but want to continue to do load development on days when it gets up to mid 30s which is where I draw the line. The problem comes when powder is temp sensitive and potentially affects MV and location of the accuracy node. So the battle goes on….

Anyone else fighting this battle is welcome to pipe in.

 

[Keith Glasscock]

If you read the QL instructions, it says NOT to use the temperature function with Hodgdon's extreme powders (Varget is one of them).

As for temp stability, I've been testing Varget in the 308 for a long time. It does, indeed, keep the velocity pretty steady winter to summer. The only thing not accounted for in the powder is the changes to bore dimensions due to differing environmental temperatures.

In my new Dasher, the velocity from 20 to 60 deg F varied a whopping 1 fps on the average.

Hope this helps

 

[bigedp51]

jlow

Remington/DuPont setup the powder plants in Australia which is now ADI and sells powder to Hogdon's. The Australian military requested ADI to make their powders more temperature stable for use at home and abroad. These powders are all single base powders and extremely temperature stable as required by the Australian military.

In Iraq and Afghanistan our military had to switch from double base powders to single base powder for their long range sniper ammunition. The special long range 7.62 ammunition was changed from RL-15 to IMR-4064 powder due to temperature problems with RL-15.

If you want to know how stable ADI powders are ask the Australians, they have some of the most extreme temperatures on our planet.

 

[M14AMU]

No No NO! Varget isn't worth a damn!! You guys stay with something like hmmmm....IMR4064!

Leave Varget be!!

Terrible!!

 

[CatShooter]

No No NO! Varget isn't worth a damn!! You guys stay with something like hmmmm....IMR4064!

Leave Varget be!!

Terrible!!

What he said...

 

[boltgunluvr]

Varget and IMR 4064 are "go to" powders for 308 & 223! 4064 gives me better accuracy. It's given me slightly better lot to lot consistency. Overall...flip a coin and shoot whichever is on the bench.

 

[Mr. Ten-X]

When Varget hit the consumer market in '95, VVO also intro'd their 500 series powders at the very same time, though the 500's were far harder to acquire. I was able to get a 2# bottle of the N540 and tested it on the same day, using the exact same rifles and did the same 11 rd test The booolits were the SIE155MK in the Palma rifle and the JLK80 VLD in the AR15.

The 11th shot in the Palma rifle went 50fps faster than the mean velocity of the prior 10. It gave me a tall shot that was def unacceptable.

The 11th shot in the AR15 was 80fps faster than the mean velocity of the prior 10. That shot was total fugly.

The little benefit in velocity of the N540 over the Varget was worthless for my purposes.

 

[Mr. Ten-X]

Another note on Varget would have to be the wide spread of performance between lots from '95-'03. If you took a std 13" twist Krieger @ 30" Lg with .3075" bore having a WTC95 chamber and the lightweight WW cases (157gr) of that timeframe as a benchmark, 45.8gr was a very normal charge weight to hit 2950fps As time progressed through 01-02, guys were using up to as much as 46.5gr of Varget in the far heavier LAPUA cases to hit that 2950fps velocity and many were even using the bullet-squashing 298/3065 bores. As God is my witness, some folks whom I trusted (mostly) were even using as much as 47.0 grains. There was a steady progression towards softer pressures with Varget over time. Every new 16# case had to be re-tested (if you were smart and followed standard reloading procedure) to hit that 2950fps range, give or take.

Then the 01-02 powder lots that was being bottled for the consumer market suddenly went back to the performance characteristics of those original lots from 1995. You can only imagine what happened to the folks that didn't bother to test these new lots, choosing to just be complacent with their present loads. Lots of sticky bolts, blown or smokey primers, etched bolt faces and ruined cases.

The thing is, the powder was STILL within the Hodgdon tolerance for pressure variation, per Chris Hodgdon. The moral of the story is pure common-sense reloading procedure: Always back off your charge weight and re-test when switching powder lots.

Even with those pressure changes in lot variation over time, I could never point to changes in the performance from lot to lot in hot temps when the powder was initially tested at my std 60 degrees. It was always about the lot change, not temperature.

 

[johara1]

jlow, My experience with Varget is limited to the 6.5x47 and the Dasher None was good, temp. sensitivity is only one factor, but lot to lot swings is an other To get to the velocity where it shot with one lot, the next lot may not make the velocity because of pressure. The next lot may make the velocity but not shoot. It does fire form my Dasher cases good though…… jim

 

[Terry]

Jim

I use the Al Forbs powder lot method. As AL taught me I mix all the varied lots into one. Now I have the same lot in all my powder.
Of course I make sure to blend them thoroughly.

Another great lesson Al taught me was to be patient on the shooting line.

Thanks to Al!

 

[jlow]

If you read the QL instructions, it says NOT to use the temperature function with Hodgdon's extreme powders (Varget is one of them).

As for temp stability, I've been testing Varget in the 308 for a long time. It does, indeed, keep the velocity pretty steady winter to summer. The only thing not accounted for in the powder is the changes to bore dimensions due to differing environmental temperatures.

In my new Dasher, the velocity from 20 to 60 deg F varied a whopping 1 fps on the average.

Hope this helps

Thanks! I did not see that comment in QL. I've tried using both "Hodgdon" and "extreme" in the PDF search function and did not find that comment - do you know which page tha is on?

 

[jlow]

No No NO! Varget isn't worth a damn!! You guys stay with something like hmmmm....IMR4064!

Leave Varget be!!

Terrible!!

What he said...

Sounds like somebody is trying to keep all the Varget for themselves...LOL! Too late...

 

[jlow]

jlow, My experience with Varget is limited to the 6.5x47 and the Dasher None was good, temp. sensitivity is only one factor, but lot to lot swings is an other To get to the velocity where it shot with one lot, the next lot may not make the velocity because of pressure. The next lot may make the velocity but not shoot. It does fire form my Dasher cases good though…… jim

Thanks! I've got enough of a single lot for a few years.