Temperature sensitivity

[FishfinderAK]

I brand new to reloading. But I keep hearing how Varget is so insensitive to temp changes.
Is this really a major concern w other powders?
Living in PNW I suppose I should take heed, but have heard of anyone use Varget in 300 WM.
Thanks

 

[Cahunter805]

Many powders are temp sensitive and many aren’t. For your 300win I would start with H1000.

 

[packer58]

300 WM favors the the slower burning powders, Hodgdon has a full line of "EXTREME" powders that are temp stable. With a little research you"ll find lots of proven load data using these powders.

 

[elkguide]

In my .300 Win Mags I shoot.....

IMR 4350
RL 22
H 4831SC
H 1000

 

[N2TRKYS]

ALL powders are temp sensitive. Some moreso than others. And some are affected more in certain cartridges. I don't shoot in the summer, cause it's hot as balls in the summer here. I only work up loads during my normal hunting temps. Temp sensitive hasn't been an issue for me.

 

[Kraze]

I agree with the others for starting with H1000 for your Win Mag. And yes, all powders will be temp sensitive to a point. You won't want to work up a max load with a temp sensitive powder in the dead of winter then try shooting that same load in Death Valley in the middle of summer, for example.

Here's an article with some testing of powder temperature sensitivity (Varget is one of the powders): Powder Temp Stability: Hodgdon Extreme vs. IMR Enduron - PrecisionRifleBlog.com

 

[carter33]

I have reloaded for .300 WM in the past and actually just got a new .300 winmag in that I have loaded some rounds to test out today using H1000 with both 210 Berger VLD and Nosler 210 accubond LR. I live up in Fairbanks and it will likely be negative temps when I first take velocity readings, I will take them again using the same load in summer to have an accurate velocity as well as note the change/sensitivity as I have been seeing more info come out recently about one powders sensitivity relative to another. May even load another powder to see the differences, have some extra time to kill over christmas.

The temperature of the powder absolutely does effect muzzle velocity (as others have said) in the way one would logically think. The warmer the powder the higher the velocity. That being said unless thier is a drastic difference in temp the slight change in MV is unlikely to to change your POI enough to account for it at standard hunting distances.

 

[N2TRKYS]

I love me some RL16 and RL26. I’ve noticed a slight increase in velocity with RL26 when it got colder than when I worked up the load.

 

[dog]

It can be an issue but more so for match shooters than hunters. I used to use 4064 in my .308 but found my loads that were worked up during the warmer months did not group very well in the cool of November right before hunting season. (it still grouped good enough to kill any deer at any distance I was likely to shoot) But still, I didn't like that so ended up switching to Varget and haven't had that issue since.

 

[mcseal2]

I use H1000 in my 300 win mag with 180gr Accubonds. For my moose hunt I tried a box of Nosler factory 180gr E tip ammo I found on sale, figured the tougher bullet wouldn't hurt anything. It is 50fps slower but equals or maybe even edges out my handload for accuracy. Between the two loads I should be ready for anything a 300 will work for. The E tips both exited my moose broadside at 300yds and he went only 30 yards. I actually stopped one in my whitetail I shot quartering to me at 370 yards and it looked like it performed well. It weighs 179gr.

 

[RosinBag]

You can test any powder for temperature sensitivity. Load up six rounds and put three in the refrigerator overnight and the other three put on the floorboard with the heater on...shoot all six through the chrono and you will no how your powder does.

Vhitavouri, H1000 and Retumbo have all done well for me.

 

[Swampr42]

H1000 is a great powder. H1000 and 180gr Accubonds is my go to combo in my 300wm. I see really no change in velocity during the four seasons we have here in SW Washington.

 

[roadrunner]

IMR 4350 is supposed to be temp sensitive, but I've never seen it.

Use it almost exclusively.