Which of these powders is the LESS temperature sensitive?? Varget or RL 15?
I would assume it is Varget: Varget is an "Extreme" and as far as I know those are all ADI single-base powders. Re15 is a double based powder, though I don't know how much nitroglycerin it contains in comparison to powders like H335 and W296. I think it's pretty much accepted as common knowledge that double based powders react to temperature change more than single based powders.
RiverRider,
Dunno about "common knowledge," but many double-based powders introduced in the past 15 years or so are as temp-resistant as single-based powders.
If ya want a 'Temp Insensitive' RL 15, and want to use an Alliant Powder, then try AR Comp.
No quit the same burn rate, but awfully close in the real world situations in the field.
MD, I know that's right. I've found myself speaking from the past before, and here I've done it again. Twenty years just doesn't seem like a long time anymore.
MD, I know that's right. I've found myself speaking from the past before, and here I've done it again. Twenty years just doesn't seem like a long time anymore.
Ain't that the truth...
20 years ago seems like yesterday anymore.
Mule Deer, are you saying that RL15 is more temp stable than Varget??
I can only state what has been my experience. I do most of my hand load work up in Tucson's hot summers. I figure pressure problems should show up a bit quicker in the heat. My hunts the last seven or so years have been for elk in the Raton New Mexico area, the Vermejo Park ranch to be exact for cow elk. I usually hit the Whiiting range to check my sights the day before the hunt. Rifles tested have been .270 Win., .280 Rem., 30-06, .300 Win. Mag. and .35 Whelen.
The .270, .280 Rem., and .300 Win. Mag. were charged with Winchester Magnum Rifle Powder (WMR). The 30-06 with W70 and the .35 Whelen with Re15.
Loads were worked up at temps ranging from 95* to 115* Won't forget that day.) Temps at the Whittington range ran from 28* to 68 above. Points of impact for all loads were unchanged, even at +6*. Both W760 and WMR were reputed to be very temp sensitive. Brass in all loads was Winchester except for the Whelen which used Remington brass. Primers were standard Winchester WLR. No magnum primers used. Dunno if this proves anythong or nothing, just what I experienced with the above mentioned powders. YMMV.
Paul B.
Varget is about 10 times less temp sensitive than RL-15 according to Hodgdon's tests.
While that is a big difference, it's not necessarily a problem for the average user.
In other words, temp sensitivity isn't an issue until it is.
When the military was looking to solve real problems with their existing long range designated marksman ammo caused by RL-15 under actual combat conditions, RL-15 was found to be much too temp sensitive to pass their tests and get the job done, and it wasn't a close call.
Shooting 100 yard groups at the range, probably not, but when the success of the mission is at stake and lives are hanging in the balance, then it matters.
DLALLDER,
No, I was NOT saying that RL-15 is more temp-resistant than Varget. I was replying to RiverRivers' post, where he said it's common knowledge that single-based powders are more temp-resistant than double-based powders--which he later retracted. I said, "many double-based powders introduced in the past 15 years or so are as temp-resistant as single-based powders," and RL-15 was NOT introduced in the past 15 years.
In my Whelen and 350 rem mag I've been using TAC with good speed and accuracy. Where would you put TAC in the range of temp sensitive?
In my tests it's been very temp-stable, but any of them can vary some in different cartridges.
In my tests it's been very temp-stable, but any of them can vary some in different cartridges.
True statement. In the 338 Fed I have seen TAC lose around 100 FPS (70 to ~18deg). Basically it acts like a typical ball powder. 8208 is a similar powder that loses very little in the cold, in this cartridge.
Yep, which is why anybody really interested in how their loads perform at different temperatures should test them, in their rifles.
TAC was originally a military powder, designed primarily for the 5.56x45 NATO, and secondarily for the 7.62x51 NATO-which is why it works very well in the .223 Remington and .308 Winchester. The first cold-test I performed with any Ramshot powder was with TAC in the .223 with 50-grain Ballistic Tips, and it got exactly the same velocity at zero degrees as it did at 70. But temp-resistant powders can lose some of that characteristic if used outside their "comfort zone."
The opposite is also true. Many powders not considered temp-resistant can do pretty well in certain applications, but we won't know if we don't test 'em.
So now we need to talk about the powders' "comfort zone"...sounds like a teenager thing!
Well, many temp-resistant powders ARE teen-agers--or even younger!