Re: RL15 vs Varget
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jr81452</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Falar</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: USMCj</div><div class="ubbcode-body">The one think you will learn about Vargay if you use a lot of it is that it varries lot to lot way more than any other powder. RL15 on the other hand, not so much. I dropped Varget a long time ago in favor of RL15. There is nothing Vargay can do that RL15 cant. </div></div>
Actually there is.
RL15, like the entire RL series of powders, is highly temperature sensitive.
Varget, like all of the Hodgdon Extreme powders, is extremely insensitive to temperature changes.
</div></div>
Why do people always say that? When I used varget to work up some hunting loads in '08, I worked them up here in FL two weeks before I went to MN for my hunt. When I got to my cabin I re-zeroed my rifle as is prudent. Well what do you know, the 50deg temp variation caused a 3.65" drop in my POI @400yrd. Even after the change in elevation from sea level to +1864. Granted, with RL-15 I get a 4.87" drop in POI under the same conditions, but either way you need to re-zero. I suspect that those who claim varget is not temp sensitive, don't really test the theory. </div></div>
I have. Not RL-15 specifically, but nothing I have ever tested from Alliant was even close to as temperature stable as Hodgdon Extreme powders.
X axis it in degrees F. And yes, I did heat them that high.
Here is my test method (copied from another thread):
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">What people notice based on air temperature isn't the best indicator of temperature sensitivity. Rounds brought from home in a plastic case, transported in a heated/cooled vehicle will often experience very little change in temperature internally. Unless the rounds are soaked in an exposed manner, at temperature, for at least two hours, you don't really know the powder is at that temperate. The first time I ran this type of test, I put a thermocouple inside a loaded round (without primer) through the primer hole to see how long it took for the internal temperature to be the same as external.
The way the tests works is that you soak 3 batches of ammo at hot, cold and ambient temperature for at least two hours (5 rounds of each). I use a cooler with a heating pad for hot, the freezer in the clubhouse for cold (an icebox works too), and just sit the rounds out in the open for ambient. Temperature is measured with thermocouples and/or mercury thermometers.
You then fire them one round at a time in a round robin sequence (ambient, hot, cold, ambient, hot, cold...). You let the barrel cool in between each shot. When you fire each round, you just transfer that round from the hot/room/cold storage to the chamber and fire it through the chrono as quickly as possible. You don't want to give the rounds any time to change temperature internally due to contact with the chamber. I set the scope on the lowest magnification and just make sure I'm sending the round through the sweet spot of the chrono (no groups here). You basically want to the Jerry Miculek of loading a boltgun and firing it through the chrono. This is best done on a short pistol range, close to the berm.
If you're interested in the powder's temperature sensitivity, you don't soak the entire rifle, that isn't scientifically correct because you're mixing multiple effects. Thermal expansion/contraction of the barrel due to temperature is a different effect than powder temperature sensitivity. In this test, we are only interested in the powder's effect (primer too, as it cannot be isolated). By using the round robin sequence and letting the barrel cool in between shots, you are removing its temperature effect as a variable in the test. If you then wanted to take it to the level of testing it as a system, you would know how much the powder is contributing. Otherwise, you cannot isolate it from the barrel's effect. Then, you don't know how much each is contributing to the problem.
It isn't a difficult test to run. However, if you don't have the ability to measure pressure (I do), I would advise putting the heating pad on a lower setting. </div></div>
If you've performed similar a test of RL-15 vs. Varget, then by all mean, post the results and test method. I find it hard to believe that RL-15 is anywhere close to as temperature stable as Varget given that its double based.
