Has anyone switched from RL 15 to Varget because Varget is supposedly more temp in-sensitive??

Zephyr, Just curious, are you having problems with RL15 ? I have been loading RL15 in a 450-400 and have shot the rifle on days below freezing to days well over 100. Rifle always goes bang and hits what I'm aiming at if I don't jerk the bloody trigger. I guess my point is if RL15 is working for your 416, why mess with success ?

Perhaps being lured by the advertising of small pressure changes in large temp swings. Here in Vermont our summer days are in the high 70s low 80s I'm off to Zim in Sep with the temps in the 90s..

I keep hearing about how great Varget is but I have never used it---just RL15. I also use RL15 in my 416 Rem. In my 470NE I chronoed the loads in 50 degree temp up to 90 degrees and the velocity went from 2060 to 2200fps with the 500gr Woodleighs.

My interest would be in changing if Varget is more consistent from lot to lot. Not only is RL15 temperature sensitive but also varies from lot to lot. This variance can be up to several grains in weight to get the same velocities. Does Varget vary like this from lot to lot?

Barsness claims that RL 15 has been a temp sensitive(extreme) powder from the beginning.

I use Varget in my .416 Remington. It works just fine. 350 gr Barnes tsx and Varget produces very small groups out of my Remington.

Powders in the medium burning range such as Varget and RL-15 tend to be relatively insensitive to temperature changes. That is one reason why the militaries of the world use them. That said, Varget is the least sensitive of the lot.

In the 1990s Remington factory loads, especially the round nosed Barnes homogeneous bronze solid loading, contained a powder that was consistent in its looks with RL-15. I had some of that ammunition. the powder charge was very compressed; it formed one big lump. When I torched off a few rounds on a 115 degree f day in Idaho, I had sticky bolt lift, difficulty extracting the casing and a split neck in one instance.

Part of the problem is that RL-15 can, and often does vary in its burning speed by up to 5% between lots.

Another part of the problem is trying to reach 2,400 fps with a big monolithic metal bullet; there just is not enough room in there.

RL-15 can be employed safely, and without high pressure excursions in hot weather by some or all of the adjustments.

1. If using a homogeneous/monolithic solid, choose something like the North Fork at 380-grains. That leaves more space for the powder.

2. Back off your top loads by 2-3 grains. You will still have plenty of velocity and power to get the job done.

3. Consider using a Woodleigh steel encased solid bullet. Those work just fine, and leave plenty of room for the powder.

I have used both RL-15 and Varget in a rifle chambered in 416 Remington magnum. Both worked wonderfully. Accuracy was phenomenal, and velocity was spot on. IIRC my top load of RL-15 with a 350 grain Swift A-Frame was 81 grains. My max with the 400 grain A Frame was 76 to 78-grains, depending on the lot I was using.

I just used 2,350 fps as a target velocity; usually ended up at 2,370 fps, and had zero problems. 2,550 is a sensible maximum for the 350 grain A-Frame bullet.

I just followed the Hodgdon annual manual to work up a Varget load. Both powders do a great job. I use RL-15 most of the time because it meters more easily than Varget (i.e. within .1-grain versus being within .2-grains).

I will be pressure testing various loads later this year. Several years ago, I posted some pictures of what I dug out of the factory loads; it was pretty impressive. Someone got greedy for velocity. A similar thing has occurred in the past with factory 458 Win Mag ammunition.

If you have any further questions, feel free to shoot me a PM.

The same charge of AA 4064 propels either a Hornady 400 RN or a Nosler Partition 400 at the same 2400 fps and to the same point of impact for me. I realize that neither of these is a solid, so the AA 4064 may act differently with such a bullet.

AA 4064 is a bit slower than the IMR variety, thus seems a good match for the .416 Rem. As to temperature, it seems like its always in the 90's in Texas, so that's the temperature my loads are adjusted to. The concept of "temperature insensitivity" is significantly more prevalent in the marketing division than among the ballisticians of a certain large powder repackager in Kansas.