Home Forums Hunting & Shooting Ask The Gunwriters Varget Temp Sensitivity Article...

Someone posted a link to a Varget Temp Sensitivity article here a year or so back... was a fairly technical article and a good read... anyone have that link?

Thanks

Not sure if it was an article, but Denton has done some extensive work on that topic. Perhaps a PM to him would reveal all.

I've seen Denton's excellent article, but that's not the one I had in mind...

http://www.shootingsoftware.com/ftp/Pressure%20Factors.pdf

I only used one rifle and one caliber for actual testing but had a hunting load for a 308 that was loaded with Varget and only saw 28fps average variation between 94 degrees F cold barrel shooting and 26 degrees F cold barrel shooting.

My old load with Rx 15 produced 73 fps variation and a load we had with W748 produced 124 fps variation all with the same conditions.

Far from a scientific experiment but I've been using Varget since the first year it came out and almost always shoot through a chronograph at the range and have had similar results ever since.

Almost all my rifles shoot nothing but Varget and velocities seem to be very stable through temp changes and with different cartridges.

Velocity is always excellent and accuracy seems to usually be very good.

From 223 Remington to 300SAUM plus in my 375H&H, Varget is my number one choice and I've never had reason to doubt it or change...

$bob$

That's pretty much exactly what I've seen with both powders.

Yep... I will admit that Rx15 produced slightly better velocity and accuracy was slightly better in moderate temperatures though. I had used Rx15 for quite a few years and must say it's a hell of a powder...

$bob$

Yeah, it typically igves higher velocities during summer range work and in some rifles is more accurate. BUT, if accuaracy is equal with Varget, I'll take the more consistent Varget over RL15.

73 FPS variation from RL15 over a 50 degree temperature swing? Did I read that right?

That's about exactly what I've seen...

Yup

$bob$

I'll save you the drama Brad...

Stick with 165 Partitions and Varget and you'll not likely see any shift in impacts between now and middle summer. I've chronographed that load from -18 (as cold as the Chrony display will work) up to mid 90's It's in the 2710's in the dead of winter, and in the 2730's in the summer

Also, the difference in speed between 45.5 and 46.0 grains ain't worth the extra wear and tear on your brass... Bumping up that last half grain only netted me 20 FPS in the Montucky, worse accuracy, and bigger spreads. 45.3-45.4 is where it noded up in my Montucky, at a year 'round avg of 2720 FPS, and pretty much groups under 3/4" in any conditions that aren't completely insane...

I wouldn't sweat it. Most stable powder I"ve used. WIsh they all were.... very low variations from 20s to 100s... and I did a group test a few times where in the low 100s in the shade we shot a 10 shot group, then shot another each time leaving the next round in the chamber 30 seconds longer. Group was almost identical, and impact location was identical.

If this is your question, you have too much time to spend on the internet and not enough time to shoot

So, what does a 73 fps variation equate to in differences in point of impact at various distances?

Dan, my last 308 (22") went 2,720 with 45.0 gr's Varget.

My current 308 (22") requires 46.0 gr's Varget (same lot as above) to get 2,720.

I've not shot enough Varget vs. RL15 to be adamant about it in this rifle, but so far the accuracy edge seems to go to RL15.

Hey, thanks for the input!

You obviously don't hunt at -30F and do your load development in the summer in the 90's.

But I'm not a fat old man that sits on the internet with nothing better to do than snipe at people they've never met and know nothing about, and on topics out of their depth...

Cake eater...

Dober

Well yeah!

Did you ever try TAC? I have 130's TTSX bullets flying nice with 47 grains of TAC in my Montana, deer are the intended target.

I load all my hunting ammo at about 60-65 degree's,the max I will see here where I hunt.I have tested RL-7/RL-10X/Varget/H-4198/H-322/H-110 and Benchmark at roughly 65 degree's and at around 25-30 degree's and can't see any appreciable difference in any of them..Yes,they all loose velocity but toss a coin which is worst that would make any difference in point of aim.

Extremes are not all that extreme.

Man..A guy has to do all this stuff himself or you will never know how it works..Gotta see it with your own eyes and theres no one to blame but yourself!!!!

Jayco