Powder suggestions

[the86d]

Varget is cut about half the length of the average 4064 granule. A third the length of the longer 4064 granules.

Thank you. I was actually wondering about some of the differences.

Since you mentioned it, I do recall Varget (my first rifle powder) having shorter granules...

[middleofnowhere]

What do you guys think if the barrel is short, say 20”?

[sigguy552]

Get an autotrickler and all your metering issues pretty much go away. I drop a charge in seconds and it’s accurate to about 0.01 which is overkill since each kernel of 4064 is 0.02.

[ar15barrels]

I would like the temperature stability because the temps we live in.
The high is mid 90’s, which is not an issue. But the lows range in the low teens, occasionally colder.

ALL powders have variation with temperature.
When you hear about certain powders being more temp stable, they just are supposed to have less variation.
The difference is actually smaller than you would think when you actually look at real numbers.

For example, lets use Quickload to compare some different powders.

Test conditions:
308 Winchester, 24" barrel, 168gr Sierra Matchking seated to 2.800" overall length
Loads for comparison chosen to stay between 59,000psi and 62,000psi at 110f degrees so none of them will go over-pressure at 110f.
Temp - 45gr Varget - 46gr TAC - 45gr 748 - 46.5gr BL-C2 - 43gr 8208XBR
110f -2769fps - 2745fps - 2798fps - 2785fps - 2744fps
70f - 2724fps - 2700fps - 2756fps - 2738fps - 2707fps
30f - 2675fps - 2648fps - 2709fps - 2685fps - 2663fps

Here are the resulting 80 degree temperature swings:
30~110 - 94fps - 97fps - 89fps - 100fps - 81fps

I don't personally like shooting below 30 degrees, but if you are a polar cat, here are the subzero numbers and the subsequent full 120 degree velocity swing:
-10f - 2623fps - 2595fps - 2656fps - 2629fps - 2618fps
-10~110 - 146fps - 150fps - 142fps - 156fps - 126fps

Different temperature ranges or loads could make the numbers very different.
The closer you are to max load, the larger the temperature delta will be.

Don't worry about powder temp sensitivity.
Just go with the powder that your gun shoots the best and chrono your load in hot and cold weather so you know what to expect.
If you do enough actual testing, you will find that you need different loads in different weather to get the best accuracy anyways.
No powders are actually temperature insensitive enough to matter over your 80 degree stated temperature range so just forget about it and be more concerned with the actual load that your rifle prefers.