Low-flash & temp insensitive powders

OK, I'm relatively new here and possess rudimentary searching skills in forums, so I seek your collective help.

I'm looking for powders for both handgun and rifle (bolt and AR) that are stable, present low flash and are temperature insensitive. Long-term storage is also a secondary consideration.

Also, I have a question on primer shelf life. I have read that they are very stable, assuming cool and dry storage. I have several thousand hoarded during the primer panic in the 1980s that I have stored in my basement reloading area. It is cool, but humidity (Michigan) varies. I try to control it with a dehumidifier, but with inconsistent results. Should these be relegated to plinking loads or are they still OK for all uses?

I'm sure this has likely been addressed here before, so hyperlinks to threads are appreciated.

the primers are fine.
as long as they see relatively consistent temperatures,and aren't stored soaking wet they'll last for years.
the problem is nobody has stored modern primers for 50-60 years yet.
but the old ones have done fine so-far stored under decent conditions.

the best powder i know of for low flash handgun rounds was al-5 but it hasn't been made for @ 20 years. i am down to about 2.5 lbs of it.
the best way to avoid a big flash of light at the muzzle is to burn the powder inside the bbl.
something like rl-17 might do very well in a rifle as it burns faster as it goes improving your chances of it all being consumed before the muzzle.
usually this will call for a slightly fast powder for the muzzle velocity/accuracy you'll seek.
you'll most likely have to trade off one for the other.
and adding in the low muzzle flash will swing thngs towards the slow velocity side of the equasion.

Welcome to The Guide, Shotgun.

I don't shoot at night, except at varmints, so I don't pay much attention to night flash.

All powders are temperature sensitive.
The operative question is: how sensitive is any particular powder?

Never trust on a really hot day a load you worked up on a really cold one.

Watch any load on the hotter end of the charge table when the temperature is, too.

You will get lots of opinions about different powders, but the only way to be sure is to chrono your loads at different temperatures and see how the velocity varies as you do. No manufacturer is going to say "With Powder Q you will lose Xfps for every ten degree drop." If they did, they wouldn't sell much powder. Part of working up any load is testing it in temperature extremes, however extreme they can get where you live, and noting the results for future reference.

But some are more sensitive than others. The problem is that some of the most accurate rifle powders can lose several hundred FPS or more when temps drop from 80F to 10F, but the group sizes do not always change significantly. Point Of Impact shift is obviously greater as the ranges increase.

This is what I know: BDOT is VERY temp sensitive. (To the point where I have to keep my 10" .357mag Contender inside my coat when winter hunting if I want to hit anything with it.)

There is not enough difference in my IMR(3031, 4895, 4064) .308 deer rifle loads between 80F (workup) and 10-40F (actual hunting) that I have to adjust the sights for shots within 200yds, but still there is a significant velocity drop of at least 200fps between the extremes. If I hunted at longer ranges, it would matter. OTOH, I know for instance that my .22-250 IMR3031 varmint load will drop another 6-8" at 400yds when it gets down to -20F than it does at 85F. It is the only rifle I would likely use on both the hottest (woodchucks) and coldest (coyote) days of the year, and the only one I would use for really long shots, so I had to know how the load behaved when it got cold.

What is the difference between magnum primers and standard primers?
What is the difference between small pistol and large pistol primers?

The magnum primer burns hotter for a longer time(we're talking miliseconds here)
A small primer is just that...smaller in diameter than a large primer.In general,some cartridges use a large primer while others use a small primer.

some magnum primers burn hotter and some burn longer.
i suspect the small- large primer difference is being prompted by having 45 acp brass with both large and small primer pockets.
the 45 is truly a victim of circumstances here if the small pistol primer would have existed when the round was developed it would have used the small pistol primer.
it then was loaded and reloaded for 100 years with the large primer.
when all the sudden the factory's decided [prompted by pressure] they needed "green" ammo and the only primer suitable [available] was a small pistol primer.
so they redone some tooling and off they went.
making cases the way they would have been done origionally if the small primer would have been available then

...and some "regular" primers are hotter than "magnums" by other companies. I tend to stick with one brand unless I'm working on a "gun from hell" and can't seem to find anything that shoots decently in it.

Hodgdon is doing a lot talk about how they are getting their powders less and less temperature sensitive. I use a lot of hodgdon 4831 SC up here and we have extreme temp variation -40 to 100

Flash I never really thought a lot about!

Ken.