AA#5 Temp Concerns

[627PCFan]

I have switched to using AA#5 in my 125gn 357 self defense loads, which typically stay stored in my car during the summer. I know AA#5 is close to Bluedot on the burn rate chart and Bluedot has the temperature senstitity problem when it comes to heat. Is that a common problem with powders in that burn rate zone, or is it just specific to the blue dot powder formulation?

 

[Walkalong]

You will see velocity/pressure increase with it in high temps vs low. Work up your load in the heat.

 

[jstein650]

Agree with ^ Walkalong. I've used quite a bit of both, and prefer B-Dot. AA#5, for some reason is just one of those powders that I've really gotten apparent pressure spikes with. It does seem more temp. sensitive, plus if you're loading near max., it doesn't take much to get a really hot load. I noticed this mostly in .38 spcl.

 

[Steve C]

AA5 is much more like Unique while AA7 is more like Blue Dot. Similarity in burn rate is not the functional cause of a powders reaction to heat or cold which is a characteristic a the particular powders formulation.

Blue Dots temperature issues where always with very cold temperatures and not hot ones. I've loaded .357 mag with 13.8grs of Blue Dot behind a 125gr JHP for over 35 years now, have shot and carried this ammo in my automobiles in the hot (really HOT) Arizona desert for 29 of those years without any problem. When chrono'd this load is a ballistic duplicate of the full power factory at 1,450 fps from 4" barrels +/- reasonable differences between different pistols. Never had any pressure signs that gave me a second thought.

There is no "rule" on how all powders perform in warmer temp's but in general they are more consistent and ammo has bit higher in velocity due to the air being thinner, not the powder increasing its pressure. There are only a few well known issues with temperature sensitive powders most of which are rifle powders that are of any concern and these only show up with loads at the top end of the load range. Usually temperature sensitivity shows up in a change in the ammo's accuracy. Your not going to "blow up" your gun if you are using a load worked up from any current manuals data.

 

[627PCFan]

That makes me feel a little better. Im shooting a mid range load that happens to be the most accurate, not pushing the envelope. Appreciate it-

 

[BullfrogKen]

What Steve said.

AA #5 is not much like Blue Dot at all. And #5 does spike dangerously when you try to make it pretend to be a magnum pistol powder - which it's not. I use #5 a lot - 9mms, 40 S&W, 38 Special, 45 ACP, mild 45 Colts and mild 38 Supers. I've never put any in a 357 magnum case, or pushed it beyond +P 38 Special velocities.

I have used Blue Dot for .357 magnum loads and been quite happy.

I've only heard about Blue Dot performing poorly in extreme cold conditions. But it doesn't seem to care about how hot it gets.

 

[ljnowell]

AA5 is no more "spikey" than other powders in a similar burn rate zone. Any powders of that speed will not work well when being loaded to near-magnum velocity. They arent intended for that. Load it for what it is and select a different powder if you desire more oooompf.

 

[ArchAngelCD]

I also have not tried to make AA#5 into a magnum powder but I do use HS-6 for middle to middle hot .357 Magnum loads. (now that W571/HS-7 is no longer available) I do really like AA#5 for building Speer 135gr .38 Special +P replica ammo. It works extremely well in that application and can be used for .45 Auto ammo, especially since it was designed around the .45 Auto.

Unlike in the past there are MANY good powders for loading all ranges of cartridges. Every company has a powder that will fill a niche and one company's powder in that burn range will mimic the other company's powder in the same range. If you pick a company and use their powders I'm sure you will produce ammo equal to another reloader who picks another company and uses their powders. There are many crossovers in reloading powder these days. Just look at Unique and Universal, both do almost the exact same thing but from a different company.