Is Alliant #9 too slow for 2" barrel OR do I have a powder moisture issue?

[7Acres]

I'm trying to troubleshoot the situation that occurred to me a couple weeks ago. I loaded up about 15 rounds of 125gr Boolits into .357 mag cases with Alliant #9. The 10 I fired with my lever gun all performed as expected. Of the 5 I fired from my S&W J640 only one seemed normal. One stuck in the barrel 2 stopped upon entering the rifling barely having left the brass. After pounding one of them back in enough to remove the round from the cylinder I pulled the boolit and dumped out the unburned powder. It was dark yellow and had a clumps of powder.

My other theory, and the one I think is more likely, is that I began my reloading session only minutes after pulling the powder and primers from the mini-fridge. Powder condensed moisture and didn't perform properly. But then why would every round in the lever gun shoot fine?

I'm about to learn a lot. Thanks in advance.

[454PB]

AA#9 is in the same slow burning class as H-110/WW296 and WC820, and can exhibit unpredictable ignition and burn characteristics if the charge weight or boolit weight is reduced too much.

You don't say what the charge weight was, but many years ago when I first started experimenting with 454 Casull, I used AA#9 with some 250 XTP jacketed bullets and found that nearly every round was a hangfire.

I now treat all the previously mentioned slow burning ball powders the same.......heavy boolits (or bullets), full powder charge weight, and magnum primers.

I've removed stuck boolits from several guns over the years, and only one was caused by a verified bad primer, the rest were a combination of light boolits and/or light powder charges. I found the same clumped up, yellow powder you described.

[7Acres]

Thanks for sharing that, 454pb! Yeah, I couldn't recall what the exact charge was. I used the Start Grains load for 125gr jacketed .357 magnum from the Lee Reloading Handbook. So yeah, it was a light boolit with a light charge.*

Is the slower burning #9 out of a revolver just not going to be reliable due to the fact that all pressure drops off as soon as the bullet leaves the brass (due to the small gap between the cylinder and barrel) leaving most of the powder unburned? Is this also why the lever gun had no trouble? Because upon firing the brass expanded sealing off the chamber and the powder charge stayed pressurized during the bullet's entire ride down the barrel properly burning up all the powder?

[snuffy]

Alliant does not make a #9 powder. Accurate Arms does.

As 454PB says, AA#9 is only slightly faster than H-110/WW296. it should be loaded with the heavier-for-caliber-boolits and at near max loads.

A better choice might be AA# 7 or even #5.

[454PB]

I've used these slow burners and heavier boolits in my S&W model 19 with a 2 1/2" barrel and have experienced no ignition problems. Up front I'll say there are better powders to use as snuffy said, but I don't think the fact that you were using AA#9 in that short barrel was the problem. I like faster burning powders with the snubbies. For the slow burners, good tight case fit, heavier boolits, and magnum primers are important.

[7Acres]

Snuffy, thanks for the correction on manufacturer. I've got some 158gr cast and lubed. I'll try loading those up with a near max load. I'd like to be able to use my supply of #9 as I don't have #7 or #5 at present. Thanks for the advise!

[cbrick]

454 is absolutely correct. All three of those ball powders need tight bullet tension & heavy for caliber bullet for reliable ignition. Your rifle may have been a help with tighter throat & no gap but odds are consistency & thus accuracy will improve with these powders using heavier bullets.

Rick

[rexherring]

Never have had a problem with AA#9 in my .45 Colt loads with 7 1/2 inch. Always used mag primers but get by with standard ones in a rifle. The weight of the boolit helps as does mag primers and tight crimp. Short barrel can leave a lot of unburnt powder any time you use slower powders. As a rule, I use faster powders with shorter barrels like unique, AA#2, Bullseye or HP38/W231.

[Shiloh]

I would think it would be to get the best performance. Have you clocked your loads?? I would think you are blowing a lot of powder out the muzzle.

Shiloh

[HangFireW8]

Slower powders usually mean larger charges for the same performance, larger charges mean more muzzle pressure. More muzzle pressure means more bullet destabilization outside the barrel and a less comfortable experience for the shooter.

Despite all that, slower powders (in heavier charges) are still the path to higher performance.

[Lloyd Smale]

like was said aa9 likes heavier for caliber bullets and good neck tension and a firm crimp and heavier loads. If your going to fool around with it for lighter bullets or lighters loads at least use a mag primer to light it off.

[44man]

I also say there is a lack of neck tension. It is NEEDED in revolvers.
If the charge was too low you have too much airspace and if the boolit moves out from primer pressure you increase the airspace even more. Powders like AA #9, H 110 and 296 can fail to light.
But even more important---why are you keeping powder and primers in a fridge? Take that stuff out of there and do NOT open the powder cans. Let it all get to room temp and keep it there.

[uscra112]

OK, I'm going to throw the cat among the pigeons here again. Some ASSRA guys are using #9 in large cases like .32-40, with pistol primers, in loads that are typically 35% density, to get 1400 fps from a Quickload-calculated pressure of 12K-13K psi. They choose #9 because under those conditions it gives the lowest velocity variance of any powder they have tried, and excellent accuracy in a discipline that considers 1MOA to be a decent starting point. I've duplicated these loads in my .25-21 Stevens, and I've proven this across my own Chrony, using fixed ammo with no crimp, (not breech seating - my little Stevens isn't throated for that). In my early workups for this load, I was down at about 30% load density and under 10K psi, and the loads were no less consistent.

This just doesn't support the notion that #9 needs heavy boolits, heavy crimps, and heavy loads to light off reliably. Something else must be going on if there's trouble in revolvers.

Running a bunch Quickload simulations using #9 in a .357 case, no matter the bullet weight, and no matter the charge, the models show the burn reaching peak pressure at about 1/2" travel of the bullet base. For a lot of revolvers, would be just about where the cylinder gap is, and that, given a mild load, might bleed off enough pressure to stop or slow the burn and give the O.P.'s results.

Just sayin', y'all........

[mpmarty]

Well I use AA9 in most of my 10mm loads and find it is the cleanest burning powder I've ever used. No mag primers and usually 175gr boolits in a 5" Tanfoglio pistol.

[44man]

It really is the revolver. Seen boolits driven a good ways into the bore with all the unburned powder behind it. The only cure is to INCREASE the powder charge.
Two worries with that happening, not seeing it and shooting another boolit or the thought of the powder igniting after the boolit stopped.

[ironhead7544]

Never had a problem downloading with #9. Used it in light 44 Spl loads with good accuracy. Sounds like it is just not burning. I would go up on the charge weight a little until this stops.

[10mmShooter]

as stated AA#9 is more for full max power loads, in my 686 I use #5, and even in my 10mm loads I use AA#7 for max loads, I only use AA#9 for my full throttle JHP load in 44mag.

[uscra112]

Playing with that Quickload model more this morning. Looking at peak pressure vs. bullet travel. Turns out that faster powders don't peak appreciably sooner. But in lighter loads they probably work better because they are more tolerant of the pressure drop at the cylinder gap. (Faster powders in general being happy at lower pressures than slow powders.) Soooo, we might want to conclude that any slow powder is a liability in a revolver, when using light loads. But that may be too broad a statement, since some slow powders may stay lit during that pressure drop, which AA#9 sometimes does not.

I need about $40,000 funding to build and instrument a test apparatus, and run a months worth of experiments. Surely the sequester isn't so draconian as to deny me that, is it?

[44man]

No matter what or where pressure peak is, I still believe powder continues to burn past peak if slower burning. It extends the curve and adds push past peak.
See unburned powder from short barrels? WHY?
Stop looking at the spike and see what is after.

[Cherokee]

I use AA9 in a 1250 fps 32-20 rifle load for 115 gr FN that is very accurate and consistent, fired by small pistol primers. Had one failure to ignite in many thousands of these fired in rifles and pistols. Pulled the bullet and the powder was a small black blob, considered it a loading error on my part since so many thousand have worked fine. I have used AA9 in less-than-max 357 and 44 loads with great results with standard weight boolits. For me, light 357 boolits never worked good.

[375RUGER]

I keep my powder and primers in a fridge too, BUT it's OFF. It's an insulated box to reduce temp variations. You don't need to refridgerate your powder and primers. I also have a wooden chest 1" thick walls with 2" foam insulation also for storage.