The revised AA powders manual #2, available on their site, lists the pressures for many revolver loads in CUP units.

The latest downloadable manual on the same site for AA powders lists the same bullets, loads and pressures but labels the pressures as PSI.

Identical bullets, loading data and velocities listed as well as pressure numbers in the 45 Colt for Ruger and Contender loads I checked but the claimed units of pressure measurement have changed.

Something is rotten here I believe.

If you are concerned I'd contact the manufacturer.

There is no easy conversion from psi to CUP and vice versa.

my first guess would be that the left hand dont know what the right hand is doing between the lab and the editor

They explain on the website that some of the data in the revised #2 have been changed, and that you should rely on the current numbers.

Pinky;

Not what I am referring to. Some of their data is unchanged between the two publications other than the claimed units of pressure for the loads. Everything else is EXACTLY the same.

CUP and PSI pressures are not normally the same for a given load so one or the other listed pressure designation appears to be incorrect. Probably not worth worrying about but I hate inconsistencies in reloading data. Too long working as a QA engineer I guess.

If the #2 says CUP and the website PSI, it's PSI. According to them, anyway. Like they say, if the #2 says one thing, and more current data another, forget what #2 says.

I would agree except that some of the data listed, such as the 357 Magnum, is as much as 10,000 over the current SAAMI PSI limits for the cartridge.

357 Magnum SAAMI CUP limits are/were 45,000 while SAAMI PSI limits are 35,000. The manual lists loads to 45,000 PSI which from a potential liability standpoint cannot be correct.

In the .PDF and loose leaf load data versions, there's a little footnote under the .357 data saying "Bold Italicized = CUP Pressure".

That said, some of the .357mag data is REALLY HOT. Look at their listing for AA #9 with a 158gr Hornady XTP. They list 13.5-15gr. The current Hornady and Speer load manuals both top out well below that 13.5gr start. (I don't have them in front of me right now or I'd quote the exact numbers)

I loaded and shot some 158gr XTPs with 13.5gr of #9 yesterday and I can attest to the fact that they were at least pushing the limits. I had sticky extraction and flattened primers in my 686. Recoil and muzzle flash were fairly impressive too. I doubt I'll be going back to this particular load any time soon.

13.4gr of AA#9 w/158hp/xtp WSP or GM100 is my favorite load for my 2.75" Ruger Sec. Six

The problem lies with AA, they have their powder manufactured in several countries which cause lot variations

Well, I don't understand why, in this day and age, that we can't have PSI data for everything.

quote:

Originally posted by jibjab:
13.4gr of AA#9 w/158hp/xtp WSP or GM100 is my favorite load for my 2.75" Ruger Sec. Six

Interesting you should say that. I went back through my logbook and found that I'd loaded the same combination (158gr XTP, AA #9) at 14gr for use in my Marlin 1894 rifle a year or so ago. So I took the remainder of the loads that showed such extreme pressure signs in my 686 back to the range, and shot them through the rifle.

NO pressure signs at all, over the 75 or so rounds I had left. The primers all had their nice original rounded shoulders left.

Conversely, every round I fired in the 686 (during the first trip to the range) showed severely flattened primers and required a good thwack on the ejector to get the cases out.

The 686 is a no-dash 2.5" that HAS had the firing pin bushing recall performed, and just came back from S&W after being bead blasted. I haven't shot it very extensively, and I've never shot this particular load through it before. I did shoot some 158gr Federal Hydra-Shoks and a bunch of light lead .38spl loads through it in the same range session without any sticky extraction.

Ideas?

Oh, I should add that I'm using WSPM primers (which is what is listed in the AA load data) and Federal nickel brass that's been fired 2 times.

I had a interesting experience loading AA#9 for a Colt Trooper .357 Magnum(pre mark series) I was working up loads with Nosler 158gr JHP using WSP primers, I started at 12.2gr of #9 to 12.8 in .2gr increments I had flattend cratered primers along with sticky extraction at 12.8grs. From the same batch of AA#9 and the same batch of primers I loaded 13.0 though 13.6gr of AA#9, at 13.2 the over pressure signs went away and returned at 13.6gr. The 13.2gr load was the most accurate, can anyone explain this to me ?