AA#9 mag primers or no?

Accurate Arms manual #1 used standard primers testing their loads. Later data uses magnum primers. I use CCI 500 primers with AA#9 with data from their 1st manual. Gives consistent velocities with no issues. Possibly in very cold temps a mag primer would be better? I shoot 158 grain Hornady XTP's with CCI 500's using maximum data from manual #1 and it is extremely accurate in both a 6" revolver and my Marlin carbine.
AA manual #1 doesn't recommend AA#9 with 125 grain or lighter bullets. They used CCI 500 with Hornady Frontier cases. With 158 XTP's they used a start charge of 11.7 to a maximum at 13.0 grains. Speer 140 JHP from 13.0-14.4. Nosler 150 JSP from 12.5-13.9. Hornady 180 XTP's from 10.5-11.7 grains.
I'd use the primer they use from whichever data manual or on-line data they publish. You know that you have to trim your cases shorter loading the FTX bullets. 1.250" maximum case length with the FTX bullet.

Searching load data for component applications is a primary among reloading safety steps. It didn't take me more than a minute or two to find out which published primer to use for AA#9 and 140's. (SPP)
Buy some books and read them cover to cover.
GS

dragon68 said:

I am going to try my hand at loading some ftx 140 gr. for my 357 mag and the info i have found only gives #9(of the powder i have). I would like to use 2400 but there is no info for it :banghead:. The #9 i have is about 20 years old so my next question is how do i know if it is good?

Thanks lots
Tony

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Alliant supplies data for a 140gr Speer bullet that should be fine to use with a 140gr Hornady FTX bullet. Of course you will have to work up to the Max and chack for pressure signs along the way. The data on the Alliant Site is the Max charge, drop back 10% for the starting charge weight.
http://www.alliantpowder.com/reloaders/recipedetail.aspx?gtypeid=1&weight=140&shellid=28&bulletid=37

I'm seeing some good chronograph numbers with CCI magnum primers in 357/44mag and 10mm compared to WLPs.

Start low & work up.

20 yr old powder can be good - depends on how it was stored.
If it's in a closed container, I'd bet it's fine.

With AA9, I think I would use magnum primers.

Unless the load data specifies a mag primer, don't just drop in a mag primer.
20 year old powder? Why, it is still in its youth.
My Bullseye and Unique are from the late '70s and early '80s and they are still the same as the day I bought them.

I've used both types of primers in loads with AA9. CCI standard and mag in the .357 mag and Winchester LP primers for "standard and magnum" in the .41 mag. Didn't get any real differences with the CCI's though the mag primers generally produced loads with lower SD's and extreme spread when chrono'd by a small amount.

.357 Magnum with Accurate #9 Powder

Accurate #1 Manual Standard Primers, 35,000 psi loads

Accurate #2 Manual Standard Primers 45,000 CUP (heavier loads than shown in the #1 manual)

Since Western Powder bought out Accurate Magnum Primers 35,000 psi - lower powder charges than the Accurate #1 manual.

There is no reason not to try either type of primer, as long as you use start loads and then work up. That's the procedure. You can judge for yourself whether either type gives you an advantage with the powders that you wish to use. The only rule you need to remember is do not substitute a magnum primer for a standard primer with maximum pressure loads, as you need to back off at least 5% for safety sake.


NCsmitty

Late to the party but wanted to say that it should not be necessary to run Magnum primers w/ AA9. I run 33+ gr. charges of AA9 in my 500 S&W and have never used anything but standard primers and have never had a problem. They're LR not LP of course, but still.

Let's see:

Pressure standard lowered in change from CUP to PSI.

Accurate Arms Manual #1 standard primers & PSI data.

Accurate Arms decides PSI data for .357 is not sufficiently powerful - re fires all .357 data to CUP standard - Remains with Standard Primer

Accurate Arms bought out by Western Powder. Western reduces load pressure to PSI standard. This time with even lower charge weights now with magnum primers. They ostensibly fear reloaders will use magnum primers regardless of type recommended. Setting up the data with unneeded magnum level primers renders the data "safe" under the reduced psi standard regardless of primer type used.

No wonder reloaders are confused! :banghead:

RMc said:

.357 Magnum with Accurate #9 Powder

Accurate #1 Manual Standard Primers, 35,000 psi loads

Accurate #2 Manual Standard Primers 45,000 CUP (heavier loads than shown in the #1 manual)

Since Western Powder bought out Accurate Magnum Primers 35,000 psi - lower powder charges than the Accurate #1 manual.

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The pressures in those 2 loads are probably much closer than you might think. Manual #1 is using PSI and Manual #2 is using CUP.

No need for magnum primers. Haven't needed them since 1991. Worked up loads for 357, 44, and 30 carb. and didn't find a need for mag primers even in use for temps. down into the 20's. YMMV, no warranties expressed or implied, my own personal experience, etc.

ArchAngelCD said:

The pressures in those 2 loads are probably much closer than you might think. Manual #1 is using PSI and Manual #2 is using CUP.

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The change from CUP to PSI resulted in a reduction of pressure and performance for the 357 magnum. Accurate arms returned to the higher pressure, larger powder charges and higher velocities of the CUP standard with their 2nd major loading manual.

The second Accurate Manual with a reshoot of all .357 magnum data to the CUP standard represents hard evidence for the reloading public to reject the current babble about maximum average pressures in the .357 being the same under the different standards.