AA#7 Loading data

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gscottfl

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I just picked up some AA#7 to load up some 9mm rounds with a 125 gr, cast bullets. While checking my load data I found a huge difference in what my books say and what Accurate Arms Data says from their web site. For instince, my book says starting load is 7.5 gr and the online data says 5.7 gr. Any one have any idea's ?
 
When in doubt, go with the makers data. I haven't used AA #7, so I can't really help with personal data, but 7.5 sounds high for a starting load with 124/5 Gr lead in 9MM. I have used a lot of AA #5 in the 9MM, but with lead I used W231.

Welcome to THR.
 
+1 for what Walkalong says. Variations in published data is the norm in this hobby. If you go with the manufacturer data for that bullet, you'll be OK so long as you still do a proper load work up.
 
7.5 sounds about right to me. AA#7 is a really slow-burning powder and it takes a lot.

I just looked up Blue Dot load data in Alliant's load book before they switched everything to soft Speer bullets. It says 8.2 grains max with 125 grain cast bullets, and AA#7 should be in the same ballpark (probably just a little higher, like 8.5)

One thing to watch out for tho' is the overall length. In some cartridges it doesn't matter much, but 9mm isn't one of them. Don't seat the bullets too deep or the pressure can run way up on you.
 
Accurate data I have downloaded 2008 had 7.4 to 8.2 grs of No 7 with a 125gr Lead RN in the 9mm using WSP primer.

Load data downloaded today has 5.7 grs to 6.5 grs for the 125gr Lear RN with WSP primer.

Prosper load procedure would be to start at the lower charge in the latest data, use a chrono and work up carefully and see if the new Accurate data is giving the velocities they say or if you have to go higher to the older data. Check for pressure signs and find the best load for your particular bullet.

Changes in load data could indicate differences in current powder.
 
Thanks, I agree I am going to start with the new data from the manufacturer and work up the load
 
You'll find that #7 likes to be run on the higher pressure side. At lower pressures, it is less consistent and doesn't burn completely. Accurate recently castrated several loads; I don't know why but they reduced some significantly.
 
Load data does vary a lot. For Bullseye in 9MM with 124 gr. jacketed bullets, my Hodgdon manual says 3.8-4.2. The Alliant booklet says 4.9. I'll start with 4.2, may leave it at that if everything works out. My handgun experience with regards to loading is less is better than more, at least for my purposes.
 
Call Accurate Arms/ Western Powders or email them before loading!

I checked my 3.4 load guide, notes, Lyman and other manuals and that load data looks like 147 gr. lead data. That starting load may well be in squib territory. There is just far too much of a drop in that data from previous works to not be a mistake! The "New" top end of the scale does not even meet the previous starting load by a fair stretch. Unless they significantly reformulated their powder, something doesn't seem right at all.
 
I heard from Accurate Arms today as to why the varience. He said that when western powders bought accurate arms they re-ran all of the 9mm loads with new testing equipment, and different components. They also reduced the min AOL which resulted in higher pressures. In a nut shell the new data in 3.5 manual is correct and that I should build my loads off of that.
 
Drastic changes in all Accurate centerfire pistol load info within the last year. Go by their web site or order their latest reloading guide.
 
Aa # 7

I've used A lot of AA # 7.

For NRA action pistol:
122 gr LFP, 125 gr LRN, 124 gr plated TC. I use 7.0 gr AA #7 should give @ 1025 fps from 4-4.5 in barrel. Federal SP primers.

For general shooting.
124 gr Plated JHP & RN, 124 & 125 gr FMJ. I use 8.0 gr AA #7 should give @ 1150 fps from 4-4.5 in barrel. Federal SP primers. OAL 1.150 to 1.160 in.

Getting close to NATO spec 9mm.
124 gr FMJ, 124 gr Plated JHP, I use 8.8 gr AA #7 should give @ 1220 fps from a SIG 226. Tula SP Primers. OAL 1.150 to 1.160 in.

Use any data at your own risk as your milage may vary. I generally work up a load for the firearm and evaluate it in various arms to see that it performs to my specifications before loading it in mass 10-15K normally.

Remember if you shoot lead, burning powder will cause smoke which makes follow up shots harder to see and if you push it to much you will get leading in the barrel.
 
Drastic changes in ALL of Accurate's data, rifles and pistols. I used #7 for years, and all of a sudden my Phantoms's favorite cast load went from middle of the road to +P.
But for you use, I use a 125 grain cast LRN lubed with Lee Liquid Alox on top of 6.4 grains #7 to good effect in my CZ P-01 @ 1.095. That load is light recoiling and quite accurate, even though it was UNDER the minimum reccomended by the last manual. Now it is close to the top of the lead data.
 
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