AA9 in my G20 and Storm Lake barrel

[Spudmeister]

Hey Guys,

I'm not new to reloading 10mm but am quite new to using AA9 in 10mm.  I'd like to go over today's results and get the thoughts of those to work with AA9.

The gun is a G20, Gen 3, 20# recoil spring and a 5.3" Storm Lake barrel.  All chrono readings are a 5 shot average.

Test 1 uses Starline cases, CCI STD primers and Hornady 180gr XTP bullet seated to 1.255"

12.9gr AA9 gave 1,130 fps with low es
13.2gr AA9 gave 1,163 fps with low es
13.5gr AA9 gave 1,160 with low es.  This is the max load Accurate Arms gives for this combination.  Yet the Hornady manual says the max load is 14.9 gr of AA9.

There are no signs of the loads being hot or over pressure.  So, all things being equal (they never are), do you think the AA9 will respond well to increasing the load above 13.5gr.  I am not looking for nuclear loads but was hoping for 1,250 fps out of this longer/tighter barrel. 


Test 2 uses the same everything of test 1 except the bullet is a 200gr XTP

11.9 Gr AA9 gave 1,060 fps and a low es
12.2 gr AA9 gave 1,088 fps and a low es
12.5gr AA9 gave 1,104 fps and a low es.

Again, there are no signs of high pressure.  My guess is the 12,5gr 200 load has less pressure than the 13.5gr 180 load.  But 12.5gr is the Accurate Arms max yet Hornady shows a max of 13.2gr AA9 with the 200gr XTP bullet.  I am not looking for nuclear load but was hoping to break 1,150 fps with this powder.

There has not been a direct comparison to my much loved Longshot powder but the AA9 seems to be softer shooting with a reduced slide velocity.

Please chime in with any practical advice you may have.  Thanks

[Ridgerunner665]

I'm not telling you what to do, just stating what I have done.

13.2 grains under a 200 grain XTP is "getting" warm, but I believe it to be safe....I fired that load through both the stock barrel and the KKM, no problems with either one.

I haven't done anything with 180 grain bullets, but I did fire a few 190 grain bullets with 13.4 grains of #9.

[Texashogman]

I'm pretty new to the 10mm but a few weeks ago I shot 180xtp's with No.9 in my 6" RIA with starline brass and std cci primers loaded to 1.26"--chrony was 8' from muzzle and I am at 5500msl
I had up to 14.5grains loaded but stopped at 14.2
13.3 got 1310fps
13.6 was 1350
13.9 was 1386
and 14.2 was 1400fps

I could have shot the 14.5grain load also but I wanted to come home and measure the brass to check for head expansion --- all of those loads and the factory 180 fmj sig loads the brass measured the same so no "belly" present -- primers were getting flat near the top, but still had a slightly round edge to them--just starting to see a very slight firing pin extrusion mark on the primers @ 14.2 so I bet the 14.5 will be MY max for my gun ---did not test for accuracy yet

[Spudmeister]

Thank you for your input guys.  You gave me enough confidence to push the loads further... Though within Hornady limits.  If all goes well I'll test them tomorrow and report back.

[Spudmeister]

It was a good time over the chrono today.  While not all the results were positive, I found out what I wanted to know.  And I wanted do know what AA9 would do in my G20's with 180 and 200 gr XTP's.

In an earlier post my previous loads are listed with results.  Here are today's results. Everything, unless noted, is the same as the last post.

180gr XTP with 5.3" Storm Lake barrel

13.8 gr of AA9 gave 1,189 fps es is 57
14.1 gr of AA9 gave 1,212 fps es is 24

The goal was 1,250 fps.  Recoil, slide velocity and brass throwing are all very intense.  Primers are not flat but showing pressure.

BUT.. shoot the 14.1gr load out of the 4.6" OEM G20 barrel and the MV is 1,148 fps and es is 40.  This was an obviously less intense load with the larger OEM barrel/chamber.  Of course at 1,148 fps it should be soft easy shooting.

200gr XTP with 5.3" Storm Lake barrel

12.8 gr of AA9 gave 1,120 fps and es of 12
13.1 gr of AA9 gave 1,156 fps and es of 14

1,150 fps was my goal for this bullet.  Pressures seem quite normal and primers still have a full radius on them (unlike the 180 gr loads above).  IMO this is not the max load I can achieve.  Rather, this heavier bullet seems just right for AA9 to give max performance.  Some of this is data and some is opinion.

I also shot the 13.1 gr load out of the 4.6" OEM barrel.  MV was 1,093 fps with and es of 8. 

Again, you can see that AA9 is very much in its element base on this limited testing.  I'm not impressed with the 180gr XTP results but am quite impressed with the 200gr XTP results.... and there is more room above what I have loaded with the 200gr bullet. 

Texashogman... I do know know how you get your velocities.  Partly the long barrel of course but maybe your +5,000 ft elevation moves bullets along faster than my 500 ft elevation

Ridgerunner... Looks like our results about match each other. 

And finally, one of the nice things about the 10mm is it can be loaded in great part to the tolerance of the shooter.  I tend to stay below the nuclear level but it's a matter of personal taste within some broad limits.

Thanks guys!

[Texashogman]

Spud-- it's gott be the barrel...the ria 52000 is marketed as a match 6" lapped barrel...there is another member here getting almost the exact same speeds as I am with very similar loads...he went up to full max book with the 180xtp and got some pretty impressive speeds.

The chamber in my barrel is nice and tight and I think the lapped factory match barrel helps the speeds too....my personal max for the 180xtp with #9 Is at 14.5, he went up to the book of 14.9 ....and yes, it's an impressive load with brass ejecting to mars.

[Spudmeister]

Spud-- it's gott be the barrel...the ria 52000 is marketed as a match 6" lapped barrel...there is another member here getting almost the exact same speeds as I am with very similar loads...he went up to full max book with the 180xtp and got some pretty impressive speeds.

The chamber in my barrel is nice and tight and I think the lapped factory match barrel helps the speeds too....my personal max for the 180xtp with #9 Is at 14.5, he went up to the book of 14.9 ....and yes, it's an impressive load with brass ejecting to mars.

Yes... that makes perfect sense.  There is a big velocity difference from the OEM to the slightly longer 5.3" Storm Lake barrel.  It's very reasonable that your longer and very premium barrel/chamber would give you that nice jump in velocity.  I imagine it would also jump the pressure but it's well contained in the tight chamber.

[Spudmeister]

A few years ago I developed a good load (for me) with Longshot and the 200gr XTP bullet.  It is 8.2 gr of Longshot and has been very accurate for me though I never shot it much.  But it seemed appropriate to compare this load with the best AA9 load I could come up with.  That is 13.1gr of AA9 listed above.  Brought out a few more guns to give a decent comparison.

BTW... extreme spreads were all in the typical range. They are far too easy to over analyse and can change from day to day.

G29 with 4.5" Storm Lake barrel   21# springs

Longshot    1111 fps
AA9            1107 fps
---------------------------------

G20 with 4.6" OEM barrel   20# spring

Longshot      1103 fps
AA9              1093 fps
------------------------------------

G20 with 5.3" Storm Lake barrel     20# spring

Longshot        1156 fps
AA9                1156 fps
-----------------------------------

G40 with 6" OEM barrel        OEM spring

Longshot          1132 fps
AA9                  1143 fps

My surprise was that 2 pretty different powders tracked velocity so well in different guns/barrels.  They certainly were not the same when they fired.  You could feel the greater slide velocity or bump of whatever that the Longshot gave over the AA9.  In the  G40 the AA9 load LITERALLY just dribbled the brass out while the Longshot gave it is more reasonable throw. 

It was only after loading the Longshot loads last night that I noticed I was crushing the load with AA9.  Not a big deal but enough that the seating die had to be backed out .020" to achieve the same bullet depth when loading with Longshot. 

In conclusion, this is all an abstract to me since I so much prefer the Montana 200gr WFN hard cast bullet with Longshot.  I know this is blasphemy around here but I prefer the Longshot over the AA9 for heavy bullet loads.  Many video's on You Tube suggest the 200gr XTP does not open well under 1,100 fps.  My loads do not go much above that.  Plus ... that 200 gr WFN is easy to run at 1,250 fps out of either the 5.3" Storm Lake barrel or the 6" OEM G40 barrel.  And that is with Longshot.

I learned a bunch of stuff I did not expect to and the few things I was looking to learn.  Hope you got something out of it too.