Nice AA #9 /Hornady 180 grain HAP load

[cwall64]

I have decided that AA #9 is my powder for 10mm.  I was testing with a Glock 20 Gen4, 24 lbs RSA, and KKM barrel (standard length), target was 15 yards from me with chrono at 10 feet, shooting off bags.  Max charge of 13.5 grains of AA #9 seemed a little too stout for me, but gave good chronograph numbers, so I went back to my workup research and loaded some at 13.1 (on Dillon XL 650 - using powder drop).  Side note is I wanted 13.0 grains, but had a hard time getting powder drop zeroed in on it, so I settled on 13.1 grains!  All new Starline brass.  And Accurate #9 was purchased this year when it started being available again.  (I was actually hoping to get average velocity around 1250 fps, so might drop another couple of 1/10s on next run)

String:   6   
Date:   7/18/15   
Time:   10:33:20 AM   
Grains:   180   
Hi Vel:   1275   
Low Vel:   1263   
Ave Vel:   1269   
Ext Spread:   12   
Std Dev:   3   
10mm AA #9 13.1 grains Hornady 180 HAP 1.250      
Velocity   Power Factor   Ft/Lbs
1271   228.78   645.603
1271   228.78   645.603
1269   228.42   643.572
1274   229.32   648.654
1266   227.88   640.533
1267   228.06   641.545
1275   229.5   649.673
1267   228.06   641.545
1267   228.06   641.545
1263   227.34   637.501



One issues i did have is some failures to feed, I assume it is from the 24 lbs RSA and was too lazy to dig out the 22 lbs one or the stock one as no changes have been made to the XL650 and all other rounds out of it have been fine (OAL 1.250", crimp 0.422" - 0.423" finished product fit Dillon 10mm case gauge).  Slide seemed to be catching the top part of the shell casing instead of the end of the case on a few shots.

Data from 13.5 grains:
String:   4   
Date:   6/6/15   
Time:   9:20:40 AM   
Grains:   180   
Hi Vel:   1307   
Low Vel:   1288   
Ave Vel:   1298   
Ext Spread:   19   
Std Dev:   6   
AA #9 13.5 gr - Hornady 180 gr HAP - Federal 150M - OAL 1.250      
Velocity   Power Factor   Ft/Lbs
1303   234.54   678.52
1303   234.54   678.52
1303   234.54   678.52
1299   233.82   674.361
1288   231.84   662.988
1288   231.84   662.988
1307   235.26   682.693
1295   233.1   670.214
1294   232.92   669.18
1300   234   675.4

[The_Shadow]

Some great numbers!  Hornady does make some great bullets...thanks for the range report!

[Taterhead]

Good shooting!!

A9 is my favorite 10mm powder too. Hornady XTPs and A9 are tough to beat for accuracy. The ONLY downside to A9 is that it is not efficient. Those hefty charge weights will suck down a can of powder pretty quickly. But since powder is the least expensive part of the equation, it isn't a big deal.

I too had the identical issues with heavier spring weight and heavy 10mm loads. The stock RSA cleaned that up 100%.

[RJPDVM]

I had the same result w/Longshot and AA9. I finally found I had over sprung. The key came whenI aded a polyurethane buffer to the RSA and the failures to feed increased dramatically., pulled the 22# spring and buffer and all is well in the world again.

[halfglocked]

 wow that is a nice group and as far as your Dillon I wouldn't  know about that ,that is a Dream set up for me all I have is. Lee breech loading single stage but I did run into some similar  problems with FTF's when I first tried a 24#rsa with stout loads of longshot and berry's  180 fmjs when I switched  to the 20# and oem rsa the FTF's  stopped bit I  got slightly  better groups  with the 20# rsa .