aa#7 powder for 9mm major~

[chgofirefighter]

Looking to load 9mm major using aa7 powder, a good friend recommended 9.3 gr to start with than possibly 9.25.  What are you guys using to make major power factor with 5.25 barrel, comp and popple holes CK Arms? Doing some research I've seen numbers up to 9.8 gr which seems like a lot of powder to me but what do I know? I'm doing some research and learning as I go...  

 

Thanks in advance~  

[superdude]

What bullet and weight?

[36873687]

I’ve given u the load an chrono info. 9.7 to 9.8 is with jhp 124. U are using .356 125. Trust me all the test have been done in the gun it’s a gift  

[chgofirefighter]

5 hours ago, superdude said:

What bullet and weight?

125 gr the blue bullet~ Sorry, neglected to add that detail in my post 

[chgofirefighter]

5 hours ago, 36873687 said:

I’ve given u the load an chrono info. 9.7 to 9.8 is with jhp 124. U are using .356 125. Trust me all the test have been done in the gun it’s a gift  

lol~ Yes indeed~  Just want to see what else is everyone is working with... Loaded to 9.3 for now~  Testing tomorrow or thursday~ 

[racer-x]

You need to plunk test your barrel 1st to determine max OAL before bullet contacts throat. 1.150 OAL contacted throat with MG JHP's in my 2 CK Thunders when new - I loaded to 1.130 max OAL until I had my barrels throat reamed. OAL of your load is a big part of the equation. Shorter OAL = higher velocity & pressure.

 

After you determine the max OAL for your barrel, then you can subtract at least .020" from that to get your desired OAL. In general, a longer OAL is better since it will help to reduce max chamber pressures. You need to have a small gap between bullet and throat, or your chamber pressures will be much higher. The other extreme is you need to have enough bullet in the case to hold it securely. My experience is 1.165 max OAL for MG115JHP, and 1.185 max OAL for MG124JHP is optimum (assuming these pass plunk test in your barrel with at least .020 to spare).

 

I recommend you then do a ladder test with chrono to determine what velocities are in your gun (ie. load 10 rounds at 9.2, 10 at 9.4, 10 at 9.6, etc.).

 

This is what my 170PF loads were for my CK thunders when they still had stock size popple holes (3x1/8").

AA7 9.2 grains 1.130 OAL MG124JHP

AA7 9.7 grains 1.185 OAL MG124JHP (AFTER barrel was throated for longer loads)

 

I've since enlarged the popple holes to 3x 3/16", so the loads were increased a little to account for bigger holes in barrel:

AA7 10.0 grains 1.185 OAL MG124JHP

AA7 10.7 grains 1.165 OAL MG115JHP

[36873687]

26 minutes ago, racer-x said:

You need to plunk test your barrel 1st to determine max OAL before bullet contacts throat. 1.150 OAL contacted throat with MG JHP's in my 2 CK Thunders when new - I loaded to 1.130 max OAL until I had my barrels throat reamed. OAL of your load is a big part of the equation. Shorter OAL = higher velocity & pressure.

 

After you determine the max OAL for your barrel, then you can subtract at least .020" from that to get your desired OAL. In general, a longer OAL is better since it will help to reduce max chamber pressures. You need to have a small gap between bullet and throat, or your chamber pressures will be much higher. The other extreme is you need to have enough bullet in the case to hold it securely. My experience is 1.165 max OAL for MG115JHP, and 1.185 max OAL for MG124JHP is optimum (assuming these pass plunk test in your barrel with at least .020 to spare).

 

I recommend you then do a ladder test with chrono to determine what velocities are in your gun (ie. load 10 rounds at 9.2, 10 at 9.4, 10 at 9.6, etc.).

 

This is what my 170PF loads were for my CK thunders when they still had stock size popple holes (3x1/8").

AA7 9.2 grains 1.130 OAL MG124JHP

AA7 9.7 grains 1.185 OAL MG124JHP (AFTER barrel was throated for longer loads)

 

I've since enlarged the popple holes to 3x 3/16", so the loads were increased a little to account for bigger holes in barrel:

AA7 10.0 grains 1.185 OAL MG124JHP

AA7 10.7 grains 1.165 OAL MG115JHP

Barrel was reamed it is fine long. Sent back to Bobby 

[chgofirefighter]

Testing went well, using 125gr blue bullets, 9.3gr of aa7  and 1.65/68 OAL yield me 171 PF no problems, good stuff.  I want to try SWMP powder as well too~  So far this is best flowing powder I've used compared to HS6.  Very accurate drops, love it!  

[Dan4147]

On 12/20/2019 at 12:44 PM, chgofirefighter said:

Testing went well, using 125gr blue bullets, 9.3gr of aa7  and 1.65/68 OAL yield me 171 PF no problems, good stuff.  I want to try SWMP powder as well too~  So far this is best flowing powder I've used compared to HS6.  Very accurate drops, love it!  

 

So, I don't claim to be an expert but have experience on what I have done personally (with #7 and coated bullets on a V12 gun).  Try this just to see if you have some of the same.  Next time you go practice lay a tarp out where your brass is falling.  Shoot a 100 or 2, then lift the corners of the tarp to pile up the brass.  Underneath and mixed with the brass you will have a pile of "corn meal".  Some grains will still be in your gun.  In other words, I loved #7 but couldn't get it to clean up, with various major test loads.

 

Blue Bullets.  I love them for pcc and minor.  With a ported and poppled barrel, over time, you may find the popple holes getting smaller, and the bottom of your comp getting shallower.  Of course, it depends on everything involved, and the position of the moon.

 

Merry Christmas!

[PhotoRecon]

I'm testing AA#7 in my Czechmate with Acme 115 RN new version.

 

Worked up to 9.8 grs. at 1.155" so far with no problem signs and a SD of 6.8. On my old Pact Professional chrono I'm at 170 pf but on my Chrony it's 178 pf. Got a couple fellow shooters with chronos to see what velocity they show.

 

With my borescope I see some incompletely burned powder but not very much. So far that hasn't resulted in any problem that I can identify.

 

Edited December 31, 2019 by PhotoRecon
Added punctuation

[Sfisch0311]

Just out of curiosity, why are you loading coated bullets for open? You’re going to get a lot of lead fouling in the comp that’s going to build up a lot over time. I’d recommend a jacket bullet, HP’s definitely. You can get Precision Deltas for a really great price for 2k. 
 

But to touch in the load data, I run AA#7 with Zero 115gr Conical HP and I love how gassy this powder is. I have a shorty with 2 popples and I have to run 11.3gr at 1.160 OAL . Yes I know that’s a lot, you should see the looks I get from people when I tell them how much powder is in there lol. It makes 173 PF out of my gun and I use Win SR primers. I used to use HS-6 for a long while and may still try out some loading with it again, but I just really like how the gun tracks with the AA7. Also, I get much more consistent throws with AA7 than H-6.
 

 

Edited February 11, 2020 by Sfisch0311

[chgofirefighter]

On 2/11/2020 at 8:57 AM, Sfisch0311 said:

Just out of curiosity, why are you loading coated bullets for open? You’re going to get a lot of lead fouling in the comp that’s going to build up a lot over time. I’d recommend a jacket bullet, HP’s definitely. You can get Precision Deltas for a really great price for 2k. 
 

But to touch in the load data, I run AA#7 with Zero 115gr Conical HP and I love how gassy this powder is. I have a shorty with 2 popples and I have to run 11.3gr at 1.160 OAL . Yes I know that’s a lot, you should see the looks I get from people when I tell them how much powder is in there lol. It makes 173 PF out of my gun and I use Win SR primers. I used to use HS-6 for a long while and may still try out some loading with it again, but I just really like how the gun tracks with the AA7. Also, I get much more consistent throws with AA7 than H-6.
 

 

6k loaded thus far, no fouling or issues.  I've been using Blue Bullets without a problem, their coating is a lot different than all others.  I'll be trying PD's soon~  but for the meantime, the blues are working just fine! Thanks 

[Sfisch0311]

22 hours ago, chgofirefighter said:

6k loaded thus far, no fouling or issues.  I've been using Blue Bullets without a problem, their coating is a lot different than all others.  I'll be trying PD's soon~  but for the meantime, the blues are working just fine! Thanks 

Gotcha, I've just never been a fan of coated in comp guns (Open or otherwise). It all just comes down to personal preference really. Cheers!

[K-Texas]

On 12/20/2019 at 11:44 AM, chgofirefighter said:

Testing went well, using 125gr blue bullets, 9.3gr of aa7  and 1.65/68 OAL yield me 171 PF no problems, good stuff.  I want to try SWMP powder as well too~  So far this is best flowing powder I've used compared to HS6.  Very accurate drops, love it!  

 

Shooters World Major Pistol was once sold as Accurate No 7, before the US made version from St. Marks in FLA. Same case for No 2 and Clean Shot, No 5 and Auto Pistol. A comparison of Accurate No 7 and SW Major Pistol is something I'm interested in myself. In some data it's hard to know which powder was actually used. IIRC, there was also some concern that the older No 7/Major Pistol had some abrasive ingredients that some claimed were aluminum particles.

 

I do use the current No 7 with 147 gr. JHPs that are Major PF.