Load for AA5 with 124 rmr bullet,9mm

[egd]

I'm trying to expand my list of usable powders and bought a pound of AA5 to try. I've been checking for load data and frankly, I find listings all over the place. I've tried the company website,Lymons 49th, and Lee, plus searched using google. I've found max loads listed as from 5.8(Lee) to 6.4(Accurate site).
I'm using the RMR 124 RN bullet and an OAL of 1.135. I have one batch loaded at 5.8gr. I'm not sure whether to try 5.6 or 6.0. I've read that this powder works best at mid to higher levels, but I'd like to stay closer to mid level if possible.
So, what do you wise reloaders say should be my next load? What is your experience with AA5 and 9mm? Thanks

 

[sl33py]

I'm no expert as a new reloader, but i've heard pretty consistently to start low and work your way up.

How i've done this is to start at the minimum recommended charge weight and then .2 increases to max or close to max. I then have chrono'd them so i can both build a fun "plinking" or plates load vs a minor power factor or "factory" strength load.

I try to grab at least 2-3 of the spent shells (indoor range w/ a lot of brass on the floor) and check my primers before going up to the next charge weight. Just being cautious for over-pressure signs.

If you have the Lyman, Lee, and manufacturer's web recommended charge weights - unless you are trying to minimize the low end charge weights, i'd start at the min. Some try to save time by going mid-charge -10%. Less loads to work up.

I looked in my Hornady and only see AA7 for 9mm 124 FMJRN.

GL!

 

[LiveLife]

You are often going to get most current tested load data from powder manufacturers' online load data.

Accurate has load data for Berry's (BRY) and Ranier (RAN) plated 124 gr RN and I would reference them for RMR plated 124 gr RN - http://www.accuratepowder.com/wp-content/uploads/2011/01/accurate_load_data_3.5.pdf

124 gr BRY RN No. 5 Start 5.6 gr 977 fps - Max 6.3 gr 1,104 fps 34,132 PSI 1.160" COL

124 gr RAN RN No. 5 Start 5.6 gr 986 fps - Max 6.4 gr 1,118 fps 34,451 PSI 1.160" COL

While 1.135" OAL/COL will work for 124 gr RN, I have used longer 1.160" for RMR 124 gr RN to reduce gas leakage for greater accuracy but if you want to use 1.160", make sure the round will freely drop in the chamber and reliably feed/chamber from the magazine.

Since Accurate load data was tested with longer 1.160" COL, consider reducing the max charge when using shorter 1.135".

With 1.135" OAL, I would start at 5.6 gr and work up 5.8, 6.0 gr and see how accuracy trends.

 

[egd]

Yes the ranier data from Accurate is what I saw first and why I started with 5.8 since 6.4 was max. Then I saw where Lee had 5.8 as max. then the more I looked I found other "maxes". So I thought someone here has surely found a good load for them. And I know every gun is different, but I'd still like a few loads that have worked well for others.
ETA- yes I THINK 6.0 would be fine and that is what I was originally planning.

 

[Dudedog]

Off thread a bit but,
I haven't used AA#5 but I have found the RMR 124 9Mm FNs work well for me with a couple different powders between 1000 and 1050, most of my favorite loads are around 1050fps from a 5" barrel 9mm 1911.

 

[eo1bart]

I use 5.1gr AA#5 with Bayou 124gr RN coated lead bullet @ 1.12 OAL.
It is soft shooting and accurate in my Browning Hi Power.

 

[LiveLife]

eo1bart, coated lead bullets are typically sized larger at .356" and like .356" sized lead bullets, will require less powder charge than for .355" sized jacketed/plated bullets.

OP is using 124 gr RMR RN bullet that is likely sized at .355" at 1.135" and your larger sized coated lead bullet is seated deeper at 1.120". Plated bullets with rounded base tend to leak more gas (especially .355" sized bullets in oversized barrels with .356" - .357"+ groove diameter) and will require more powder.

It maybe the reason why RMR sizes their 115 gr HM RN larger at .356" instead of .355".

 

[ArchAngelCD]

I haven't found any of the Accurate AA powders to need to be loaded to the upper limits of the pressure range like some of the powders I us. (HS-6) I think AA#5 is a good choice for the 9mm and if 5.8gr is delivering an accurate load keep using it. If not you can bump the charge up .2gr and see if that's better. Accuracy is more important than higher velocity.

 

[egd]

I just went and shot some of my 5.8 and 6.0 loads. One (from a rest) grouped about 3" high at 15 yds. The other was about 2" left. So I'll just use 5.9 and call it good.