New to the long barrel 9mm game, recently built a 16" Ar9.   It seems to be very accurate with factory 115 grain, however, is there a better powder or projectile suited for the longer length?  Twist rate is 1:10.

I am in the process of building a pcc myself.  It will be for uspsa.  Everything I have been reading overBrian Enos in the PCC forum is claiming that you don't gain any velocity In 9mm with barrels over 8 inches using fast pistol powders like titegroup.  Some loads even lose velocity.

Dry flash I am curious how  your load compares in pistol barrel vs pcc barrel?   Have you chronoed it in both?  For competition in uspsa and steel some of the people are using the TACCOM 7.5 inch barrel with an aluminum shroud pinned to make 16 inch length.  Lighter mass makes transitions faster.  I know this is borderline reloading topic, but I would like to use the same 9mm load for both pistol(carry optics) and pcc and it has to make minor power factor in both.

I am undecided on barrel and maybe just overthinking it.  I was even thinking of using autocomp or something similar for 16 inch barrel, but would be easier to use same load in both pistol and pcc.

I’m actually working on loads for this sort of thing.  My criteria are that the loads need to run well in both pistols (and I have a variety of 9mm pistols to feed) and longer barreled guns like my 9mm ARs and my MP5 clone.  That means running well in 8.5”, 10” and 16” barrels.

I’m zeroing in on a load with True Blue and 124 grain FMJs, close to the max end to take advantage of the extra barrel length in the ARs.  I haven’t done any chrono tests yet, but it looks like getting 1100-1200 FPS out of the 4” pistol-length barrels will be the key to solid functioning in the whole range of barrel lengths.

As Dano says, it’ll be important to pay attention to tuning your carbine’s buffer and spring for the load you settle on.  I have run Winchester White Box 115s with a standard carbine buffer, and it “works” in both 10” and 16” configurations.  But with that standard 3 oz buffer, I have Blazer aluminum cased rounds shred themselves on ejection; that means the buffer and spring aren’t slowing down the bolt enough to keep it closed long enough.  It also makes it look suspiciously like Blazer Aluminum 115 grain loads are quite a bit warmer than WWBs are.

Personally I would go with 147 bullets.
During some testing I got basically the same velocities using 147 loads in a G17 and a JP 9mm 16 inch carbine.
The 115 loads were consistently 110-120 fps faster out of the carbine though.
If you are using the carbine for self defense the 147s would be ideal so that you don't end up using a bullet past it's rated velocity.

The slower burning powder makes sense to me for increasing velocity.  Most of the charts that I've seen show 10.5" nearing the optimum length for near max velocity and there are only minimal gains on a 16".

So typical long range shooting errors on a heavier bullet weight but let's assume 50 yards is sustainable with a 9mm.  Given the lower velocity and shorter range of the cartridge, does a heavier bullet weight actually reduce effective range?

I typically run 124 jhp in my glocks and they're the most accurate, however, 115's group best in my PCC.

Running a 7.5 oz buffer with an extra power 308 spring so +P ranges shouldn't be an issue.

I've been shooting my standard plinking load of 4.2gr of titegroup with 115gr Berry's
Sig MPX

I shot the same IDPA minor power factor load as my pistol for my 9MM PCC. No issues and accuracy was fine.

PCC is a CMMG 9mm. Load was 5.3 gr of WSF. 115gr FMJ’s from Armscor.

I use W231 in my 10.5" barreled 9mm AR. The barrel has a 5.5" flash hider on it till the Form4 comes back to SBR it.

I have to disagree.

I'm loading with Win 231, which has a burn rate similar to Tightgroup. I got the following, shooting a 115 gr. Berry's bullet on a 43°F day:

5.0" M11/9: 1235 fps
10.2" Uzi: 1310 fps
16.1" Destroyer: 1415 fps

The velocity increases with barrel length are not as great as when using a slower powder, but you still get a noticeable increase.

Use your pistol load, and you're pretty safe to make Minor in your PCC. I don't use a different load for USPSA in PCC vs Single Stack Minor.

When I get around to it, my thought is to make a ppc load using power pistol hoping the shot timer picks up the shots easier. We'll see I guess.

Thanks for your input, I definitely have a spring project to find my optimum bullet/powder for pcc.  I am just making it harder by chasing a load I can use in pistol too.  It might not happen, as I am leaning toward 115 coated for pcc.

Yes but reshoots suck.

I am going to use 147. That way I will have a load that works in both pcc and handgun.

I just got done loading another 1500 rounds for my AR-9. (PSA upper/glock lower)

I'm shooting x-treme bullets 147 gr. RN with 4.9 gr Power Pistol loaded to 1.13"  Averages 1188 fps  (ES 20, SD 6 - 10 shot string) out of my 12" bbl.  This shoots 3" groups at 50 yards with a Vortex red dot from the bench.

Long story:

I originally bought 10,000 rds of Precision Delta 124 gr. JHP to load up for this AR-9 (this bullet was the most accurate in my Glocks).  It turns out the throat/leade on this rifle is cut extremely short.  Due to the bullet profile, I had to load the PD's too short to reliably feed in order to get them to chamber without jamming into the leade and either setting back the bullet, or worse, having the bullet pulled when I mortared the AR to open the chamber, dumping powder everywhere.  Needless to say, I switched bullets.

The 147 gr. x-treme have a lot longer nose, so you can load them longer, which helps with reliable feeding into the AR.  Which is critical, because mag dumping this using 50 round Korean drum mags is fun as hell!  I did beat up the drum mag to the point of failure though (lips), so I have to find a new one.    Meanwhile the glock and Korean 30+ rounders also work nicely.

While working up loads for this (and before switching bullets) I did a ton of chronograph work comparing my AR-9 with my Glock 19 (all with power pistol).  The AR-9 regularly gained about 250 fps with the 124 grain bullets over the same load in the glock.  7 Loads using Power Pistol 5.0-6.0 gr in 0.2 gr increments with the 5.4gr at 2 different COAL's.

I haven't shot my 147 gr load through a glock yet to compare, as I'm loading those pretty much exclusively for the AR-9, and will use the 124 gr PD JHP's for the glocks.

For reference (124 gr Precision Delta JHP, Power Pistol, Win SPP, R-P nickel coated range brass) - forgive the formatting:

Load COAL Gun AVG VeL  ES    SD #shots Delta Velocity from long barrel
5.0 gr PP1.06"AR-9 1262 49 16 10 -
5.2 gr PP1.06"AR-9 1274 47 15 10    -
5.4 gr PP1.06"AR-9 1298 54 17 9 -
5.4 gr PP1.08"AR-9 1300 60 18 9 -
5.6 gr PP1.06"AR-9 1317 44 15 9 -
5.8 gr PP1.06"AR-9 1339 35 13 9 -
6.0 gr PP1.06"AR-9 1371 37 13 8 -
5.0 gr PP1.06"G-19 1005 15 6 8 257
5.2 gr PP1.06"G-19 1014 24 8 7 260
5.4 gr PP1.06"G-19 1051 59 17 9 247
5.4 gr PP1.08"G-19 1050 37 13 5 250
5.6 gr PP1.06"G-19 1067 46 13 8 250
5.8 gr PP1.06"G-19 1074 61 20 9 265
6.0 gr PP1.06"G-19 1095 63 18 10 276

BTW, Cabelas is having a sale on Xtreme bullets, and with their rebate offer of 100 pcs of free brass (yeah, free 10mm brass!), the price is actually reasonable.  9mm is so cheap now, it's hard to justify loading it, but I basically need these specialized loads for my AR-9.

Link to Cabelas X-Treme bullets  
Don't forget to put in for free shipping.

I'm running 147's over 3.5 grns of Bullseye in a 16" bbl. This is my load for my pistols as well as my mp5 and m16. I can hit a 12" gong at 150yards all day
I am running a 7.5 oz buffer on the 16" gun.

Thanks for sharing your data.   I was using power pistol in my .40 edge and g35.  I actually switched to titegroup.  Less felt recoil for me.  I was considering using precision delta 124 for my rifle.  Now I know to order small quantities until I am sure they will work.  I like heavy bullet/fast powder combo in pistol, not sure if it will transfer to PCC. I will be gathering data for 16 inch barrel, but it is interesting to see the comparison.  Just curious is your barrel with short throat a PSA barrel?

The upper was shipped complete from psa, so I'm guessing the barrel is their's.  I'll go check.

Looks like it.

It's marked "9mm 1 x 10 PSA"

Also, I called psa when I was originally working on this and they sent me a return label.  I got the 147's to work and never bothered sending it back in.