Subsonic 9mm Load Results

I got a chance to take those initial 9mm rounds out to the range and I have to admit that it was a lot of fun!  I only had 50 rounds; but, it was one of those times where I left with a smile on my face.

The initial testing was done with a 5″ M&P and an XD(m) 3.8 with a Storm Lake threaded barrel.  An AAC Ti-RANT 9 suppressor was also used with a sound level meter to get some suppressed results.

Having said all that, here are the results:

M&P 9 Velocities

  • Min =  862 fps
  • Max = 886 fps
  • Avg = 874 fps

M&P 9 Sound Levels (Unsuppressed)

  • Min  = 161.1 dB
  • Max = 164.7 dB
  • Avg = 162.42 dB

On the M&P 9, this load was easily in the subsonic range – yet it is still above the threshold for making Minor at IDPA & IPSC matches.  As usual I was amazed at just how loud an unsuppressed weapon really is – even when shooting subsonic ammo.

After the sound level meter & chronograph, I only had 10 rounds left to test for accuracy in this pistol - and it just wasn’t enough to get a good idea of how this load will do.  I fired a single 10-round group from an unsupported, standing position @ 15 yards. Unfortunately, the grouping wasn’t that great; but, I just didn’t have enough ammo to see if it was the load, or the fact that I hadn’t warmed up yet…

MP 247x300 Subsonic 9mm Load Results

10 round group fired from an M&P with a 5" barrel.

XD(m) 3.8 Velocities

  • Min Unsuppressed = 844 fps
  • Max Unsuppressed = 885 fps
  • Avg Unsuppressed = 861 fps
  • Min Suppressed= 861 fps
  • Max Suppressed = 916 fps
  • Avg Suppressed = 892 fps

 

XD(m) 3.8 Sound Levels (Unsupressed)

  • Min = 162.2 dB
  • Max = 163.4 dB
  • Avg = 162.81 dB

XD(m) 3.8 Sound Levels (Suppressed using Ti-RANT 9)

  • Min = 123.8 dB
  • Max = 128.6 dB
  • Avg = 126.09 dB

Once again, this load was easily in the subsonic range – even when shooting with the Ti-RANT, which added 31 fps to the average velocity.  With this pistol, we are actually a bit below the Minor threshold for IDPA & IPSC with the slower rounds.

As always, the Ti-RANT was just amazing – bringing the overall sound measurements down into the mid-120′s!

As with the M&P, I only had 10 rounds left for accuracy testing; and, although the XD(m) did better than the M&P, I’m still hoping for better accuracy results in the future.

XDM 247x300 Subsonic 9mm Load Results

10 round group fired from an XD(m) 3.8 with a threaded barrel

Overall, I had a lot of fun with this load. Now I’m going into mass-production mode and I’ll start running it through it’s paces in the next few weeks. My one unresolved issue is the accuracy – since I really would like to get the same accuracy I see with my 124gr loads. I’ll post if that ends up being a problem once I can get more than one 10-round group from each pistol.

Posted November 14, 2011