Ok, I had a really nice day this morning at the range. I just wanted to share the results of my ammo tests for other XD9 users out there. This is not a definitive test so I welcome other shooters to test it to confirm and compare results.
How I tested:
1. Set up the target 25 yards down range. Target is an 8" round target in a 12" square target. Scoring is determined by counting how many shots were in the black 8" round target and how many were in the 12" square target.

2. Shot a box each of 4 different ammos, 5 rounds (or 1 mag) at a time. Shot 5 of the CCI, then 5 of the Federal, then 5 of the Winchester, then 5 of the Gold Dot, then back again. I counted the number of holes in the 8" and 12" after every 5 bullets. Another option was to shoot all 50 bullets at one time per box but I wanted to avoid the effects of practice and fatigue. So I staggered the ammo types and did it this way.

Testing Results:
1. CCI Blazer 9mm 115gr FMJ
- in 8" round target: 18/45 (40%)
- in 12" square target: 30/45 (67%)
2. Federal Ammunition 9mm 115gr FMJ
- in 8" round target: 21/45 (47%)
- in 12" square target: 31/45 (69%)
3. Winchester Bulk Ammo 9mm 115gr FMJ (came in box of 100. Took 50 to the range.)
- in 8" round target: 30/45 (67%)
- in 12" square target: 41/45 (91%)
4. Speer Gold Dot 9mm 124gr JHP (small box of 20)
- in 8" round target: 10/20 (50%)
- in 12" square target: 17/20 (85%)
Anyway, there you go. At least for me, of the 4 ammo i tried, the Winchester 9mm 115gr bulk ammo worked best on my XD9.
Oh yeah, I forgot to mention that I've had no jams or failures on any of the ammo I've used. Probably fired around 600-800 rounds through the gun, which is cleaned after every visit to the range. Pretty happy with the XD9 as is.
