I need to get heavier ammo. My gun has yet to lock open on an empty mag. Today, I got multiple failures to feed with WWB 115 grainers. I think the slide is short-stroking or something. The spring tension has loosened up nicely up to the point where the striker will reset and a round will extract. However, it is still a chore to rack it all the way back. That, or the goddamn magazine springs are still so strong that it's flinging my ammo into the top of the locking block instead of into the chamber. But if the magazine springs are so strong, why isn't the slide being held open? It's gotta be a combination of things. I almost want to have someone else shoot my gun so I know it's not just me.
That said, the trigger has broken in quite nicely. Takeup is nice and smooth and if you shoot off the reset it's a buttery scary-light trigger. I shot another 375 rounds at the range today and was all over the place. I had a lot of difficulty with my hand placement and was shooting greatly to the right. Precision was pretty decent, however. I wish the 509 came with the large backstrap instead of the small one. In the FTF pic above, my right index finger is actually over the trigger guard. I feel like my left hand is taking up so much space on the gun that I can't get an equal force onto the pistol with my right hand. So all my shots are pushing to the right as a lefty.
Here are my first few groups. 15 rounds each at approximately 60-70 rounds per minute, all at 5m, except for the head which had to be 10m, and was shot at a slower pace so I could try to see where I was hitting. First group is center-chest, then center-abdomen, then right shoulder and finally left shoulder. As you can see, the first group was grossly down and right but tightened up nicely upon reaching the left shoulder.
The next round below are groups of 10 at 7m (10m head)-- what I can reasonably speed-load into my mags with the cam loader. Same story, right chest, then left chest/axilla, followed by the left elbow "3", and then the left "4". Not bad.
My last 100 rounds were where most of the failures began. The gun stopped going into battery and had to be tapped home a lot. It's was pretty bad. I don't really want to use 115gr again until I try shooting a few hundred rounds of some heavier stuff.
I've had that mixed up a time or two before, but I'm originally from a Non-English speaking country, so that's my excuse. 
Blasphemy! Thats something far better and even older than that crude dime-a-dozen Russian boomstick, its a Peruvian Mauser 1891 with the 1889 system. Or in other words, pure German quality, craftsmanship of bygone times and a sprinkle of divine magic wrought into an artifact of wood and steel. 
