I'm having almost the same problem with my new SS226. (only 1 mag shot so far.)
Symptoms:
Fires full auto with a prolonged trigger squeeze.
After between 5 and 10 rounds the hammer will not lock back. The slide will strip a BB into the chamber but not lock the hammer. At this point gas will sometimes continue to vent.
On the first 2-3 times I squeeze the trigger a liquid is being propelled out along with the gas from the breech/slide area.
Diagnostics done so far:
Racking the slide reveals a spot about 1/3rd of the way through the slide's forward motion where it has a significantly higher amount of resistance.
The very top corner of the hammer when fully cocked has been worn to bare metal.
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Hammer has 2-3mm of play when fully cocked.
Lubricating the hammer and the slide with only a field strip has not helped. See below, disassembly of hammer with massive amounts of lubrication has provided improvement. Duration and quality of improvement remains to be seen.
My initial thoughts:
The play in the hammer is causing it to sit higher then it should when fully cocked and it is rubbing on the slide preventing full slide travel.
How can I correct this?