This has been a hot topic on the Ruger forum for a couple of weeks.

I recently acquired a Mk4 Target and like many others, I have installed the Volquartsen triger, hammer sear, et al. That upgrade makes the gun much better than it came from the factory, and so far there have been no reports of safety operation-related misfire events with such modified guns. My Mk4 does not exhibit the defect after the VQ components were installed.

Regardless of my inability to duplicate the defect, I will strip out my Volquartsen parts and ship back to them my vacant lower assembly along with a baggie of the original Ruger trigger parts. Upon its return I will re-install the VQ parts and I will save the upgraded Ruger parts for some future owner of my gun that may not be aware of the safety defect and for reasons unknown at that time may want to return the Mk4 to its original configuration. I think that's the responsible thing to do. And besides, it'll get me another magazine.

Hopefully the VQ parts will be compatible with the upgraded safety lever(s). Consensus from the RF are that the original sear and disconnect lever are main culprits, which will soon be replaced (on mine) with the VQ parts that I'll removed prior to the MK4's return. With the powers vested in me by Youtube, installing the VQ trigger assembly is well within my mechanical abilities.

I commend Ruger for their open, honest customer service in addressing this defect. -S2