MANY POSTERS HAVE MENTIONED LIGHT PRIMER HITS.
I took the SR9c gun apart when new, sprayed it a lot with Birchwood-Casey non-flammable Gun Scrubber, installed GHOST Ultimate 3.5# trigger, lightly polished the rails, slide and anything that looked critical, took apart and removed the magazine disconnect as per Josh Hearne,
degunked and cleaned and oiled the inside of the striker "tunnel". Reassembled without the mainspring, oiled sliding surfaces and racked it back and forth by hand 300 times. Put in mainspring and cycled and dry-fired 300 times.
Then, I took it to the range and fired it 217 times (ran out of time and ammo) with mixed ammo, primarily Win White Box, some CorBon JHP.
It ran like a top; no burps or failures to feed or eject. Very accurate; ten shots in one inch from a quickly improvised rest at the range. No recoil problems of any kind.
I still have a thumb safety that is hanging up on the slide so difficult to engage, and the slide serrations are much too sharp for comfort.
Next time, I would buy the Ghost Rocket to get rid of overtravel.
I had read in this forum about so many problems that I thought I would overdo the preliminaries. It was well worth it to me. I used leather glove to do the slingshot so many times to keep meat on my fingers.
This is my estimate of my gun.
From what I've read from many posters about light primer hits, I'm guessing that the biggest culprit is the striker tunnel. Dissassemble it as per J. Hearne's instructions at this link: Follow instructions in the section to remove Mag disconnect.
http://www.rugerforum.com/phpBB/viewtopic.php?t=52057
Sonnytoo