Two more cents thrown in for the Volquartsen trigger kit. I'm not sure how "epidemic" the problem is but my research on the Mk IV turned up a lot of comments about how bad the triggers are. This was after I bought a Mk IV 6" Standard, which definitely had a horrible trigger - l-o-n-g, heavy with lots of creep.
But a Volquartsen kit turned it into a beautifully light trigger with minimal take up and overtravel and a consistent 2 1/4 lb pull; and it does eliminate the magazine disconnect. They're kind of spendy as a percentage of the purchase price of the gun and the idea of installing one yourself can be daunting but there are at least two excellent youtube videos that explain it step by step including gotchas to watch out for. Took me about 25 minutes to install, going slowly and referring back to the videos for each step.
Rugers are accurate and generally very reliable to begin with, and while there are a boatload of after market gimmicks and googaws, some worthy and some just useless window dressing, IMO that Volquartsen kit is the single best thing you can do to really upgrade a MK IV.
