P93 is almost impossible to find of the "p" series, I found a like new in the case one about a year ago, it is the only one i have ever seen. The P91 is almost as hard and all the others are getting few and far between too.
I have shot my LCP II with LCP and LCP II magazines and it has always run flawlessly with both types of mags, only difference is the LCP mags will not lock the slide open. Yours definitely needs to go back for some sort of repair.
The fit on everything on my bronze Wrangler is as good as any of my Single Sixes. At 15 yards I have found it to shoot as well as my Single Six with same barrel length, I tried 6 rounds of 21 different types and brands of ammo that I had on hand in both guns and the Wrangler shot tighter groups...
I have one I bought used 14 months ago, it is vary accurate and pleasant to shoot, bought it for a companion to my CZ 455 am glad I did. Can't think of anything to look out for with a used Ruger, never have had an issue with a used Ruger firearm.
Found a 4 inch Speed Six made in 1974 last November, a 4 inch Service Six made in 1976 in January and a 4 inch Security Six made in 1982 in April. All three are blued and look to have been shot vary little, have been looking for a Six for over ten years and these three are the only ones I have...
Picked up a Service Six last Wednesday at local gun store, is jest like that one except it has the standard grips, was also made in 1976. Last November I found a blued Speed Six with 4 inch barrel made in 1974 at same store, Only 2 Sixes I have seen in gun shops in the last 20 years. The Six...
I have a P345 for 7 years that was made in 2005 and to me it is the best of the P series pistols, it has fired many rounds and has never had a fail to feed or fail to fire issue. It is comfortable and pleasant to shoot and for me is more accurate than my P90 or P97.
They are getting really hard to find, I found a stainless Speed Six with 4 inch barrel at gun shop last month, only Six series I have seen anywhere in last 20 years.
Picked up a P-85 stainless at LGS 10 days ago for $289.95, pistol and original case looked like new with no scratches or signs of wear, came with 2 original mags that also showed no sign of wear or use.
My manual lists 3.5 to 5.5 gr. of Bullseye, you might try a heavier load, sounds like the slide is not traveling quite far enough back to give it enough momentum to close. Kind of like when you ride the slide down instead of slingshotting it.