area51guy said:
I just bought a Ruger Mk 4 22/45 Lite pistol. Using what I consider to be "good" ammunition (Remington, Winchester, CCI) it is experiencing way too many failure to feed and failure to extract jams. Also getting some failure to fire issues. I have gone thru the mags and cleaned/polished all the internal parts so they operate smoothly. Any other suggestions?
Well, I sure do NOT agree that you have done all that YOU, as the owner can do about getting your Mark IV pistol to co-operate like you want it to. If you do send that pistol back to Ruger, they are only going to replace parts with the same parts they have in stock. Will there be much improvement? My educated and experience says, "No".
My recommendation for all ~NEW~ Ruger Mark pistols as purchased, is to run CCI Mini-Mags, or another .22 rimfire round that has close to the same velocity as the Mini-Mags, through your new pistol. All of the springs in your new pistol need to be exercised until they reach the working set where they were designed to operate fully and properly. How many rounds does that entail? There is no specific number that can reliably be depended upon, but after you run several hundred hi-velocity rounds through your new pistol, then try some of the standard velocity rounds that run at around 1200 FPS, and if those feed and cycle properly, then you are there.
With the Ruger Mark IV, Ruger has chosen to continue with the stamped steel extractor they've been using since 1949. There's a damn good reason why there are at least 7 various manufacturers of aftermarket extractors for these pistols and rifles. I have tried each and every one of the aftermarket extractors that are currently available and have settled on the best one that I have found that works superbly in all the Ruger Mark pistols and the 10/22 rifles. The cost of this much better extractor is less than a "pack of chewing gum" and will have your spent cases literally flying out of even the dirtiest of chambers.
So, try some CCI Mini-Mags in your new pistol, tune and smooth your magazines, and look for a much better extractor and I guarantee function will have you impressed in short order.