[Rangegod]

I put another 175 rounds (320 total) through my PSA 10.5”, 9 mm AR yesterday with zero issues. After my initial testing, I installed the Kaw Vally 7.5 oz. 9 mm length buffer and their extra power PCC/.308 buffer spring. This combination makes for very smooth operation by, slowing the action to increase dwell time and preventing violent ejection, while reducing bolt over travel to prevent damage to the bolt stop catch.

During the week since my initial post I have seen several comments from this, and other forum members and continued to research many online reviews. There seems to be a common theme to most of the problems encountered. This can basically be stated as “tolerance/clearance” problems.

Due to all the various upper, lowers and 9 mm bolts available on the market, there are literally hundreds of possible combinations of parts. This makes some tolerance conflict between parts inevitable. Most of these issues can be identified and/or resolved by following the manufactures instructions to test mag fit on closed bolt and checking (and maybe correcting) bolt/feed lip clearance on the closing bolt before installing the conversion kit. Instead I watched one on line reviewer prove Einstein’s definition of insanity by destroying three mags in succession, while expecting different results.

As to the plastic ejector, after 320 rounds (over 200 on one mag) I can see no signs of any ware. This was a surprise and force me to think about the engineering (something I don’t do much of since retirement). The ejector’s sole purpose is to initiate the pivot of the case off the extractor hook. This change in force vector and the velocity imparted by the bolt throws the case clear of the action. Although it is counter-intuitive, the ejector is in reality a relatively low stressed component. The amount of force require to initiate the case pivot off the extractor is minuscule and applied for only a millisecond. In addition, the mass of an empty 9 mm case striking the ejector is very low. This makes damage to the ejector during normal operation of little concern. Damage by tolerance conflict is another issue as discussed previously.