I bought a PSA AR-9 16" upper and put it on a Spikes lower (Colt mags) with a generic milspec LPK/FCG. Will skip some drama but the bolt was faulty, big hole drilled around the firing pin allowing primers to blow out into the bolt face. PSA replaced bolt. New bolt would not run, had to open feed ramp to accept new bolt. Kind of frustrated with PSA QA at this point.
With that work done the gun ran. But after 3 mags I started reliably getting doubles, but only in the last 15 rounds of a 32-round mag. Which implies increased bolt speed may have been a factor. Lower passes all function tests for disconnector function and spring installation. Had AR-10 spring and 7oz Spikes buffer installed while doubling. Brass throw distance was short so thought possibly not getting enough bolt travel to reliably reset the disconnect. Subsequently swapped a standard AR-15 carbine spring with the AR-10 spring and ran 15 rounds with zero malfunctions.
More testing will tell the story, but interested in any experience optimizing AR-9 function. These are reloads, middle-of-the-road 9mm book loads with Unique. Thought the PSA appears to be short throated as the lead bullets are making contact when chambering (kinetic pulling of 1 bullet when ejecting unfired round). These are loaded well within SAAMI specs and run fine in multiple other 9mms. Did I voice my frustration with PSA specs??
With that work done the gun ran. But after 3 mags I started reliably getting doubles, but only in the last 15 rounds of a 32-round mag. Which implies increased bolt speed may have been a factor. Lower passes all function tests for disconnector function and spring installation. Had AR-10 spring and 7oz Spikes buffer installed while doubling. Brass throw distance was short so thought possibly not getting enough bolt travel to reliably reset the disconnect. Subsequently swapped a standard AR-15 carbine spring with the AR-10 spring and ran 15 rounds with zero malfunctions.
More testing will tell the story, but interested in any experience optimizing AR-9 function. These are reloads, middle-of-the-road 9mm book loads with Unique. Thought the PSA appears to be short throated as the lead bullets are making contact when chambering (kinetic pulling of 1 bullet when ejecting unfired round). These are loaded well within SAAMI specs and run fine in multiple other 9mms. Did I voice my frustration with PSA specs??
