I swapped out the 10# factory recoil spring in the Specialist for 12# Wolff and hit the range with some 124 grain AE and 147 grain HST. First up was the AE and had a FTF on the second round using Wilson Vickers mag. The gun cycled another 58 rounds of AE and 50 rounds of the HST (110 total today) without failure using a variety of mags including DW factory, Wilson ETM, and Tripp Cobra. Perhaps it was just the spring getting broken-in. The Guardian cycled another 50 rounds of 124 grain AE without malfunction.
That puts the round counts at:
Specialist - 830 rounds
-660 with 124 grain AE
-50 with 124 grain Lawman
-120 with 147 grain HST
-Malfunctions to date: FTF 1; FTE 1 during 10-8 extractor test, 0 during regular fire.
-New 12# recoil spring at 720 rounds
Guardian - 250
-250 with 124 grain AE
-Malfunctions to date: FTF 0; FTE 0; passed 10-8 extractor test on first try