Well today I finally got to test the reliability of the Gen3 G32 barrel in my Gen4 G23.
First up was 200 rounds of WWB 125gr FMJ. As expected, the gun ran flawlessly. All rounds fed fine and ejected strong at 4-o'clock with the exception of 2 BTF (when I had gloves on). Next on the agenda was the hyped Underwood 125gr GDHP. I will admit my hopes were high with this load and I expected them to run just as well, and possibly be a new carry option. I was sorely disappointed.
I ran 50 rounds thru the gun and the second round down range was a light strike. I have 1800 rounds thru this gun (1150x .40/500x 9mm/200x .357) and I've never had a light strike or bad round. I inspected the primer and found that it was in fact a light strike because A) the round fired after a second strike, and B) the first strike's dimple was round and shallow, while the second strike was typical Glock rectangle and deep, and the round went off. There were a total of 4 subsequent light strikes throughout the 50rd box. These results are totally unacceptable in carry ammo. It's dissapointing because of 2 reasons. First, the Underwood is readily available and CHEAP in comparison to other SD loads. At around $30/50, it's the same price as Walmart WWB FMJ, and would allow for more affordable practice with the same round I'd carry. Second, the recoil really isn't that bad compared to the .40. It's hard but less flippy. I still have 100 rounds of the Underwood, which will now be limited to range use only. I will probably try some Winchester PDX-1 next, as it is the ammo I carry in my G23 and M&P Shield, G26, and G21.
Overall I felt the Gen4 G23 handled the .357 load very well, and I am sold on the Gen4 RSA helping tame recoil over the Gen3 springs. Next time I get to the range, I will be running another 200 rounds of WWB and hopefully, 20-40 rounds of PDX-1 (at $1+ per round, OUCH). But the consensus so far is: Gen3 barrels in Gen4 guns work! 500 of 9mm and 250 of .357 so far. Stay tuned!