Love my Gen 3 Glock 30 so much (hundreds of rounds without a single malfuction) that I just picked up another Gen 3 NIB. Upon field stripping it I see that the recoil spring assembly now has a metal sleeve on half of the assembly which my other doesn't have. Is this an alleged improvement? I've not gotten to the range with it yet but can't imagine it being more reliable than my other G30. When was the change made? Did a search but couldn't find answers.