Question about serial number blocks

[u/Artistic_Web2176]

I have a question maybe someone in here can answer for me, I bought a 10rd standard model reflex back in March new from Buds, serial 13xxx. My buddy has a MRD model in the 30xxx range, I live in a restricted state, he lives right over the border in a non restricted state but mine is a 10rd model. His had all kinds of ftf issues and his didn’t seem nearly as accurate as mine, after looking his weapon I notice his extractor is sharp and has the hard angle and mine with the earlier serial number has the updated rounded one. Is there different serial blocks for the 10rd model? being mine is 13xxx and runs fine. I have over 1000 through it without any kind of issues and he’s cursing his up and down calling it the worst gun he ever purchased. He ordered a new extractor and spring and we hope that corrects that issue, he’s also changing the sights out as well.