ACTUAL CONFIRMATION if CZ-527 7.62x39 Mags work for 300-221 rounds?

[amafrank]

I personally have slotted mags for the 527 .223 mags in order to get them to feed 300-221. I've not tried cutting down the follower for an extra round though so I can't make any comments on that. I looked all over for a 7.62X39 mag to try but never could get my hands on one so no help there either. I can see that the width of the 7.62 mag along with a feedlip issue may make them not work with the 300. The 7.62 is wider and the feedlips may not hold the smaller round ????

Frank