I have on the the Bushmaster 10rd. post-ban mags. I look at it, it seems the same dimensionally to my "I survived the 'nam" USGI 20rder (which still functions just fine).
I was wondering if it's possible to convert them to a 20 rd. no-ban mag come tommorrow?
Nope. Sorry dude.
The 10 round Bushmasters: "Can not be disassembled without causing damage" as stated per XM15 E2S Bushmaster poster.
With the ban going bye-bye, I don't see any point in screwing around with modifying mags. The cost of rebuilding a mag will run you the same as a new one when you add in the cost of your time.