Mag question

[NebSig]

Hey there, I have been thinking too much lately. Has someone tried anything like a 40 or 60 round mag with 6.5 grendel? I got to thinking, if it works with quad stack 556, what's to prevent it from working with triple 6.5? Somehow, it seems like this is the solution to the polymer mag issue also. No need to get double stack all the way up if you can slightly alternate and get triple below, right?
Fat bottom with narrow top and still able to support and then adjust length for desired capacity...
Just thinking out loud and wanted to send it by people with much more experience in these areas.

[FLshooter]

I shoot bench or prone @ targets.I never felt a need to go bigger than a 10 rd ASC mag for my Grendel Or a 20 rd Pmag for my 223 platforms.It has a lot to do with what you are using the rifle for.

[A5BLASTER]

Look for the amend2 mag thread or build on a set of six8 recivers and use their magpul six8 mags.