...it might be possible to design and create using a computer and a 3D printer a higher capacity magazine than the sad excuse for a mag that comes with the M77.  I knew that when I bought it that magazines would be a major pain in the rear to find for it.  I'm not going to try to modify M14 mags as there is a company, CS Specs that supposedly will be releasing a 20 round magazine for the M77 soon, possibly by January. But in the mean time I've seen some articles online about 3D-printed AK47 magazines so I know there is potential out there.  I've got a feeling that CS Specs is sitting on a potential gold mine being one of the few, if only sources out there offering M77 mags for sale.

So you don't want to modify M14 mags because CS Specs will be releasing some soon, but you want to go through the trouble of having someone do all of the R&D to design and 3D print a mag instead? Seems like you've got it backwards, man. Modifying M14 mags takes a hell of a lot less time to do and will be immensely stronger than something printed out.

PSA:
To ANYONE converting m14 mags, Please use CMI made mags not  Vintage VN era mags.
Check Mate Industries (C.M.I.) Mags are current USGI mags and work just as good as older GI mags, and they are only $25
Vintage USGI mags havent been made in a long time and are collectable to alot of folks.
Thanks