Want to build GM Hydramatic m16 clone. Help!

[old tanker]

When I was a drill sergeant at Fort Campbell in 1971-1972. Our company had M16A1 rifles from all three manufacturers, Colt, H&R and GM-Hydramatic, with most being GM. When issuing the rifles to each incoming cycle of trainees we made a concerted effort to ensure all the left handed shooters were issued Colts. Our observation then was that the Colts tended to eject brass pretty much straight out the side. The H&R seemed to have no discernible tendency while the Hydramatics very much toward the rear. On the ranges we always put all the left handed shooters together on the left end of the firing line. A trainee with hot brass down his shirt and a loaded rifle in his hands could generate more excitement than you wanted. Along about this time PS MAGAZINE, the Army's Preventative Maintenance "comic book" actually "advertised" a plastic brass deflector that snapped into the hole in the charging handle and advised "southpaws" how to get one through the Training Aids Support Office or "TASO" or by the Training Audiovisual Service Center or "TASC."

You can see in the picture that it is plainly marked "TASO-FJSC," having been produced by the Training Aids Support Office, Fort Jackson, South Carolina