Rifle Scabbard

im delving into a project that i want to make a Rifle Scabbard to put on my back so i can carry two rifles onto the feild. I was thinking on making the Scabbard myself but i think it would be a helluva lot easier if i could buy one. I want it so(if they're already in production) i can use my G36 for close and medium shots then have the M14 on my back for those long shots in the scabbard on my back and then i can pull the gun from my back over my head and use it and easily put it back. what i was thinking is taking a OD cloth MOLLE gun case and cutting the top off and strapping it to my MOLLE straps on the back of the vest to hold it there and then use a velcro strap or a buckel to secure the gun to the scabbard. i just want to make it and i wanted to get some input, ideas, or possibly a site where they sell em. HELP ME OUT GUYS!!!