I have a MP 15r that shoots a 5.45x39 and love the cheap ammo but hate my mag situation. I am pretty much stuck using C Products stainless steel mags. I would really love if someone made a polymer magazine for this round. Does anyone know of a modification you can make, to make 5.56 polymer mag work for a 5.45 or any other options?

Wrong forum. This is the 15-22 forum.

Yup ... wrong spot and I wouldn't call 5.45X39 exactly cheap

Sorry, new to the forum. Did not realized this was restricted to 22. Should have looked closer. Yeah, well 5.45 ammo is not as cheap a 22 rimfire but it's a heck of allot cheaper than 5.56. I got a local place I can get old military surplus ammo for $120 for 1080 rounds. Just have to give it a nice thorough cleaning afterwards.