Colt AR15 5.56 Grey blank 5/20 mag with pics now

[IDPACONVERT]

I've seen pics of the red blank mags, but cannot find any information regarding the Grey aluminum mags with the short 5.56 blank follower, and partition/block for the shorter blank rounds.
Anyone have any information regarding this mag?
It looks like the red mag, but it's milspec grey.

http://i1354.photobucket.com/albums/q686/lessspeedy/20150922_223729_resized_zpsqqovpbja.jpg
http://i1354.photobucket.com/albums/q686/lessspeedy/20150922_223802_resized_zpsjuk3oyzu.jpg
http://i1354.photobucket.com/albums/q686/lessspeedy/20150922_223646_resized_zpsjqdm0thq.jpg

 

[#1bcshooter]

I've shot military & movie blanks in standard AR mag's & never had any problems .

 

[ChrisAlston]

I've also fired many many military blanks using the standard mags. I never even knew there was a special blank mag.

 

[gadget]

Made in the 1960's extremely rare & collectable, never seen a grey one / have seen the red one though

http://www.billricca.com/collectors_corner.htm

gadget

 

[IDPACONVERT]

Thanks for that information Gadget, I've seen the pics of the red mags, but couldn't find any info on the Grey mag.
It looks to be a factory made mag, just like the pic of the red one.