this is the lower i used for my ar45
CNCGUNSMITHING - www.cncguns.com - AR45
after doing a little digging i found some grease gun mags that look like thy're still in stock
Search | Numrich Gun Parts
i bought 10 from here back in 2011 still wrapped up in paper and some cosmo on em. after cooking em they all run flawlessly.
they were a little cheaper $32 in the wrap back then to