I have an uncle that used a dry lube on the friction rings on his A5. The same dry moly for locks from ace hardeware. He also used pencil lead he would sharpen the pencil and rube the mag tube with it. Not sure if this is proper but he would not use anything else on it. BTW never seen it jam miss feed or anything else, and he seldom missed.
Right or wrong it worked for him.
The chamber on my 11-87 has to be spotless or it will not extract fired hulls. Ribbed shells work best in it. I may have other problems with it causing this problem. I replaced the o-ring which didn't fix it (helped a little). Maybe shotgun shells are just to cheaply made now days.