Action bar tube on an 11-87 cracked or not??

[Songdog2012]

I pulled my 11-87 apart and noticed the tube that is part of the action bar assembly appeared to be craked slightly on the flat spot that rests against the action bar i popped the tube off and apon further inspection it just appears to be a milling issue where they milled it flat but ate into the inner diameter of the tube there are no rough spots only what looks like a crack, has anyone else ever seen this? I dont see where there should be any ammount of stress at this particular spot to cause a crack!