Well here is what I found on the mag tube.
The mag tube is screwed into the reciever and sealed with locktight. I tried twisting it and even with my herculean effort, it wouldn't budge.
Some guys on another forum suggested to put the gun in a vise (obviously after padding it) and use a wrench to turn the tube and break the seal, and that once the seal broke you could hand turn it from then on. I am not sure that I want to try that just yet. I can shove the 8th round in as far as that arm that loads rounds from the tube, so I pushed it in that far and am letting it sit there for awhile.
As far as upgraded followers are concerned, I saw where it was pointed out that the beefier follower reduced the mag capacity by one, which would defeat my purpose.