Barrel fitting

[Tom]

Hi
I'm fooling with an old DH fitting a set of VH barrels to it. I am new to shotguns and am trying to learn as much as I can.
I have been reading as much as I can on the subject. I keep reading the gun is tight or the gun is loose in different for sale adds. I think I have this sorted out but am looking for some clarification.
Loose means the lugs fitting loose in the receiver ?
Off face means the barrels are to far forward and there is a gap in the breach ?

Could someone confirm my thinking here ?

I was fortunate that my barrel lugs were to wide and did not fit into the receiver, I spent hours working them down to accomplish a nice tight smooth fit.

Last question, if they were loose in the receiver how can they be tightened up ?
I figured out how to tighten up the off face gap, but I haven't figured out what I would have done if the lugs were loose in the receiver .

Any info greatly appreciated Thanks, Tom