Rem 20ga 870 LW

[bull]

Can anyone tell me what the difference is between a standard and a lightweight (LW) marked 20 ga barrel.  I just obtained a new 20 ga 870 with slug barrel. Was looking for a field barrel to go along with it. I found one on an auction site that is marked 20ga LW 2 3/4 - 3".  Anyone know if this will fit. I'm getting all confused with these fancy offshoots from a basic shotgun, Sporting Clays, Lightweight, Special Purpose, etc.   I heard or read somewhere that the difference was between the old 20ga 870s built on a 12ga receiver vs the newer guns built on a 20ga specific receiver. Is this the difference?

[RobW.]

Being LW isn't the problem.  Early 20's with fixed choke barrels had a standard size 12 ga barrel band on them.  When they started putting Rem Chokes on the 20 barrels they changed the magazine size as well to be specific for a 20 so the barrel band was also changed and made smaller.  So when getting barrels for a 870 20ga. you need to make sure of the barrel band.  THe older ones were the same size as a 12 ga. and if you have an old 870 20 ga. that had a fixed choke barrel then the newer RC barrels probably will not fit the magazine tube. 

[Couger]

Can anyone tell me what the difference is between a standard and a lightweight (LW) marked 20 ga barrel.  I just obtained a new 20 ga 870 with slug barrel. Was looking for a field barrel to go along with it. I found one on an auction site that is marked 20ga LW 2 3/4 - 3".  Anyone know if this will fit. I'm getting all confused with these fancy offshoots from a basic shotgun, Sporting Clays, Lightweight, Special Purpose, etc.   I heard or read somewhere that the difference was between the old 20ga 870s built on a 12ga receiver vs the newer guns built on a 20ga specific receiver. Is this the difference?

Lightweight 20 gauge?  I would bet that barrel would fit your gun just fine, but is the seller in a locale where he can let you examine that barrel and try it on your new gun?
 
Before 1974 approximately, whenever Remington made a M870 in 12, 16 or 20 gauge, all those shotguns were made with the same size of action (externally). Remington would use the same size of billit steel to machine an action/receiver during manufacturing.
 
But it was around 1974 is when Remington finally offered their 20ga pumpguns (and 28ga and .410's) in a scaled down (and lighter weight) shotgun!
 
Winchester on the other hand has NEVER offered their M1200, M1300, or M120 Ranger in 28 or .410, and even their 20gaggs have ALWAYS had (externally) actions as bulky and big as 12 gaggers.
 
But on a 20ga LtWt M870, if you could compare one to a 20ga M870 'STANDARD' would quickly show you the LtWt gun is slimmer, skinny-er (thibkness) through the reveiver, and would weight considerable less.  A barrel for a ltwt gun would not fit on a standard gun if you tried it, nor visa versa.