Which caliber 870 do I have?

[Jerry]

Hi there...

I have an 870 that my dad gave me in 1966 (I think).. Early on due to work circumstances (it's a long story) I lost the barrel. I just had the receiver refinished as I want to pass it onto my son.. I remembered it being a 20 gauge. Took it to Gander Mtn and they are sure it's a 16 gauge (first they thought it was a 12 gauge). Neither the 12 or 20 barrels they had fit on it.
The serial number on the receiver is 894909x.
Before I spend $230 on a barrel that may or may not fit can someone give me clarity on this?

The stock and receiver look absolutely beautiful.. I don't want to screw this up..

Thanks so much..

Jerry

[Synchronizor]

That's a 20ga serial number, but it's one of the older large-frame 20ga guns, from back when 12, 16, & 20ga 870s were all built on the same receiver size. That's why the new 20ga barrels you tried didn't fit; they were meant for the current 20ga models that use the same small receiver size as 28ga & .410 870s.

[Trapguy]

Probably the most expensive replacement barrel. I had to buy another gun to get the barrel I wanted

[Scorpion8]

Probably the most expensive replacement barrel. I had to buy another gun to get the barrel I wanted.

Ah, but you can sell the receiver/stock portion to recoup some of your cost. Glad you found the barrel.