rogertherelic said
Check Rock Island Auction on Apr. 13th. lot #649.  The description and fifth photo on line, shows the barrel caliber stamp and the receiver is grooved.  The serial number 179525 should be to early, as the Schwing Book says about #225,000 was when the receiver change took place.  Am I seeing things?

RDB  

That is definitely way too early for a grooved receiver top gun.   The change actually occurred around SN 215000 or about 10,000 rifles earlier than Schwing notes.  One other odd thing is that the barrel has almost NO slide wear on either side of it.  This rifle must have never been used/racked since 1952!!   I kind of doubt it.

Michael