I'm with Dean, looks like .410 tubes. 28 gauge tubes in a 20 gauge chamber are so thin as to be fragile. Not these. Be very careful getting those tubes out of there. Your gun is very valuable and not hard to damage. Tell us where you are located and we'll recommend a talented gunsmith. They look like Savage tubes except that the Savage tubes are longer than three inches and the extractors are usually a little smaller than your extractors. Are you sure your tubes are only three inches long?
|