The gun I just received last week is a 581 prefix gun. It is a stainless ranch rifle #5817 and the brand new Tapco 20 round magazines I bought are too tight to function in it. The Mags are snug when inserting unloaded and when you have them loaded they swell slightly and are harder to insert into the rifle. They then won't let the remaining rounds in the magazine rise to be picked up for the next shot. When I pull the magazine out , Yes I said pull , because they won't drop, the rounds are able to rise like they should. You also can't insert the magazine into the rifle unless the bolt is locked open. Once I decided to send them back to Midway I decided to just throw them in the corner for now because by the time I separated out the shipping fees I would have had what amounted to 1/2 the cost of one magazine actually back in my pocket. I will be contacting Tapco and seeing how good their lifetime warranty is.
