I own 2 S&W model 1000 (2-3/4") and 1 model 1000M (3").... unaware that they also mfg. a 1000 Super 12 (3") I just bought a barrel stamped Super 3" thinking it would fit and work on my 1000M receiver. Well to my surprise the magazine lug is located about an inch different than either the std. or mag barrels and prevents the forearm from going on! Is there an inexpensive fix for this or is the Super 3" barrel simply designed to only fit Super 12 receivers? Also can anyone explain what is different (other than barrel fit) between the 1000M and 1000 Super 12. Many thanks for any info!

I had a Super way back when. The difference between the two models is the Super has a self-regulating gas system which allows one to shoot all commonly found 2 3/4"-3" shells (1 oz Win Xtra-Lite to 1 7/8 oz magnums) interchangeably with no adjustment.

The 1000M models had a different gas system in which the size and/or number of gas ports determined the amount of gas siphoned off to operate the action. That is why the 3" versions do not work well with lighter shells as there is not enough gas available to meet the performance criteria.

The fix is to sell your current barrel and purchase a new one.

Thank you very much for the education, I don`t believe you could have explained it any better or clearer than that! After reading what you said it certainly makes perfect sense! 1 of the standards is a slug barrel, one came with a 28" fixed modified and the M had a 30" full...I bought a 28" standard with thin wall aftermarket screw in chokes installed! Again not knowing they made a "Super 12" I got excited when I seen 3" with factory screw in chokes and 28" length to swap with the 30" full. Once again thank you for sharing your knowledge!