I have collected, researched, and shot Winchester model 12's for more decades than I care to admit. Some misimformation exists and has been repeated here, and I will try to clear up these misunderstandings. First all model 12's in 12 guage were chambered for 2 3/4" shells until 3" chambers were added in 1935 to their heavy duck guns. Second the fallicy that you should stick with light trap loads. Most trap load have similiar chamber pressures as do magnum load @10,000 to 11,000 psi. Just because it doesnt kick as hard doesnt mean the pressures are less. Next all manufactuers, after producing a gun fire a "blue pill" pressure round to proof the gun. These proof rounds are customarily loaded to 10% to 15% greater pressures than factory loaded ammo. The SAMMI maximun pressure for a 12 guage is @13,000 psi. Forgive me if I am a little off on this figure as my memory isnt as good as it used to be, however I am close. So most manufacturer had custom proof loads loaded 10% above this maximun psi figure. Some suggest light loads? Winchester proofed each gun with loads 330% above maximun psi. That is NOT a misprint, 330% above maximun psi. Reference Winchester model 12 historians Midas's book "THE WINCHESTER MODEL TWELVE" page 24. AS for "shooting loose", in my decades of shooting model 12's I have never witnessed a loose model 12 from shooting. An old friend and trapshooter has a trap gun made in 1950 that shoots many thousands of rounds a year for 62 years and it is still tight. Unlike modern mass produced guns of questionable quality, model 12's were milled from solid billets of steel. No plastic, potmetal or stamped tin parts. These are the tanks of the pump gun world. Now for some unsolicited advise. Dont take the gun down in half too often. I have witnessed one model 12 that had been taken down so many times the threads were all but gone. The owner would wrap what was left of the thread with black tape and shoot it a few thousand times before the tape gave way. Next STOP slam firing these guns. They were never meant to be slam fired. Just because they can be does not mean they shoud be.