3" mag barrel on a 2-3/4" receiver/shotgun?

[71Rcode]

Any thoughts/experience firing 2-3/4 12ga shells through a 3" 12ga barrel on a model 1000 originally chambered for 2-3/4 only? I measured the receiver ejection port/opening both my 2-3/4" and 3" 1000s and its identical. Could it be S&W made both receivers and guts identical, with the barrel chamber length (and perhaps strength) being the only differences?

[H Richard]

Usually you can fire any shell through the receiver it is made for regardless of the barrel's chamber length, but you can't shoot the longer shell.