S&W 1000 and 3000 shotgun barrel exchange question

[Sirrie]

I have both S&W 1000 and 3000 shotguns and found that the barrels are dimensionally identical and readily exchangeable. If I use a 3000 barrel in a 1000, I imagine all would work except that it will not cycle the action because there is no gas port on the 3000 barrels. My question is what would happen if I use a 1000 barrel on my 3000? Is the escaping gas a problem (because of heat and pressure) or the front end stock will be enough to contain it?