Rshooter,
Respectfully, the OP (original poster) is not the only one who will be reading this thread, and all the answers to it that appear here. Others will see it too, and they might well misinterpret the outright statement that "the receiver is the deciding factor when it comes to shell length."
Example- a while back I bought a used Remington 870 Wingmaster, vintage 1976. The serial number ended in M, identifying it as having a magnum receiver capable of handling 3" shells.
But the gun was not wearing its original barrel with a 3" chamber- instead, it had a Wingmaster barrel with a 2 3/4" chamber as installed by the previous owner. If indeed "the receiver is the deciding factor when it comes to shell length," then it would be perfectly fine to shoot 3" shells in that barrel, correct? Obviously this is not the case- it would be dangerous to fire 3" shells in a 2 3/4" chamber, even though they might well function through the gun with no apparent problems.
We here at The High Road have a responsibility to our fellow members and the many guests here (looking at the main page for the Shotgun forum right now, there are 136 guests on the forum- who cannot post questions- versus the 16 members, who can ask for clarification if needed). A lot of people actually put the advice and statements they see here on THR to use in the real world. We have to be VERY careful to be as accurate and clear as possible, both in the opinions we offer and in the words we use.
I was trying to be not argumentative, but only precise and unmistakeably clear in my earlier reply. Just as I am now... I'm sorry if I fail to achieve that goal.
lpl