I have not checked them all, but the gas ports on slug barrels I have checked are bigger than the normal field or trap barrel, and almost as big as a Skeet barrel. Jerry Kuhnhausen found the same thing. The primary difference with the Magnum barrels is they utilize one gas port instead of two. I was wrong calling the reduced recoil loads mouse fart loads; another multi-tasking failure, sorry.
As to whether or not the receiver will get battered by opening the ports, that depends on how much one opens the ports, and what they shoot through the gun afterwards, and what shape the buffer is in. And the quality of the buffers has varied over the half century since they were introduced. I do know the only cracked receivers I have seen were on guns that also had enlarged ports. Also, you will often see differences in performance with light loads between different supposedly identical barrels. This is very common with Magnum barrels. Some will only run with Magnum shells, and some work fine with 1-1/4 ounce field loads, and the trait goes from one gun to another with the barrel. I believe this is due to the fact that the shape of the inside of the gas port varies slightly, and that makes a big difference as soon as the gas velocity drops below supersonic, but there is no way to measure that. I do know that you can often get more gain by utilizing a slightly smaller than port size drill bit and wallowing it while turning so that you remove some material from both ends of the port than by straight drilling it out.
I always advise anyone to watch the buffer and impact area at the rear of the receiver and make sure you do not have metal to metal contact. As long as you don't have that, there will be no problems. The greatest risk in my opinion is when someone puts a regular 2-3/4" barrel on a Magnum receiver and starts shooting very heavy 2-3/4" loads. That heavier Magnum action sleeve can get going too fast.
I do not spread "rumors" about 1100s. Yes, one can "tune" the action. But, unless you are doing something outside the norm, you shouldn't have to. And let's face it, how many people really have a clue what they are dealing with; they just do what someone told them without really understanding why. The big problem is when one does that tuning to get the gun to run with a specific load or a shortened barrel they often render the gun unsuitable for what it was originally intended to do. All well and good, it's your gun, but unless you clearly mark the barrel, then later when you sell it someone else ends up with a problem. I do not mean you personally, I do not know what you do, but we both know a lot of people will screw up a barrel and then put it on ebay, buyer beware, and then someone else ends up bitching about that lousy 1100 they have.
I like 1100s, a lot. I still have the one I bought in 1963. About 40 other semi autos have come and gone, but the only semis I have left are 1100s/11-87s. I hit what I am shooting at with them. They won't go as long between cleanings as some of the newer designs, but they have never not gone long enough for me. They are not as flexible as some of the newer designs, but I have different guns for different uses. They aren't as light as some newer guns, but although I am far, far, far from the strong safety I once was, I don't find myself having to resort to dragging them. And when you are using them to do what they were intended to do, I don't think there is a better gun going.
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