It is primarily a Glock issue in that you see it more often in brass fired in a Glock.GasGuzzler wrote:I thought the swelled case issue was a Glock issue over many calibers not a .40SW issue. There's an XD40c in my family that doesn't swell brass...the ejector dings it a little though.
It's not an issue I would expect to have a large problem with since I'd ditch any picked up brass showing signs of it. However with both Lee and Redding selling systems to 'iron out the bulge' and people using them to return pregnant brass to something that will fit into the chamber (Rather than using them according to directions) it makes pick up brass a bit more suspect. Although the Lee system can be used for calibers other than .40 that's the one you see most folks messing with.
As Ohio3Wheels mentions it is a situation you see much more often with warmer loads as well.
.40 being quite a bit warmer than .45 ACP and 9mm generally not having as many problems due to size/area/form factor you tend to see the problem more often in .40 as well.