Thats what I thought. A few companies offer buffers that are thinner, but I didnt think there would be any room. I am thinking of building a CM type gun without the double springs, just porting to lessen the recoil. I was going to change it up a bit and put a slide with an external extractor on it , if that type of slide allows detonics type barrels? Before anyone says it, I know I'm bascically building a para, but hey at least its SA.