And bump up the gas before you replace the buffer. Though, they have found over and over on here that a properly sized port and a buffer in the 5.4oz range is reliable. With your adjustable block, you may be able to tune the port to work after you open it up a bit. I’ll put on my fire suit...my recommendation on the buffer may bring me some heat. Logical thinking doesn’t always work with these rifles, but the math seems to. Which is why they recommend what they do.