Underclocked - When I shot your genesis I used the triple 7 primers (with triple 7 powder). I did notice that with each shot the action got tighter, but it never got to the point that I couldnt open or close it.

I would recommend trying some different primers, or like you mentioned, wiping off the blowback from the action every few shots.

Also, I had the best accuracy results with 250 gr. shockwaves. I also shot some TC maxiballs, but they shot erratically. I was using 2 T7 pellets.

Good Luck.