I used a solid 1/4" carbon rod in my Goldberg ultimate, after the guy I bought it off used, well pretty much BROOMSTICK!

yerk, the pushrod alone weighed 4 ounces! I replaced it with my out carbon version with 4-40 rods in a Y configuration at the tail and WOW it's soo stiff and it's unsupported, but I too feel that there should be some damper if not only to stop the noise of the pushrod humming.