Yes, it is slightly tapered but it is a very thick barrel... I forgot who made these barrels... Doc told me when I called him but I have lost it... but I think I might be able to find it...

Found it... It is a Wilson...

Doc's words...The rarest WHITE rifle, so rare I didn't have one in my collection for a while. Only 2000 were made in 1994 and all were sold by 1995. Wilson made the barreled actions and did such a great job that no Lightning rifle has ever been returned because of accuracy problems. I have never had one traded in, ever!
The barrel and action were one piece in one inch diameter, the only caliber was .504 with a slightly tapered 22 inch barrel , the lightweight SG-series action (SG means Small G) was a mirror image of the Whitetail and Bison actions only with the cocking handle on the right and the trigger safety on the left. Internal parts were otherwise the same as all other G-Series rifles except the hammer, which the idiot machinists made slightly larger. Stocks were lightweight Birch, painted black with a rubber recoil pad. Weight was right at 6 lbs. I never saw an inaccurate one.