From the Sierra Manual, for 140-142 grain bullets 37.7-45.7 grains RL22 for 6.5x55. My manual is not new enough to have the 130 but from experience with other 130 grain class bullets (Hornady and Berger) one have a long and the other having a slightly shorter bearing surface that the Sierra, 43-47 grains.
As Always start at the bottom and work up like any data you get. Your action may be different, My Steyr SBS is pretty well insensitive to pressure so 47 grains may be warm with the 130, but I have seen where others have reported basically filing the case to the rim and packing it with a bullet. I doubt you can pack enough in there with a 130 to cause anything beyond a stiff bolt lift with a strong action. However there is little difference between observed maximum loads with it using 130 and 140 Bergers. Having not used the Sierra 130 this is why I STRESS WORK UP STARTING AT 43 GRAINS. If using a 98 Mauser action maximum loads will be lower, or they are with mine. I have 4 6.5x55 rifles with the 98 and 38 I use lighter loads. I have never pushed all the way to max on the M38.
Speer lists 46-50 with 120 grain bullets and 45-48 with 140, both flat based bullets. You will most likely see some great velocity gains with RL22 with your longer barrel. It has always been a good choice that most say is too slow for the cartridge. In my short barreled Steyr I use 47 grains of H4350 with a 129 Hornady and a Fed 215 at 3.1". I get groups in the .3-.5" range regularly at 100 yards.