The wife's gun is a Ruger 77 ultra lite in .243 Winchester and a Nikon fixed 4X scope. It's not a mark II, but the old style tang saftey model. I hunt it more than she does.....an average group is about an inch with 100 grain winchester silver tips.
I'm not sure I understand your question, but usually you can subtract 25 to 50 feet per second for each inch removed from the published stats. So, if your load is listed with a 22" barrel and you go to a 20" barrel which the ultra lite has you could expect a loss of 50 to 100 fps. This loss is insignificant.
Don't get caught up in the velocity hype......if a fellow needs more power, then the thing to do is go up in caliber and make a bigger hole. Velocity extends the range of the caliber. Hit where you need to and things work out well. No caliber, at any velocity can cure a poor hit, so get something that you can learn to shoot well and 99% of your problems are solved.
I think the ultra light is an excellent choice. Her's has a limbsaver recoil pad and the felt recoil is tamed to the level of a .223.
You may need to have the stock cut down a little depending on how the gun fits......with the rifle resting in the crook of your elbow, the trigger finger should curl around the trigger.......If it doesn't it's to long......this is a general statement, and over simplifies stock fit greatly. Felt recoil is greatly reduced if the gun fits the shooter properly.