Your velocity loss "per inch" of shorter barrel length will average around 15 to 25, maybe 30 fps. Not much difference in overall velocity between the 18" vs the 20" or even the 22" for that matter.
Only way to know is to chronograph loads through that rifle and one with a 22" barrel -- could be as much as 50 fps per inch. The only thing that really matters is if the 18.5 inch barrel will produce "enough" velocity, and I'm fairly sure it will.
I`d look for another "NEW" Ultralite on Gunbroker. For me personally, I don`t prefer that "international" looking stock. That rifle looks like you belong in the French Foreign Legion or in some other European army and not looking a hunting rifle,,even though it is a hunting rifle.
I don't think the French Foreign Legion or any other European army purchased full-stock Mannlicher-Schoenauer sporting rifles to equip their troops, so I fail to see how carrying one could put one in mind of such a military unit. Lots of European and a few American explorers in various wild and unmapped parts of the world carried M-S full-stocked rifles in the early part of the 20th Century, but that's not a "look" most outdoorsment would likely object to. Even if they were prone to going around wondering what their rifle made them look like.
"Honey, does this rifle make my ass look big?" is not a question I ever hear from my hunting companions...
Also, why did the last owner trade that Ruger international in or put it on consignment?? A possible problem??
Any rifle being purchased, new or used, ought to have a rather careful looking-over by someone sporting a clue. I've been rather pleased to buy a number of firearms the previous owner thought had a problem. Ignorance is frequently easily repaired.
Dennis
