Why go custom shop? The new std barrel is 23" full bull. And from tests I have read, and some of my own, thats too long. 18-19" is supposed to be the optimum length any way. I have 2 std barrels, one is a 14" pistol. The other is a 23" that has been shortened to 18" for a carbine setup. Both will shoot under 3/4" at 100 meters on a calm day easily. My daughter used the carbine on a prairie dog trip a few weeks ago and it was fantastic out to about 225yds. KN