Gary how does the 401GNR compare in different barrel lengths

perfectly, and it looks a little better to me. That one inch won't effect performance worth worrying over. With a barrel band sight like mine it looks less crowded than a 5.5", just perfect to me. Now in a solid breach gun the length can be used to optimize slower powders and really spike velocity. Nate has his zippin. They all are flame throwers with H110!

I need to put my scope back on to carry in Gary's scoped cross draw rig. It is a supreme hunting handgun for a portable set up that still feels like a true handgun.

4 1/2" barrel would be minimal velocity loss. You normally lose about 30 to 35 FPS per inch so that small of a change would probably show a velocity loss around 50 fps.