Josh check the ruger site for 1790 its a 2.5 inch gun https://ruger.com/products/gp100/specSheets/1790.html

Its a 2.5 inch barrel. from Ruger web site.see ******** MODEL NUMBER: 1790 CALIBER: 357 MAG
GripsCushioned Rubber with Hardwood Insert
Front SightFiber Optic
*******Barrel Length2.50"
MaterialAlloy Steel

Capacity6
Rear SightAdjustable
Twist1:18.75" RH
FinishBlued

Overall Length8"
Weight36 oz.
Grooves5
Available in CANo
Available in MANo
UPC7-36676-01790-4
Triple-locking cylinder is locked into the frame at the front, rear and bottom for more positive alignment and dependable operation shot after shot.
Grip frame design easily accommodates a wide variety of custom grips.
Disassembly of integrated subassemblies requires no special tools and allows for easy maintenance and assembly.
Transfer bar mechanism provides an unparalleled measure of security against accidental discharge.

The barrels 3 inches with an overall length of 8.5 inches. Think it's just the picture making it look smaller. Hope this helps.