Frame size is only one criteria when deciding, as you wish to do, whether one gun is more suited to the use of factory standard pressure loads than another. The assumption would be that 5-1 (Is that what they are?) marked barrels are thicker in all areas than your #2 frame GH, but you wouldn't know without measuring. We always have a good time measuring wall thickness at the Southern Side by Side. Bring your gun up north in April and we will measure it and test fire.