Jack O'Connor used to use 39.5 grs. of IMR 4064 in his Roberts with a 100 gr. bullet. Said the cases would fall out of the gun and they would last "at least 40 times."
What has impressed me with the Bob is that one can get good velociites at low pressures. That and it can be loaded with alot of diffrent powders. Makes for lower muzzle blast vs. my usual loads in the .243.
There is alot to like with the Bob.
Heck, I've even tried .257 Roberts ammo in my .25-284, mostly to see if it will feed from the magazine. It wouldn't completely chamber BTW.
Why ? Because I'm toying with the idea of making it into a Roberts, maybe with a heavier, or a shorter barrel. The Disease never sleeps does it ? E