What many folks don't really understand is how much more potent, a pistol cartridge is out of a rifle than it is out of a handgun. We all know that a 357 mag and a 44 mag is substantial out of a handgun, but put them in a rifle and the velocity is substantially more. A 357 mag out of a rifle barrel is actually just behind a 30-30. The big difference is bullet drop. Both the 357 mag and 44 mag are both 100-125-150 yards depending on taking the time to do some real bullet testing to check the drop. Past 150 yards you can have substantial bullet drop.
Vito, I'm not sure if your friend has totally consider the use. Is he talking in the house, outside the house, in the woods (at the cabin)? Obviously the 44 mag will have substantially more penetration. If I was trying to keep people away from my house I'd be using a good 38 special round, plus you can put one more round in beyond what you can put in a 357 mag tube.
When Jeff Cooper recommended the 30-30 rifle as a personal defense rifle, people lived farther apart than they do these days. It's hard enough to keep a pistol round out of a pistol from over penetrating but stick it in an 18-1/2" barrel velocity performance improves.
If I was going to use one of those I'd certainly use a side loading rifle and consider a Marlin 1894 or a Rossi 1892.
Examples of above:
The S&B 158-grain JSPs gave carbine numbers of 1451 fps and 739 lb-ft, but the chrono battery died before we could measure them from the revolver.
With Remington 125-grain JHPs, the revolver got 1442 fps and 537 lb-ft. The carbine got 2038 fps (!) and 1153 lb-ft, for a 41 percent velocity gain and 98 percent boost in energy.
160-grain Hornady Leverevolution: 2132 fps, 1615 lb-ft.
Don't doubt for a moment that the 30-30 is a substantial cartridge, but don't discount the pistol cartridges ability to penetrate.