I wear my bag and horn on the left side.
I am right handed.
As has been said before, it does keep the rifle and bag/horn from getting together. Also, i see it as a possible safety advantage, keeping the powder container as far as possible away from the flash of ignition. Especially important for folks that tie the stopper onto the horn and forget to put it back into the horn spout when loading. Just let 'er dangle!!!
I notice that October Country builds all their pouches standard left side carry. That's interesting. I also noticed that the fleece bag that Cabela's offers is set up for left hand carry. Hmmmmm. Thinking back on other pouches, I think the Thompson Center bag was universal as was the Uncle Mikes. I think they both used a three piece strap.
Well, who knows? I think any way one does it is right.
Beaverman, why not build the bags so they hang from rings and rivet the straps on when they are sold, as the customer wants them. It's a thought. And it makes for a bag that hangs well, too. That way you could get the pouches sewn up ahead of time and determine carry side when sold. RE: the short starter loop on the side, it's no big deal to put one on each side of the pouch. Make it a lot more universal. Course, what do I know?
Big Smoke