I'm looking for some long term SHTF ammo and was wondering which of these two is a better round.  Any thoughts?  All opinions are welcome.

You don't need to solicit opinions...lucky for all of us one of our members provides us with fantastic factual reviews.
My opinion....for what it's worth.......IMI hands down. Think about it...... of all the maufacturers out there the Israelis are in shtf mode EVERY DAY. Failure of their armaments is not an option.

The FACTS indicate IMI is the better round not only with M193 but also with M855.
Here's the M855 FACTS for you as well.

Israeli ve. Serbian... do you have to ask?  

Both the Isrealis and the Serbs have had it rough in recent generations, and I agree that such conditions have one in "SHTF Mode" all day long. I would tend to agree with the IMI for first choice, but the PRVI isn't too far behind in second place. All munitions I have which have been made in Serbia have been solid, top notch products (an M48 Mauser, a 59/66 SKS, and  a bunch of ammo under all the names PRVI has used right up to when they got sold to Wolf). The legend is that the Serbs made (and warehoused) a Mauser (the M48) for every able-bodied male in their country. The Yugo 8mm ammo was some of the best surplus that dealers had ever seen. They even copied the German MG42 at their state arsenal after they booted the Heinies out, and Tito built up his army and thumbed his nose at both Hitler and Uncle Joe Stalin, and got away with it. It took Tito to keep it all together, and Yugoslavia finally descended into civil war after he died. Tough dude.

IMI all the way...with Win M855 as a backup.