I’ve kicked this caliber around for a while as well. Could never do it though. after looking at the, the FN products aren’t worth 1/5th the asking price. I came close to picking up a used AR57 upper but decided it would end up costing too much to shorten the barrel for an SBR. Hopefully Ruger will breath some life into the cartridge but they need better loaded ammo.
The main reason why I had never owned anything chambered in 5.7x28, much less adopted it as my main defensive carry, is due to:
A: Long term supply logistics,
AND
B: The quality of "commercially produced" ammunition.
First off, the popularity of the 5.7 cartridge had never really blown up like the others. I think it would be safe to assume that had it not been for the
Stargate television series and it's fan base, the cartridge might not even have become available here in the States. If I were to work in a gun store right now, I bet that one whole week can pass without anyone asking for a box of 5.7x28... And herein is the problem for long term reliability. In an SHTF scenario, resupply would be an astronomical task, as this ammo is not something you can just expect to find on dead enemy combatants.
On the second note, FNH seems to have adopted an even more politically correct approach to it's civilian sales than the US laws regulating ammunition. The 5.7 is technically a rifle cartridge, and aside from not allowing commercial sales of penetrator tipped ammunition, velocity is not a regulating factor in commercial rifle rounds. Yet, the SS197SR, which currently is the only commercial loading available, is underpowered and anemic. You can handload the round but before you carve out a chunk of your wallet for all of the components necessary to support this load, consider the A section of this post. Is this something you plan to rely upon for long term survival, defense, and food procurement? My personal answer is "no".