I can't speak to what your results would be with a Sig. Here's mine with an XD. I bought a bulk package of Rainier factory seconds and have had mixed results. The accuracy is great, that attached image is more accurate than several groups I shot that day with .355 ammo. Note the charge though. I don't know if it's Rainier, the bullet diameter or both, but while staying with that OAL, and going up in .2gr increments that was the lowest charge that would reliably cycle. I've loaded a few hundred of them so far and seen no indications that they are unsafe.
Rfwobby - Thanks for the idea. I'd been wanting to slug my 9mms, but hadn't thought of that.