Anyone who tells you that you "have" to get a longer action to make the saum effective probably cries in the shower so their family doesn't hear. Of course a long action is better for a long bullet, but that doesn't mean it's a letdown in a short action. It's just that in long actions people can frequently exceed 7prc values, but in short you're more likely to get hot 280AI. Mild loads for me look like 7-08AI +P, but that's not typical. Look around on here in some of the threads at what people get for MV with the "handicapped" long bullets.
If you're into the 180 ELDM/berger thing, the Saami-ish saum can get them adequately fast to crush way out there. (Try to get to 2.9"). That said you will probably get the best external ballistics from the 168 leads and 140-155 coppers in a short action. But the 180 family is far from bad. If you want to pass 190 or use the 175 eldx, yeah you might want to consider single feed. But my hunting loads are 168 ABLR at 2900 and a 140 hammer at 3250, and that's out of a weak action. The bullets that make the PRC really shine aren't bullets I want to shoot elk with personally. It obviously can be effective, I just don't feel the need. There's nothing wrong with the 6.8 or 6.5 but the versatility of projectiles in 7mm just makes me feel good. You can load it like a light 6.5 prc or a midweight 30-06 and still get some change back.
If you have to do factory, that's a problem of course. But I have yet to talk to anyone who regrets investing in handloading. It's incredibly rewarding. And I don't know anything about PRC accuracy, but most folks experience a creepy level of precision with the saum. It survived Remingtons greasy failures for a reason. It's just hard to mess up.
That's my opinionated opinion. Good luck on your choice of project!