Idk if it's just me, but the 30 round spring doesn't look identical to the 50 round spring and I'm comparing both of them right now on my desk. I think the weight of the 30 round is a tad lighter than the 50 rounder to compensate for the 3in or so block inside the mag. I should give it a try though. I know the 10 rounders are waaaay diff springs, and when modifying a 50 or a 30 to a 10 round you get really inconsistent feeding, as I have noticed with a few mags I capped at 10 to make legal.
I know one thing though, the p90, ps90, and ar-57 are finicky as hell when it comes to mags, and rounds. Reason the clone mags are so prone to jamming, and reason reloads are as well. One thing our guns don't like is non factory fnh parts and ammo due to the lack of a gas system, and the reliance on pure blow back and mag spring push.
And btw, I'd like to see an uzi penetrate body armor as well as a 5.7x28 round. Just won't happen
There is a reason the 5.7 round is called the "cop killer" round, and it's not because its a new round. It's because it's absolutely notorious for penetrating level 2 and 3 armor, and in some cases level 5 armor. Heck level 3 armor is rated to 7.62 in most cases and the 5.7 still manages to shear through it like butter. The bullet design is the culprit. It's nothing to do with fps or grains, everything to do with physical makeup of the bullet, mated with a specific fps of the round.
Dravur, as far as I'm aware, the p90 mags have not changed at all, besides the ar-57 mags, which theoretically identical to FNH mags in terms of design, qc, and consistency. It's the slew of "clone mags" that bring a wack amount of difference to the line up. Reason why clone mags have such a bad rep... they aren't FNH mags and never will be, regardless of exterior look. (plus, they are made in china, and are probably full of lead. Eeek.
and 68wj, I'd never ever run anything but factory ammo and mags in my guns. The 5.7 rifles and pistols are FINICKY with ammo and mags. Thus said, I don't think any owner of one would actually even consider the stuff. It's one thing to put junk through an ak or sks, but not an FNH or AR-57. It's like putting generic 87 in your lambo. Doesn't make sense. The best takes the best to make er purr.