Yep, those are the ones I bought. Definitely makes a difference in USED Nerf accuracy. No difference in brand new I can tell.
One wrinkle. If your fins have been bent one way or another that causes the Nerf to spin the opposite direction than the spin the rifling causes, that round goes screwy at about 20 yards as the spin reverses. I trim my fins and use a detent in my barrels to keep the Nerf from sliding out.
I bought the schedule 40 white. The schedule would be too heavy for a hand held but in a motorized cannon, Not so much an issue. The inside bore is the same so why carry the extra weight unless you are shooting spuds and using much higher pressures than we use for Nerfs. I run 195 psi in my hand held.
Carefully planned irresponsibility is the KEY to mental health.
If you haven't grown up by age 50........
You don't have to......