Always passthroughs with aluminum and no passthroughs with carbon. Simple enough. Just my opinion, you understand, but I think it's probably because those arrows are so much lighter than the aluminums you were using. I am very much of the opinion that, while guys using high performance bowsthat put out plenty of KE can get good results with light arrows, when you go downthe scale in draw weight and KE, then arrow weight gets very critical.

If you like the durability and small diameter of carbon arrows, I suggest trying Carbon Express Terminator Selects. They're fiberglass/carbon composite arrows andhave enough heft to carry more energy and momentum downrange for penetration. It takes them a fraction of a second more time to get there and trajectory isn't as flat,but they hit a lot harder than straight carbons. Comparable to aluminum, in that regard.