No, they are not delicate on the gun. The making part is a problem because you have to cut not only the handguard but also the thin heat shield inside and in a way that you do not mess up the little pin that holds the heat shield in place. I buy the triangular handguard cap that fits into the delta ring and then make my own handguards. I do this because I make them a little longer than Total Silence or others like Hay River Trading used to do them. That way they are really tight and do not move or rattle at all. Only problem is that you have to take the front sight off to put them on and take them off.
Everyone that I know who uses them likes them even better than the regular carbine handguards. They seem to dissipate heat better, but I am not sure why that is. Of course they do not dissipate heat better than the M4 handguards.
Charles Tatum
Alamo Professional Arms