I have a 4 arrow two piece pse quiver on my Firestom lite. I love it and wouldn't trade it for the world but I'm not familiar with the topgun quiver. when I checked th PSE site it looks to be identical to my quiver.
http://www.pse-archery.com/2005_prod...s/TWO_PC_4.htm
Not knowing what bow you have it's hard to say but on my Firestorm (ata 30") my arrows (fletchings) hang down below my cam. It's all but impossable to aviod on the shorter ata bows. As far the quiver itself it's awesome. It fits extremely snugg and I get virtually no vibration from either the quiver or the arrows in it. On a longer ata bow the arrows should be more secure as the quiver will be holding them by the tip and closer to the fletching on the other end of the shaft. Becuase of a short riser the arrows are attached with about 12" between each the contact points on the quiver and I have about a foot of shaft beyond the end.
If that makes no sence just ignore it. It's a great quiver and I'm sure you'll be happy with it.