I shoot Carbon arrows through the Aluminum bisket insert(two color).
I switched over from the carbon insert because it was to tight on my Carbon express Maxima 350.
Thank God I did!!!.....What a difference..... MUCh better...faster, less speed loss and more accurate ...... try Blazer vanes ( when fletching put a dab of glue on the front and back of the vane ) ......they work awesome and no vane damage .......also minimal speed loss