aluminum 2419=0.268 = 438 gr.
Carbon 300=0.300 =321 gr.

aluminum 2219=0.337=417gr
carbon 340=0.340 =285

aluminun alsotats the carbon dosn't not because of spine but because of the material.
I have never shot carbon express and I don't know not what there marketing hype is all about and really don't care