Justin,
I agree with the guys that are telling you to leave out the weight tubes. I would suggest you don't want to get carried away with the weight either. For a 50 lb bow I think 550-650grn would be about right and you should be real close to that weight with the way you were gonna set up those arrows...minus the weight tubes. I shot right thru my last Alberta moose with a 520 grn carbon arrow out of a 60lb bow with a 2 blade magnus and I didn't have an EFOC like you will with your setup. That will also help penetration.
Randy