I've searched these forums a bit, and after all the helpful input I received, I was wondering what the general consensus (if there was one) was on the best mag tube extension for my newly modified M4, and also what a good shell holder would be. I would prefer a holder that I don't have to drill or modifiy my M4 with, maybe even a cloth one that would stretch over my collapsible stock, if that's feasible. I'm not looking at getting a rail system on my M4, as those seem a bit ridiculous to me (just my humble opinion) so the shell holders I've seen that include those I'm not to fond of.
EDIT: And while I'm not too worried about 922r compliance (must be one of the most inane laws I've ever heard of) I would like to eventually comply, so any advice with my on-the-way C-stock, and the mag extension I'm wanting to buy would be appreciated.