M4 just arrived and note that it came with the enhanced charging handle and bolt release found on the gen 2. This is a 11721 LE. Pleasantly surprised, and glad I held off on ordering aftermarket options.
Speaking of aftermarket, bt-parts is running a firesale on the B&T quad rail ($125).
Can't wait to take this out to the range!
Today I got a chance to try swapping the handguards from my t-pro, and my Dad’s older M4.
The rear capture ring of the old barrel has a spring, the new one doesn’t, but it does have two springs on the handguard itself.
I can’t speak to how it would hold up long term, but it does fit.