Features of new M4, WITHOUT a pistol grip stock.

[Hastings]

A question regarding a new production M4, without the pistol grip stock (just the solid non-pistol grip stock that we would see on any typical rifle):

1. Does the stock unscrew the same easy way that any of the pistol grip stocks come off?

2. Does it come with a recoil tube that has the 3-position detents, even though they are not visible or usable with that stock?

3. Do all the barrels have the threads on the muzzle that are necessary for attaching chokes on the end of the barrel, or do you have to look for that specific option on only some rifles?

Thanks again so much.