This statement made me wonder why folks choose to free float their rifles and why they choose the length of tube they choose.

Myself, I have a couple of reasons:

I've always been an advocate of not giving the guy a shot at you while you extend a weapon into position beyond cover. My preference is to post up behind cover and roll out with the weapon slightly below eye level to ID targets and shoot. With a handgun or shotgun using conventional sights you are less likely to nail your cover than with the offset or the AR rifles. Plus, the results of shooting into a brick corner with a rifle are likely to be much more exciting than doing so with a handgun or even a shotgun.

Additionally, if you plop your barrel onto the barricade near the muzzle and bear down any, you will likely have some POI shift. How much this will matter is dependent on the range at which you need to make hits.

Therefore I prefer my tubes as close to the muzzle as possible for use of cover purposes. (this is my primary)

Secondary, I think in terms of my shoulders as the base leg of the triangle, the rifle as the 90 degree leg, an my support arm as the final leg. In terms of strength, and controlling movement, straight legs are better, so I like to stretch out my support arm as much as possible.

Finally, aesthetics. I like the look of the tube close to the muzzle. I get that the Armed Forces feel a need to be able to run a bayonet, but IMHO the standard M4 is one butt ugly rifle.

What do you all think?