hello everyone. i was wondering how many
of you have changed your bushmaster m4
into a free floating barrel? also how
difficult is it to change from the stock
handguards? bushmaster's catalog advertises
for $149, any better deals out there? thanks.

The one down fall to changing out the hand grips to a float tube is that the tube gets hot real quick.  
If you were using the rifle slow firing or target shooting, then the tube would be a benefit.  But, if you are using the rifle for pit/rapid shooting, you are going to find that the tube get too hot to hold onto, even with light gloves.

Just my take on carbines and float tubes.
Hope it helps.

I changed my M4 to a free float system, but it was with the ARMS SIR. Not a cheap option, but it free floated the barrel and, to my suprise, increased accuracy significantly. Plus, it was an easy installation, and it is about THE best option for increased cooling. I love it.

Quoted: I changed my M4 to a free float system, but it was with the ARMS SIR. Not a cheap option, but it free floated the barrel and, to my suprise, increased accuracy significantly. Plus, it was an easy installation, and it is about THE best option for increased cooling. I love it.

Ditto.  On a Colt 14.5 M4 it surprised the hell out of me at 100yards.