I'm sure this information may be posted elsewhere but I cannot seem to find it without an extensive search.  I'm looking for information on comparisons between a full fluted barrel and a lightwieght (as in Bushmaster Superlight profile) profile.  I have a RRA Mid-length upper that I am going to either have turned to a super-light profile, or full fluted (under the guards and in front of the FSB).  I guess there are three specific issues here:

1) Weight:  I suspect the fluted may be somewhat heavier.  Any information on how much heavier?

2) Heating:  The superlight will likely heat up quicker, as the Fluted has more surface area to assist heat dispersal.  Any comments?

3) Rigidity:  The fluted should prove somewhat less prone to POI shift with either extended shooting?  Comments?

It looks like a trade off:  Opt for a heavier fluted and get better heat dispersal and rigidity, or go lite and deal with less rigidity and more heating.  

Frozenny

Quoted: I'm sure this information may be posted elsewhere but I cannot seem to find it without an extensive search.

Hint: It's currently an active topic in the Rifles & Uppers forum - its also available at www.MD-AR15.com and www.Bushmaster.com...

1) Weight:  I suspect the fluted may be somewhat heavier.  Any information on how much heavier?

(Weight of 16" barrel with front sight base, but lacking barrel nut which is 2.5oz)

HBAR: 38oz
Fluted HBAR: 34.8oz
Lightweight: 28.4oz

2) Heating:  The superlight will likely heat up quicker, as the Fluted has more surface area to assist heat dispersal.  Any comments?

Unless you're doing real precions shooting (measured in the 1/2 moa or less) or are firing full auto the 'heating issue' is a non-issue.

3) Rigidity:  The fluted should prove somewhat less prone to POI shift with either extended shooting?  Comments?

See previous comment.