This question is specifically being asked about my AR10A4 but I assume the general info would apply to any AR system.  I currently have the ALOSTYR railed HG on my rifle.  They are direct replacements for the standard A2.  They install using the front cap and delta ring.  They then use three hex screw on each side to clamp the upper and lower halves together.  The final step is to tighten four more hex screws that contact the barrel just behind the gasblock...the area where the barrel profile begins to get larger.  They are extremely tight and do not move once everything is tightened.

I am wondering if the four hex screws that contact the barrel would have any ill effect on accuracy as opposed to not having them touch the barrel.  What are the chances my rifle would be more accurate if I used the lighter weight standard A2 HG instead of the ALOSTYR?

Or because it is not a FF system anyways it won't matter how much or how little is touching the barrel.  

BTW - The rails are mainly used for a bipod attachment.  If I'm going out to check the fence line or horses at night I will attach a surefire to them.

Thanks for the time.

Wondering the same thing myself.
Surfires and YHM types that look like they may clamp to bbl. nut.  
I have noplace where I can touch any of these, so any info welcome.

FWIW, sling tension (if you use one) or the bipod ya mentioned will probably have more effect on POI than a non-free-floated handguard.

The regular handguards are probably no better or worse than your current set-up.

Mike

I do not use a sling when shooting.  Most of the time I am either holding the mag well or have the delta ring sitting in teh notch formed by my thumb and index finger.

When I use my bipod I try not to put forward pressure or downward pressure on it.


My concern is that the four set screw actually contacting the barrel would produce more of a problem than the A2.  Although by touching the front HG cap I guess technically both types contact the barrel.

Anyone else have a thought?

Thanks