Accuracy gains, if any, with true free-floated AR barrel?

[808///M3]

Strictly a theoretical question, to satisfy a curiosity.

What kind of accuracy gains could be expected from using a barrel without a gas port drilled into it? Consequently, there's no gas block or gas tube to affect harmonics.

Assuming a high-quality barrel is used, how would this compare to an otherwise identical AR using a low-pro gas block and free-float rail?

I recently read a thread in which a user stated he was seeing unusually large groups because an add-on rail section had been touching the bottom of his gas block. Eliminating the small amount of contact reportedly improved the groups.

[Samson1]

i'm thinking this belongs in the bolt gun area. interesting question though.

[MistWolf]

David Tubb believes firmly enough in completely free floating the barrel for ultimate accuracy that he developed a bolt action rifle based off the AR design that has pretty much come to dominate in it's field of competition

http://www.davidtubb.com/

http://www.davidtubb.com/davidtubb/content/templates/common/pdfs/2000_concept.pdf

[Jippo]

There are rather accurate piston guns out there, so even though you probably would gain some accuracy in leaving the gas parts out the difference is easily lost in other factors like ammunition selection/development. I'm just saying that there are other factors out there that have far bigger impact on accuracy. I'd work with those first.

Having something arbitrary like rail section touching the barrel will ruin the accuracy, but a gas system will not.

[MistWolf]

When it comes to fine accuracy having a gas block and piston or gas tube can have a negative affect. In a fighting rifle, the advantages of the self loading rifle outweigh the small loss of accuracy. In a competition rifle at that level, it could be the difference between winning and losing