Why Vent Rib?

[GGGLOCK]

Dave McC's post on bead sights made me wonder...

What is the purpose of the ventilated rib on some shotgun barrels? Is it to aid sighting, and if so, what does the proper sight picture look like. Also, how does a vent rib-bead-sight setup compare in terms of acquisition time to a ghost ring setup...faster, slower?

Finally, is there any utility in having a vent rib on an HD gun?

TIA for your insights.

 

[Dave McC]

During high volume firing, like the clay games and dove shooting, the vent rib dissipates heat faster, reducing mirage,GGG.

HD guns do not reach that volume of fire where mirage is a problem(I hope!).

As for speed, a bead sight MAY be faster than a GR setup, but the difference in trained hands is a smaller fraction of a second. Both work fine for HD, and a bead works better for shooting flying stuff.

Better to compare a bead on a plain bbl vs one on a "Ventilated" rib bbl. The plain bead will tend to shoot a bit higher than POA, and the Vent rib bbl will TEND to shoot flat.Acquisition times will be identical.

Stand by for lousy graphic....
_._

The bead should look like it's sitting on the rib at the receiver.IOW, no extended view of the rib.

And no particular utility to a vent rib on a short bbled HD tool, but no major drawback either. Actually, I think they look kinda cool(G)...

Hope this helps...