Originally Posted by Gh0zt36
I mean you cant shoot lead through it because of barrel leading ... So Im just wondering are there any advantages for it being rifling of choice?
Here's an excerpt from the previously mentioned article that answers your question:
"The advantages of barrels with polygonal rifling include a smaller gap between bullet and bore, leading to slightly higher bullet velocities, and smoother bores that accumulate less fouling, making them easier to clean. The barrels are also generally more accurate because there is less bullet deformation by the "grooves" (less "bite" into the bullet) and because the bore's surface is formed with more consistency. Because the rifling has no sharp corners to erode, barrels with polygonal bores have a longer, usable life, since they retain their accuracy longer. Finally, the hammer forging process used to create barrels with polygonal rifling is less likely to leave traverse tool marks, another cause of fouling, and a problem more common in conventionally rifled barrels. Accuracy, longevity, and strength may be the greatest practical benefits of barrels with polygonal rifling. A limitation is their inability to be safely used with lead bullets."
As you can see there are many advantages to polygonal rifling (other manufacturers use it too). Specially if your primary market is military and law enforcement who use jacketed bullets.