Just throwing this out there...could it be one of what Pac-Nor is calling "polygonal" rifled barrels??? The reason I ask is because I barreled a rifle for a guy that opted to use one of those and it didn't look like the "polygonal" rifling I have seen in other bores, such as the Glock or various other barrels I have seen titled as polygonal by their manufacturers. Then again neither did what I saw in a Black Hole Weaponry barrel either. I guess the term is subjective to those that use it.
The Pac-Nor Polygonal barrel I did see was a 7mm, had 6 lands and grooves and what it looked like under a bore scope could best be described as nothing more than "6R"...maybe they sent the guy the wrong barrel, but it clearly had flats on the tops of the lands and what appeared the same as the "Ramped" sides of the lands like a 5R. Having six of them inside a 7mm barrel could maybe have caused it to possibly look like the lands were as wide as the grooves??????
I will say this...if it is don't be too worried about it!! The one I installed, whether it really is what they are calling polygonal or it was a mistake, shot absolutely fantastic!!!
I have barreled many actions, some I was able to follow up on and some not, but this one goes down as the most accurate 7mm-08 I ever did.
Edit: I just took a look at their website and they show a 8.6 twist in a 6.5mm with four grooves. They do have the polygonal 6.5 in an 8.5 twist, but they don't say how many lands and grooves it has.
I would go ahead and try it...a good barrel is a good barrel regardless of the rifling style or configuration. I have never been able to tell by shooting, cleaning or measuring groups on targets what type of rifling a barrel had.
