I'm not one to push bullets as fast as I can get them, so the 3 land barrel works great for me. I think if your going with a really fast twist, having more lands is a good thing.

There is a new process out that's kind of like the Tritanium Nitride process, but is different. The guy who developed it took two years in doing so for the military. The concern was the fast burning up of the throats of the barrel. He claims 40,000 rounds from an AR-15 with no wear at the throat and about 150 FPS more velocity.
Scott Null, owner of Savagegunsmithing just got back about 20 customer barrels from customers who want to test the process. It makes the barels punch about 100 on the Brinal scale and any mods to the barrel such as cutting for a muzzle brake have to be done prior to the treatment.
If it works as advertised, it will be a major break through for all shooters, especially the BR shooters who change barrels once a year due to wear in the throat. Right now, Scott is the only one the guy is doing barrels for other than the military. If you want more info on the process, call Scott at 208-313-1570, he knows far more about it than I do.

I'm waiting to see the results before I get my barrel treated and will most likely start out with a new barrel.
It costs $240.00 per barrel for the treatment, so it's not something I want to jump right into. The guy has the barrels and test results to back up his claims, but I want to see what kind of results the people who Scott had the process done for get.

I'll try to keep you all posted on the results. Scott will be checking the barrels with a bore scope as they are shot to see how the throat wear if any is going.

Back to the original post, I think in the slower twist barrels, shot at reasonable velocities, the 3 grove barrels are the best things going. If I was to go with a fast twist and pushing the bullets at high FPS, I'd want more grooves. Those old 2 groove barrels sure shot excellent, but they were not a real fast twist and not shooting the new fast cartridges.

John K