If I may give you a little advice from experience, what you have proposed is a recipe for disaster for a couple reason's.
My nephew had a basicly inentical gun a few years ago a 22-284 Pac-Nor 3 groove 1-8" twist. it was a nightmare because this chambering is wayyyy too over bore and combine that with a 3groove barrel and there are very few bullet's that will make it out the muzzle intact, the 75-80gr A-Max wont, the 75-80gr VLD Berger's wont. the only bullet's that will shoot in this combo are the Sierra Match King's 69-80grains.
If you have your heart set on the 22-06 so that you can shoot these other bullets a 5 or 6 groove barrel is a must.
Then the other thing to consider is barrel life.....500-600 rounds top's and it will be toast.
B
Tell me more about the theory behind not using 3 grove, because I saw others advocating it.
