Button-rifled...something you used to only see on much more expensive rifles...
Not trying to jack the thread--but I believe that you are in error.
Button rifling is the fastest and cheapest method of rifling a barrel. A carbide steel button with the reverse impression of the rifling is pushed through the barrel blank. The rifling is actually swaged into the barrel steel.
It is economical and there are lots of accurate barrels that are button rifled. Unfortunately, if the barrel is not stress relieved after rifling, it can have a big impact on accuracy.
The most expensive--and best--way to produce a good accurate barrel is by the single-point cut rifling method. A cutter is pulled through the barrel, and it cuts one groove at a time. This eliminates barrel stress. The barrels produced by this method are the ones you see on rifles where the shooters demand extreme accuracy. Three examples of cut rifled barrels that have won numerous awards for accuracy are Kreiger, Bartlein and Obermayer.
If your rifle throws shots out of a group when it's dirty, then clean that bore. The most important shot from any rifle is the first shot. You should zero your rifle and then take note of the first shot from a cold, clean bore.