On the Stevens 200 the twist rate may not have alot to do with it. I've seen many of these rifles at our local gun shop. Most have the barrel off center in the stock and have barrel/stock forearm contact on one side of the barrel or other. Having the rifle bedded in the stock will center the barrel relieving the uneven stock pressure on the barrel. This has corrected many of these rifles accuracy problems. I mean it is a Savage without the accutrigger. The rifles are inherently accurate.