I use the "Possum" hollow bore guide #86 for my M77 300 WSM......This guide not only keeps the rod from contacting the bore, but it also keeps out any cleaning materials from getting into the magazine area......Simply remove your bolt and then slide in the bore guide until it stops. Makes cleaning from the breech very easy, with no potential bore damage from the cleaning rod or a mess in the magazine to worry about! Works great!.............Available from Midway USA
I've been using Sinclair Bore guides for all my rifles. Keeps garbage from entering the magazine area. Sinclair will make a bore guide for any rifle on the market to the best of my knowledge.