Can someone link me to a decent quality bore guide for the 30-378 Weatherby? I can't seem to find one anywhere. Supposedly Possum Hollow #112 fits, but I can't find one.
This is what you want but please call and speek with a sale's rep to order. As the guide I have linked you to is for the 378 and not a 30-378. They do have a 30 cal bore guide as well but I do not know enough about the MK V action to say it will work.
Try editing you post title to read I need Weatherby MK V help or something like that. There are 2 men here I know of using this action Tyler kemp is one he may have some advice for you.
If all else fails you might try to send a P.M. to Long Time Long Ranger. He's a wby buff. He may be able to point you in a direction as to where to get one even for a Rem.