Is bore guide necessary when cleaning from breech?

[kernman]

Marlin's 336 can be cleaned from the breech, as everyone knows. Do I need a bore guide then, to protect the crown?

As I understand it, crowns are sometimes damaged by cleaning rods and brushes inserted from the muzzle end. Can the crown be damaged when cleaning from the breech end?

To clean the barrel, I plan on using Wipe Out as directed. Then, I will insert a brass, one-piece cleaning rod, and a bronze cleaning brush, from the muzzle end. Is there anything else I might need to protect the rifling, and the crown?

Thanks in advance for any suggestions


Kernman   

[helotaxi]

Ideally cleaning from the breech, you want to use a bore guide.  It serves two purposes: 1) it keeps the cleaning rod from touching the bore and scratching the rifling, 2) it keeps the rod from wearing the leade.  Kick up a burr at the first place the bullet touches the rifling and the chances of getting good accuracy are out the window.