this is an excerpt from the marlin website.

www.marlinfirearms.com/CustomerSupport/faq.asp



12. What is the small round black and white dot on the bottom of my Marlin stock?

This is the Marlin "Bullseye". This trademark has been used since 1922 on all Marlin walnut buttstocks. Please note that this is not a suitable place to install a swivel for you firearm. Swivels should be mounted approximately 2 inches from the toe of the butt.