My Joseph Lang is a "peninsula" lock because the back lock plate touches the action bar. This gun was built in 1866 before Stanton patented the rebounding hammer in 1867 but I really like the non-rebounding hammers because they can be easily cocked in a single sweep of my right thumb when hunting quail over pointing dogs or shooting clays. Non-rebounding hammers require special handling but I've shot over 5,000 nitro loads through this gun in 5 1/2 years without any issue.