Marksman made several models. Which one are you asking about.,
go on the computer and scan the words 'marksman air pistol' ...............
marksman
see the link below for the owners manual. The Marksman Repeater is a 4.5 .177 caliber pistol not a 5.5 .22 caliber pistol.
see the link below
The Marksman Repeater doesn't use a C02 Cartridge it a spring operated pistol
To get an answer you will have to state the condition of the pistol & is it still working?
See the link below
See the link below for reassembly.
which Model are you asking about
Marksman doesn't list the cocking effort but believe me it's very little. The pistol only fires a 220 FPS and that is slow.
Starting in 1977 to present
Check YouTube for Marksman Repeater, I have found several that show you how to take it apart and put it back together