It's the same as all the other "Red Ryder"BB guns. When you cock the lever it pulls back the spring in the Air Piston tube and locks it in place. Another spring forces the BB into place at the end of the piston tube. The trigger releases the spring allowing the spring and piston to slide forward and Air pressure fires the BB out of the barrel.
Not meant to be disassembled
There are 4 variations of the Daisy model 99 BB rifle, not gun. Your best bet is to contact Daisy directly. They offer a free service to evaluate Daisy antiques. See the link below.
There are 4 different variations of the Daisy Model 99, starting in 1959 to 1979. Daisy offers a free service to tell you more about your old BB gun. See the link below
The Model 99 was made between 1959 and 1979 in Four different Variations.
I suggest Crosman Pellgun oil or RWS pellet gun oil.
No published sn data.
It was only made in 1967.
It all depends on which Daisy model 99 you are asking about. 99 Target special: Variant 1=1959, Variant 2=1960-1979 99 Champion: mfg 1967 99 Lucky McDonalds: mfg 1960
Daisy offers a free service to tell you more about your Old Daisy. See the link below.
They were made from 1959 to 1979 in four different variations.
What physical and mechanical condition is it in? That determines the value.
There were 3 different model 99 Daisy's. 99 Target Special; 1959-79 99 Champion: 1967 99 Lucky Mcdaniels Instinct shooter: 1960