Four more persons were sentenced to jail terms here Friday and today in connection with the bribery and corruption scandal in the General Service administration.

They had all pleaded guilty to charges of conspiring to defraud the government stemming from a scheme in which they claimed to have received office supplies that were never delivered to the GSA stores.

Samuel Lousis McClain, a 46-year-old Hanover, Md., resident who was one of the civilian purchasing agents at Fort George G. Meade, was sentenced to 20 days in jail and two years on probation. Prosecutors, who had recommended 30 days in jail, said McClain accepted a bribe of a $700 riding lawn mower.

Roger Dale Wilt, a 30-year-old District Heights resident who was the manager of the GSA store at the Housing and Urban Development building, was sentenced Friday to four months in jail and eight months probation. Prosecutors, who recommended a six month jail term, said Wilt accepted $3,000 worth of bribes.

Eugene Proctor, a 50-year-old Washington resident who was a civilian purchasing agent for the Navy Bureau of Medicine and Surgery in Arlington, was sentenced to 60 days in jail and a $250 fine. Prosecutors said he accepted about $1,000 worth of bribes and had recommended the 60-day term.

John B. Swindler, a 36-year-old Upper Marlboro resident who was the manager of the GSA store at the Lafayette Building in Washington, was sentenced to 13 months in jail. Prosecutors said he was one of the GSA managers more deeply involved in the scheme and had accepted $12,000 worth of bribes. They had recommended a jail term of 15 months.