My grandfather Adolph Schwintowski was in Prussian Army Artillery. We had a certificate with his picture on it, very delicate and cracked. I don't have the dates because in one of my moves while in the navy it was lost. Still hurts. He was born in Krotchin and migrated to United States about 1893 we have his Prussian passport from Kingdom of Prussia.
Is any record available about his service?
This is extremely unlikely. A lot of of records were destroyed when the Prussian military archive in Potsdam burned down in 1945. Except for some Reichsmarine (navy) records, almost all individual documents from the Prussian army are lost. Depending where you ancestor lived when he was drafted, local muster rolls might be available from local archives. Photos might give a clue about the unit and garrison.
Please see also Finding information on German soldiers from World War I and World War II
