3 charts, 165-220 BPM. Each one is read from a real score: play it along to the record, slow it down, or take the practice course under it.
3 kirszniak drum parts are transcribed here, 524 bars of music in total. Every one of them is a chart read from a real score rather than a tab somebody typed out: the notes are where the score put them, the tempo is the record’s own, and the page plays the recording underneath while you read.
Nothing here asks you to play it at full speed on the first pass. Take any chart down to half tempo, loop the four bars that will not come clean, and bring it back up. 3 of these 3 songs also have a practice course under them: the part broken into the few things actually different about it, one at a time, ending with you playing the whole song against the record.
A good place to start is "bdm" at 165 BPM, the slowest of them, or "jakiś taki death metal" at 148 bars, the shortest. Sheet music, tab, MIDI and MusicXML download from every chart if you would rather read it away from the screen.
3 kirszniak drum charts, each read from a real score and playable along to the record in the browser. 3 of them come with a practice course that breaks the part into exercises and takes each one up to tempo.
Tempos here run from 165 to 220 BPM. The slowest is "bdm" at 165 BPM, and the shortest is "jakiś taki death metal" at 148 bars, which makes either a reasonable place to start. Every chart also has a simplified version with the hi-hat pulled back and the fills written as eighths on the snare.
Most often C# minor and Eb minor.