Trying to run a macro to sort and remove duplicates from entire sheet

Hi, currently use this macro (see below) but occasionally I have more rows than 842. I could increase to 10000 and this would work but looking for a more automated macro that will automatically remove duplicates from all rows i.e. a macro that works out all rows.

Sub copyTab()
'
' copyTab Macro
'

'
Cells.Select
Selection.Copy
Sheets("filtered_data").Select
Range("A1").Select
ActiveSheet.Paste
Columns("A:A").Select
Application.CutCopyMode = False
ActiveSheet.Range("$A$1:$J$842").RemoveDuplicates Columns:=1, Header:=xlYes
End Sub