Looping A Copy / Paste Formula?

I have a spreadsheet that calculates a rolling percentage of a row of numbers. The formulas are contained in two columns, J and K. The first row is a header row, and the formulas repeat every 52 rows (e.g. J2:K53, copy paste those cells, re-paste at J54, then J106, and so on. Because I don't know how to loop, I've had to manually right in the paste every 52 rows in my line of code. Surely there is a way to have this cut down and to actually stop when there are no more rows of data. For the record, this continues on manually until 80,000 because I don't know how to stop it at the last row.

Code:
Sub CopyPasta()
'
' Copy_Paste_52 Macro
'
'
Range("J2:K53").Select
Range("K53").Activate
Selection.Copy
Range("J54").Select

[code]....