My gt-grandfather, Charles Edward McKenna held the rank of Quartermaster Sergeant in 6th Company 4th Batt.IY.
The only information I can find is a transcription from Findmypast.
I cannot find attestation,service or discharge records.
What I would like to know is how long would he have had to serve to reach the rank of QS.
Is there a chance that he served with another regiment before the IY and if so how would I find out.
Would be grateful for any help or advice.
If there is no folio available on line, a manual search in WO128 at Kew would be the way to go, I would certainly expect it to bare fruit, although it is not a complete series, if his papers have survived, they may give you an indication of the period he attained his rank.