I found a video on youtube showing the loading of a Vickers machine gun (The Parabellum was closer to the Vickers than it was to the LMG08 or LMG08/15) and it clearly showed the belt being passed through the onto the feedplate with the right hand, and then held with the left hand while the charging handle was cranked twice. Based on this, I believe the loading procedure for both guns was.
Changing Magazines on Lewis gun.
1. Press catch in centre of magazine and remove empty mag.
2. Drop empty mag on cockpit floor for collection later (a)
3. Unstrap a new 97 round magazine (4kg)
4. Making sure the notch in the magazine is pointing to the right, fit the magazine to the magazine post on the lewis gun.
5. Cock the gun.
6. Commence firing.
(a) Complaints from DH4 gunner that the empty magazines were jamming auxiliary flying controls mounted on the gunners cockpit floor indicates this was standard practice.
Changing Spools on a LMG14 Parabellum
1. Release and remove the empty spool from the gun
2. Drop empty spool on cockpit floor for collection later (??not sure if the German did this or just threw them overboard as they're much larger than a lewis drum??)
3. Unstrap a new 250 round spool (~7.5kg) (b)
4. Making sure the spool is up the right way, clip the spool into its mounting.
5. Pull 20-30cm of belt out of the spool
6. Feed the end of the belt into the right side of the Parabellum with the right hand until the first round is lying on the feed plate in line with the barrel.
7. Now holding the end of belt with the left hand, cock the charging handle twice with the right hand.
8. Commence firing.
(b) The Typenprufung (19 June 1918) for the Pfalz D.XII give the weight of 1000 rounds in a two hole webbing belt as 25.6kg. This means a 250 round belt of the same would weight 6.4kg. The steel spool itself with convered slides would have to weight at least a 1kg gived a total weight of approximately 7.5kg. Does this sound about right?
If anyone has more definative information, I'd love to be proved right/wrong.
Tim