Don`t shoot the messager but I do believe from accounts there was no real MP44 sling manufactured for the gun (If they were probably in limited number). It would appear that they used the kar 98 sling (That is what I have attached to mine so lets hope so). They are quite easy to get either from epic or ebay
Good hunting
You're absolutely right, Gordon.
You've got nothing to ein, zwei, drei, vier
MP40 had a dedicated sling.
K98 used a standard rifle sling which all subsequent German rifles used. (MP44 G41 G43)
Good repros are available from such as sof and rau. We bought 30 from sof last year for our real steel ones. They are standing up to hard use.
LOOK! I ham now four meggle man!
A001
Ironically enough SoF do have an Mp44 sling listed. It just happens to be exactly the same picture and price as their K98 one, although I'm surprised they aren't asking more. 
The hop up is the same type as an m4 hop, If you want to buy one get a tokyo marui for best range and accuracy.
im using the kar98 sling for mine and its good. the hop is indeed an m4 type hop. although its just an agm gun, my 44 shoots perfect and feels very good quality. the only problem i had was that the cocking bolt used to touch and move the hop unit so i had to put a small screw in the side of the gun to stop the bolt moving all the way forwards and knocking the hop out, after that it was fine. just need some quality mags now as the agm ones are s-h-i-t.
