Yes there is a portable mg42, you have to use goat mod it's in the gameplay mod page here, u have to drop your primary weapon and press e at the mg42, but u can't use the mg42's regulary, oh and press 4 to bring it up and you can shoot.
hmm i got ck's one on my pc ut it wouldn't work (plus my pc is delapidated) and i tried making my own over a 2/3 month period, couldn't get the model to appear properly it came out upside down and started doing weird things when you ran around with it. worked perfectly ok tho the model was just fubar. wait for the sdk, it'll make it easier