Loading 50 round ProMag drums?

[originaldrdoom]

I hope this is the right section for this question. If not, I apologize in advance.

I recently scored a Ruger 10/22 with Chicago conversion. It came with 2 ProMag 50 round drums.




My problem is: how in the world do I load these drums? Either there is a ton of tension on the spring inside the drum or I must be missing something. I can only get 2 of the CCI rounds loaded comfortably but that's it.

Any ideas, tips, leads, or video instruction would be more than appreciated.

 

[USAF_Vet]

I'm not sure if it loads like the Black Dog drum mag, but there are some Youtube videos that shows how to load them.