How To Attach Rifle to Both Hands?

Hello all, this is my first post.
I am relatively new to Unreal 4, and am having a hard time figuring out how to attach both hands to my rifle.
I am currently creating a 3rd person shooter, and I am stuck.
Below is the first picture of what I see, when I play the current Level

Here is what I see when I go to my Skeletal Mesh for my character

Above, I altered the Skeleton to fit, thinking I could do it that way.
Here is a picture of the Blueprint that I use to Spawn the M4 into play

I can spawn the M4 in on my Right Hand Socket, and need the front to lock to my left hand. I have been seeing the words IK Node pop up, but for the life of me, cannot find a tutorial related to weapons(They are all about feet placement)
If someone could give me some advice, that would be fantastic!
Let me know if you need any more screenshots or information!