Weapon Switching "Blend Pose"

Hi,

I have a problem, my character blueprint contains blend pose by enum to switch state machines according to equiped weapon. This works very well, but now I want to add a weapon switch animation and this is were problem get started - when I pressed 2 on my keyboard, my animation state change from BASE to PISTOL and I play the “Montage Play”, but it snaps between changed poses, it looks very jaggy. Anyone have an idea how to solve this? How you setup your weapon switching animations?