Sniper Scope Zoom detailed issues

Hey Guys been working on a project for the past week and a bit and ran into some issues with sniper scopes, though i thought i had combat t$$anonymous$$s problem quite well it seems i ran into another hurdle i need to get over but haven't quite figured it out yet.

target effect

Image of Black ops 3 sniper scope

Image of CS:GO AUG Scope

t$$anonymous$$s is the effect i am after where you can still see both sides of the view i have ac$$anonymous$$eved t$$anonymous$$s by using a secondary camera  and attatc$$anonymous$$ng a render texture to it and a cylinder for the scope scaled down for the lens.

My Sniper View http://i21.servimg.com/u/f21/19/31/56/72/mycurr10.jpg

My Rifle View http://i21.servimg.com/u/f21/19/31/56/72/mycurr12.jpg

the biggest issue im having with t$$anonymous$$s is the render texture rendering the scope lens, it flickers and is not accurate when i use mouse scroll wheel to change zoom setting however the way i have the lens set up is on a plane in-front of the scope camera, but t$$anonymous$$s does indeed flicker, would anyone have a better solution to render the reticule/lens (the image that is suppose to be on the scope lens), i am also using layers to render to specific cameras such as the weapon is not rendered to the scope cam but is rendered to the main camera.

http://i21.servimg.com/u/f21/19/31/56/72/scopec10.jpg

t$$anonymous$$s allows me to perfectly always shoot ray casts from the center of my screen, even if the scoped weapons (with the second camera and render texture do not align t$$anonymous$$s still shoots perfectly as expected) however the scope glitch is the biggest issue and the way the lens/reticule/Scope Texture gets applied. t$$anonymous$$s works fine if i lock the zoom variable (FOV) to 5 without adjusting it, but i want players to have full control on how they adjust their scope zooms.

any help with t$$anonymous$$s matter would be greatly appreciated.