As you might already know, after selecting the armature, going into pose mode, opening up the Dope Sheet and then Action editor:











the delta animations will look like this:











Go to base_idle animation, and copy all keyframes, then go back to delta_iron and paste them:











Do the same for foregrip animation, go to first frame of foregrip_fire for example, copy keyframes, and paste them to delta_foregrip. Yes, it's pretty easy.

For ironsight animation, we will need to adjust it more. Turn on ortho view (Num5) and then press ctrl+Num1. Select all the bones (A):











And move them so that the tip of front sight is located at the center of axes. You might want to turn of wireframe (Z) because the front sight might not be visible from that view. We'll fix this later.

To save keyframes either press I and select LocRot every time you make change in pose mode, or turn on automatic keyframing in the timeline window.










Now select only A_Muzzle_Ironsight bone and move it to the center of axes too.










Make sure that it's aligned properly by zooming in:










Now copy the keyframes from delta_iron and paste them for all other optic delta animations. It will save us some work later.

All that's left to do now is to rotate the whole armature so that we get an ironsight picture we want. For easier alignment, it's recommended to place the 3D cursor at the tip of the front sight and then set pivot center for rotation to 3D cursor.











Press R and then X, and rotate until you'll get the sight how you want them.











You see that the A_Muzzle_Ironsight bone is misaligned after this, we need to fix it back to its place.

Just rotate it back (you can see we rotated the whole armature -0.5 degree, so rotate it +0.5 degree). Place it back to the center of axes.











Now that the irons are fixed, we'll proceed to fixing optics animations.

I have prepared the required files here[drive.google.com], or you can extract, decompile and import them yourself from Insurgency game files.

Open up default_weapon_upgrades.theater file to find out what weapon uses optic model of what size. It's important because if you'll import optics armature of wrong model, the sight will not be zeroed in.











Go to File -> Append and open up aimpoint.blend. Open Object folder and import a_optic_aimpoint_reference_skeleton.











It will look like this after import:










Delete smd_bone_vis (what the hell is it anyway?) and align the whole skeleton (press G, Z in object mode) so that A_render_reticle is at the Z0. It's good to switch to side view (Num3) so that other bones won't be obstructing the view.









Switch back to front view (Ctrl+Num1) and in pose mode select all the bones of weapon skeleton.
Move the whole pose down along Z so that the both A_Optic bones are in the same position.









Zoom in and align both bones precisely.









You may have noticed that the A_Muzzle_Ironsight bone is misaligned again. So move it back to the center of axes.









And we're almost done, last thing you might want to adjust, especially for scopes with magnification, is the position of whole armature at the Y axis. Magnification of scopes ingame is dependent of the distance of A_Optic from the origin point/camera.










And we're done, just repeat the whole process for other optics too. If the laser dot or point of impact is misaligned, check the location and rotation of A_Muzzle_Ironsight bone, it shouldn't be rotated and always should be at the center of axes.

Also check if the idle animation is the same as base_idle.

Just add subtract "idle" 0 for every delta animation. Crowbar adds this line these days anyway (only there's "menu" and not "idle").