Years ago I purchased the special edition Vepr AK 7.62x54R from Atlantic Firearms with the red wood SVD stock set.  The page for that rifle doesn't exist anymore, but here is the stock: https://www.atlanticfirearms.com/products/vepr-red-wood-svd-style-stock-set

At the time, I purchased a POSP 6x24 Vepr/AK style mount and mounted it on the rifle.  I've had a few issues with the gun the couple of times I've tried it and it's basically sat in the closet because I didn't know what I was doing, so now I am determined to correct them.

First, the iron sights are useless with this stock, even with the lowest cheek weld possible, the rear sight sits so low, you have to max the elevation to 1000m (I think max) and it's still a little low for 50-100yds.  I'm not too concerned with this, as I want it to be an optic rifle anyway, but I figured it was worth mentioning in case it's causing other issues.

Second, with the POSP mounted, while sighting it in, I got the elevation perfect, however the windage was not even close to paper at 50yds.  I moved to maximum windage on the POSP and  at best was grouping around 8" to the right of point of aim.

I have little to no experience with the platform or optic and I know the Russian optics are wonky with backwards adjustments.  I do notice that the optic sits quite noticeably left of center bore on the rifle.  I have also tried it on my DDI Bulgarian AK and notice it sits way left of center bore on that too.  I've always hesitated to throw more money at the issue and get a new optic and/or nice mount like an RS Regulate.  Am I correct in assuming that this is likely an optics issue?  With the side mounted style AK mounts, is the optic supposed to sit off center like that?

Most scopes will sit just a hair left of the bore on AK's unless it goes completely over the top of the dust cover and sits center. If your truly out of adjustment in your windage then your scope or scope rail isn't straight with the bore. Basically you can kinda search on google about people talking about shimming their scopes, filing on their scope rails/mounts to fix this. Everything i just said sounds like a pain in the ass and im glad i didn't this issue with my PSL.

I would shim my scope before taking a file to anything. I'm not sure if TWS makes a dog leg rail you could use if you wanted to go that route or not.

Thank you, I hadn't thought of that issue.  Since it's a crap POSP scope, I was planning on eating the loss and trying a RS Regulate mount/rail with a scope I already own and know works.

RS makes a solid mount and will probably be a better option anyway since you can have your scope mounted directly over the top center of the rifle and have a newer optic.

The windage has further adjustments

Loosen but do not remove the two screws

You can move the top black plate independently of the silver drum

The top black plate moves the reticule inside the FOV. The silver drum is the BDC or windage marker

Total range of motion is typically 1 full plus 3/4 more turn

If you get it zeroed tighten the screws with the silver drum set on zero and you're GTG

The POSP is a copy of the PSO and is designed to take rail variations between rifles into account

If that's his issue of just not knowing how to zero the scope then good but i figured that was just common knowledge with how easy the internet is to use.

But if his scope is maxed out to one side kinda like this pic then what?

If it's maxed out to one side after loosening the screws but POA is zeroed to POI, then it's considered good by combloc standards even if the reticule is all the way to the side of the field of view

If he can't get it zeroed after loosening the screws then it will be time to investigate shimming the base of the POSP. The 4 screws can be removed to take the base off the scope and he could experiment with slivers of an aluminum can on the front two screws to push the objective to the left, or on the rear two screws to push it to the right

Alternatively he could try to file on the base itself but before I did that I would check the scope against a couple different rifles, and check a couple different scopes against the problem rifle to be sure it's the scope or the side rail