I took my new Zenith Z-5RS out to my (not very) local outdoor shooting range on Monday for a shakedown run. I mainly wanted to do a function check and adjust the rear sight, if necessary. I brought along a slew of different types of ammo from my hoard, to see what the pistol would work with.

I did almost all of this shooting off of a sandbag, resting on a bench, to eliminate any "shooter error". The initial groups were fired at 25 yards, and the sight-in ammo was Winchester 9mm NATO 124 grain. This range uses old wooden pallets for target backstops, so I stapled up 8 bullseye targets and worked from left to right. The first group of 5 rounds fired hit the left edge of the 8.5"x11" target paper, so I knew that a windage adjustment would be required. Over the next four groups, I dialed in the windage, and the sights are now adjusted. The problem is that the rear sight is maxed-out to the right, to the point that the sight locking screw is almost touching the rear sight's adjustment slot. I verified the sight setting by firing four more bench-rested groups at 50 yards, and other than hitting somewhat high (as expected at that range), the windage was still good.

I am wondering whether or not the maxed-out windage is a "problem", or if the sights can be zeroed, it is within specifications.

The pistol worked flawlessly for the 100 rounds I ended up firing, and is actually very accurate. I didn't do the full 350-400 round break-in that I had planned, because I wasn't sure if the windage issue was something that should warrant a repair or exchange of the pistol. Plus, I was a bit bummed-out by this point...

I should mention that this pistol is actually Zenith Z-5RS NUMBER THREE (!!!) that I have had pass through my hands, in an effort to get ONE good one. The previous two had obvious manufacturing issues, so I didn't even fire them. This Z-5RS looks pretty good; the sides of the magazine well opening are almost parallel, the receiver's push pin bushings are straight, and the trigger pack doesn't bind on the receiver's shelf, unlike the previous two pistols I briefly had. The included MKE magazines don't fit very well (two fit loose with over 1/4" fore/aft wobble at the bottom, while one is extremely tight with no fore/aft movement), but I bought some POF magazines that do fit well. The 3-lug fitting on the barrel isn't perfectly aligned, but 3-lug accessories actually fit, unlike Z-5RS #1; #2 was so obviously messed up in other ways I didn't even try. The point of this paragraph is that I am worried that if I send this pistol to Zenith for replacement, I will get another Z-5RS that has worse issues than a canted rear sight. The repair process for fixing a canted front or rear sight sounds pretty brutal, and might do more harm than good, especially if it is done by anyone less than a Master.

I only bought a Z-5RS with plans to "build" it into an SBR, so there is the added cost/wait/hassle associated with that as well. I only want to invest the time and money to SBR it if the pistol is really worth it.

So, what would you do? Live with canted (but correctly set) sights, or go for Z-5RS number 4 and hope for the best?

If it's zeroed, I wouldn't worry about it. My RS has a slightly canted rear sight base, but it's something I can live with since it zeroes okay. It's annoying, especially given the price I paid for it, but it is what it is.

I just finished examining the sights my Z-5RS. With the bottom of its receiver sitting on a flat surface, and while sighting down the rear of the receiver, both the front and rear sights looked straight to my "Number Two Calibrated Eyeball Gauge". Since shooting the thing proved otherwise, a different method of checking was required.

Next, I looked through the rear of the receiver and compared the angles between the top flat of the barrel trunnion and the mounting flat on the rear sight base. Checking it that way, I could tell that the two flat surfaces were not parallel. The rear sight base is lower on its left side than its right when compared to the presumably straight barrel trunnion. That direction of error is correct for a rear sight base canted to the left, with the resulting rear sight windage pushed to the right to compensate.

So it looks like our MKE pistols have the same problem. Or "problem", as I'm trying to convince myself to view it.

What's the date of manufacture on yours? Mine is January 2016.

Mine was made in March 2017, so it was made in the aftermath of the attempted coup in Turkey. I'm sure that the brutal living conditions in post-coup attempt Turkey are making "QC" a very low priority for the employees running the machines at MKE.

Wow! 3rd lemon! I admire your staunch determination and loyalty to Zenith/MKE, but I would've ejected already. On the flip side, if it's zeroed and you can live with the canted sight, then shoot on and never look back. If you're  like me, when I spend 2-3k on a gun, at the very minimum I expect the damn sights to be welded on straight.
There's such a hunger in the roller lock 9mm carbine market for a solid QC under 2k player to enter and fill the void. I don't think Omega or Zenith has their products dialed in yet. There's been numerous threads on QC issues for both.
I will say this for both manufacturers though, at least with the threads I've read, the customer service for both has been very good in resolving the issues  or getting a new weapon out to the customer and I applaud that. Most of the major player manufacturers customer service leaves a lot to be desired.

Yeah, I feel like it's an easily corrected issue that nevertheless persists. Not sure why they can't take 5 more seconds to make sure the rear sight base is centered before welding.

When i received my Omega mp5, I noticed the rear sight was slightly canted to the side. I gave omega a phone call about it and talked to the owner, who then provided me photos of a mp5SD he had in his safe, with the same issue of canted sights, however the gun was able to be sighted in, I handled a few HK mp5's at knob creek and most of them had some degree of cant to them, I'm convinced just like AK's if it can be sighted in, its in spec.

As the sights are welded on, i believe they could all start straight, but during welding as metal heats and cools, they may be pulled slightly off being completely straight.