Home Forums Hunting & Shooting Ask The Gunwriters Scope zero shift

Formid, give me the scoop please.

I apologize. I didn't mean to skip over your question.


I can't say that I could put a round count on it. Some go right off the bat and some take a while, but most seem to just slowly slip.


Where I am scopes and rifles are used differently than the way the majority of hunters use them. I think there are very few failures in normal use. If you just zero them and shoot a couple of boxes a year they are generally good. I really haven't had any problems with good scopes losing zero unless dropped, bumped, etc. So I think for the normal hunter, they will never wear one out. Even if the zero gets bumped an inch or two at a 100 yards they will probably not notice until the next year when they check as even out to 200+ yards it will still hit the vitals.

They way I shoot is quite different. The guns get shot a lot. And every trip the zero is checked and measured with no excuses. When you get twenty days of the gun staying zeroed and then suddenly the group is .4 MOA off you notice. On top of this the turrets are used constantly. In five days the turrets might be adjusted 500 to 1,000 times. Again as soon as even a .3 or .4 MOA shift happens it's noticable. Guys are rough on their equipment anyways. I certainly give no quarter to my guns/scopes. I treat them badly because if it is going to fail I want it to fail in practice and not on a hunt or mission. When using gear this way small changes are very noticeable. This is why I/we experience so many more failures.

While I think the average Leupold, Ziess, etc variable is a good scope, and under normal hunters usage they are probably great, when you see so many fail or go down you start losing faith. And when you get a direct comparison with scopes that just simply work day in and day out, the choices become very easy.

I shoot a decent amount (340 yard range is 40 yards from my back door). I hunt the property around my home and all is by foot. My equipment rarely travels either by truck or ATV. It doesn't get knocked around much. It rarely sees hard use, I fall into "under normal hunters usage" class. I shoot my equipment enough to recognize small shifts in zero. The Leup 3.5-10x40 with M1 has served me well under these conditions. However, I have read many times of their failure in hard use and it has been resonating in my mind for a while. I finally experienced such a failure. I'm proud it was on a trip to the (longer) range. Until I upgrade to a scope that has a reputation for working "day in and day out" I will not be comfortable.

Actually, you already have one. If you want something tougher, than either the Leupold or some other tactical, expensive scope might be an improvement.
But the fact is, ALL scopes will shift zero if impacted hard enough. The military snipers know this well. And they use the best scopes that money can buy. But they check their zero, first and last shots often. Simply because of this fact.
Even if the scope doesn't shift with a certain level of bumps and knocks, it can over time.
This isn't the same thing as breakdown from recoil. Again, all scopes will fail in time if shot enough. Especially if used on heavy kickers and with muzzle breaks. You can get some amazing life from some examples, but, as a rule, if you need real recoil resistance, go with a fixed magnification scope.
Another failure comes from spinning the dials alot. Basic hunting scopes aren't designed to do this alot. The best tactical scopes are.
BTW, weight makes little difference in how well a scope will hold zero. Burris made a whole line of extra beefy hunting scopes some years back. They failed a good bit on lots of rifles. Why ? They didn't test their scope designs properly. They have been doing plenty of testing in the last 15-20 yrs and even their cheaper FFII's apparently hold up well. Leupold's toughest scope as far as recoil resistance is their little 2.5X Ultralight. 6.5 ozs. They probably test their scopes more than anyone. Ask the US Army how tough they are. They use nothing but Leupolds. E

Stop. Please. The most failures of any issued sniper scope has been the variable MK4 Leupolds.

Nightforce, Shmidt and Bender, and Leupold have Army contracts.

I've only read that insight from Eremicus several hundred times here. That fact that you have first hand knowledge to the contrary won't slow this down one bit though.

I noticed the 6X SWFA said "OK for 50 Cal", for $300 I am considering it, but there are two things ahead of it for now.

FYI just as there is no point in discussing Moohamed's peccadillo's with a mooslim, there is no point in discussing Loopholes lack of sainthood with E.

I can't get past the oversized nature of the SWFA SS 6x

I had a tough time when I received mine, seemed a bit out of place but, after mounting and cranking on dials for over 400 rounds in a weekend, I don't see the bulkiness any more! This is my 2nd fixed power scope I plan on keeping. #2 is a FX-2 6X36 with a etched STD Duplex.

I need to shoot at longer ranges this weekend with my scope set on 6x to get a feel for it.

A few random thoughts after looking at this thread the past 3 days.Just my own thoughts.

Years back scopes were smaller..."experts" (guys who hunted a lot)did not like big scopes...over-sized objectives invited more bangs and bumps,hung out too far beyond rings and made them more susceptible to bending while stored in scabbards, etc.

Standard advise was have as little of the scope as possible hanging outside the rings,theory being that portion hanging over the rings was more susceptible to bending and banging,and better to have as much of the center of the scope as possible between the rings.

Today we like to see better,shoot farther;bigger objectives are brighter and variables provide more power. It is said they are "tougher" (not really sure about that part). We match theses big scopes to short actions,leaving lots of scope hanging out the end.

We fall all over ourselves to get the lightest mounts possible(more fragile?).

No criticism against the OP and just making an observation, but it isn't much of a surprise when a scope does not survive a rough ride in the pick up.

Take a look at Formidilosis' set up....heavy duty base and rings, cross slot format,smaller scope known for toughness.,mounted with as little as possible of the scope hanging out there.Less likelihood of getting banged around,and able to withstand the knocks.

A 6x36 mounts up this way on a long action,plus it's a fixed power.Ditto for things like 3X and 4X scopes......I don't think it's an accident that those scopes have a reputation for integrity if mounted properly.Maybe not the premium in optics, but mechanical reliability trumps the view any time.JMHO

Bob, I agree with you rationale in general, however, in this case, the scope that did not survive the ride was not a big scope. The Leup 3.5-10x40 is a tidy package. Neither did it have anything to do with the mounts (I guess that could be debatable).

Good post as usual Bob. Lot's of good stuff, but one of the key things you mentioned, and I especially agree with, is the "if mounted properly" assessment. Obviously it pertains to variables as well.

JG: Sure...stout mounts are important and light weight isn't always "everything"....

For a half-assed example,take a look at Warren Page's 7mm Mashburn,pictured in the Heritage Auction add in this month's Rifle magazine.

Notice that the 4X Kollmorgen Bear Cub is mounted so that the front ring is clear up to the objective,and Art Mashburn fitted a rib for mounting the front ring so that the scope was supported far forward as possible....nice metal work and functional.

Page used to dote in print on that rifle holding constant POI under all conditions,and it killed over 475 BG animals on several continents.

Not suggesting we all go back to 4X scopes , but there are some good scope mounting lessons there.

ct: Well by todays standards,I guess the 3.5-10X is not a "big scope"...and I agree....but it has taken a few years for me to come to that conclusion

Might be a generation gap thing but to me a 3.5-10 is "big"

Pains me to admit the vast majority of my BG animals have been killed with a fixed 4X.... This is largely due to a severe personality disorder.

I suspect your scope just got rattled a bit too much,and took a different setting in the adjustments.

I think scopes were better built back in "the days" Bob. I remember an old 2-7 (friction adjustments) Leupold I had and that thing never lost zero.

RD everyone cursed those damned friction adjustments...."didn't move and adjust easily" they said.

I struggled with them myself but always figured, they were tough to move because Leupold made them that way, on purpose, so that once set,they wouldn't move!

Mornin Bob,

First I think we're in the same generation, however I didn't get started deer hunting till '72. So maybe it ALSO has to do with when & where one began hunting.

Second, I can't remember 1 deer I've killed with a 4X.

Third, 'seems' like the personal thing might be right.

They sucked arse for accuracy, but they did stay put once you burned up enough ammo to get them zeroed. I'll give them that. I think though, that Leupold's in general have fallen off in quality control.

The size and weight have been the main thing keeping me from pulling the trigger on one of these. Testimonies like yours might make me reconsider. I'd be adding 5 oz of scope weight...

John