Home Forums Hunting & Shooting Ask The Gunwriters how much bump will cause a rifle to lose zero

I'm trying to get a feel of just how much, or little of a bump will effect zero on a rifle with scope. Some examples of actual changes of zero and how much of a bump caused it would be helpful. thank you.

Depends on multiple variables, such as scope, mounts, bedding, etc.

Tasco, almost imperceptible bump.
Bushnell pretty good bump.
Leupold hellava bump.

Lots of variables to consider here. Rifle, scope and mount will change things. How the rifle falls changes things, too. The surface it's dropped onto would likely matter most of all. The worst zero shift I've ever experienced would have involved a 742 with see through mounts and a k2.5. The rifle was slung, I hit a slick spot on an uphill gravellish path, and fell over on the rifle. It went from a solid 100 yd zero to no one knows. There wasn't a sheet of paper in camp big enough to get shots on paper even at 25 yds.

Saw a rifle dropped hard enough to dent scope turret cover, no effect on zero.

Impossible to answer correctly.
Many bumps that would worry you,
don't cause the G-forces of a decent rounds recoil.

Then you have the springs that maintain the adjustments and the interface between
The turrets and internal tube.

Age, recoil cycles, adjustment cycles will all come into play.


I have had bedded synthetic stocked rifles, with well mounted decent lose
zero, for no apparent reason. Who hasn't?

So, even if you were to bump your rifle, and it changed zero, could you definitively
say the bump caused it? Or had the darn thing shifted before?


I never used one, but I thought the Burris posi-loc system was a great idea.
However, it hasn't taken the world by storm.

Not very scientific, but I will say that if you lose your footing, and somersault and then tumble about 80 or 90 feet down a steep, rocky slope ( losing your rifle off of your shoulder on the first or second bounce), your rifle will definitely need to be sighted in again. It may also need some cosmetic attention, especially if it happened to land muzzle first on at least one bounce, and the scope will likely need to go back to the manufacturer for service.

Maybe not, I’ve fallen and dented the front objective bell without lose of zero. I’ve also experienced loss of zero without dropping or bumping a scope. It all just depends.

I dropped an old Redfield real hard once, something came loose inside, sent it back, they sent a new one.

You can't even begin to quantify a situation like this. I will say I have a M700 that was my only hunting rifle for 20 years that I hunted HARD (at least one horse wreck that I can recall). Weaver rings, Leupold Vari-X II 2-7 Compact didn't change zero ever.
Also my varmint rife with Vari-X III 3.5-10x50 in windage adjustable Leupold mounts once fell over in my garage on the concrete floor. Never moved a bit.
You just never know.

Just riding around on a four wheeler with the rifle bungeed on the back in a canvas case knocked out an old Redfield and a newer Leupold. Weird thing was I tested them and they seemed ok only to miss easy shots with them later, wandering zero? Now they go on the front in a hard case.

A good scope like a Leupold (contrary to the fire's curmudgeon contingents opinions) can take quite a beating. A cheap scope can go off just from riding in the trunk on a bumpy road. Drop one from a tree stand and it is back to the range to test or you are just wasting your time hunting and risk wounding an animal.

Ruffed grouse,
This is an impossible question to answer with any certainty. Too many variables!

Like many here I've found normal use with mid to low quality scopes and mounts, even if properly mounted, result in more POI shifts than quality gear being bumped.

I can think of no instances that I have slipped and fell, knocking a good scope and ring system so hard that it wasn't zeroed any longer. I've had horses loose their footing and roll with a rifle in the scabbard, which held zero. I've put some noticeable dents and scuffs in the ocular bell of scopes when I slipped and fell on some rocks, which also held zero. Maybe I have just been lucky but you gotta knock them pretty damn hard if you got good equipment and they're mounted properly.

I slipped and fell and broke a scope one time. Eyepiece was at an approx. 15 degree angle to the rest of the scope.

When I fell from the stand a few years ago, I broke the stock on my 30-30, but the scope was ok. I after I repaired the stock I figured the scope needed to be zeroed, but I was wrong. The scope was still shooting 2" high at a 100 yds.

Have had that experience myself. Gun babied, no falls, drops, not even a rough ride in the truck, site in fine, missed easy 200 yard shot low and to the right. Checked zero at 25 yards barely hit the right lower corner of a 8.5x11" sheet. Erector assembly took a dump.

Had a bushnell 4200 on a rifle. We were driving through the woods and a tree ripped it out of my hands and out the window.. The objective end of the metal was/is digned up; but it never lost 0. Still shot an elk with it later that season... Cant argue with that.

Get a NightForce.

I had a scope that would loose focus with every shot, but still held zero.

Had a wire reticle snap, apparently due to too many rounds of heavy recoil, but three of the four crosshairs were still in place in the center--and the scope was still sighted-in.

Last fall elk hunting, I slipped on some ice and while I was falling, I lost my grip on my rifle and it sailed out of my hands and fell on some rocks. The barrel got a few rock dings and the scope rings got some too. Scope was a fixed 6x Leupold mounted in burris/ weaver type mounts. When I rezeroed the rifle it was off by about 10 clicks.