Does marking the turrets after zeroing do any good?

If your zeroed in at 50 yards , then change the zero for 100 yards , then it would be useful to return to the 50 yard zero. This is in the short term, a day or a week. A year later, not to useful.

Because-

Some scope adjustments are not repeatable on low cost scopes.

The point of impact may change with different ammo.

After cleaning, different torque on the action screw.

A wood stock may absorb moisture or dry out.

Some target rifles will retain* zero better over a years time. Depends on the type of stock, bedding , how and where is stored.

* made spelling correction- remain changed to retain

IME, the marks help you to get on the paper, when you are going to try to re-zero,
but they can't be outright trusted. Re-zero to certify the marks are still good.

If the scope doesn't hold zero over time, either you've changed ammo, changed environment, shifted your mounts, changed your hold (parallax error, shooter follow through, etc), or your scope is busted. After your "veteran" sighted the rifle, did you confirm impact as well, or just trust his zero? If you're holding your optic off center, differently than the other shooter, you might be experiencing a parallax error. If you're jerking the trigger this year after laying off for so long, but weren't jerking last year, you'd experience a POI shift. Changing ammo is pretty straight forward - different loads will have different POI's. Changing environment can shift your POI as well.

If the scope is slipping zero, then it's busted and need replaced. Period. If your mounts are loose and shifting, then you need to tighten it.

I have a scope with "target" knobs on the adjustments, no covers. I can imagine these knobs being accidentally changed when casing/uncasing the rifle so,I put reference marks on them.

The old timer knew what he was doing. He assumed you were not going to take the scope off and on. Depending on the scope and the mount, the zero's are stable. I regularly remove the Redfield 3200's, and Lyman Super Scope on my target 22lr's. Pictured is my Rem M37 with a Lyman Super Scope.


The barrel dovetail system and scope mounts are extremely repeatable. I do have to make elevation and windage adjustments, which is why you get sighter shots, but my zeros are all different at every range for elevation, by a couple of clicks, and windage zero depends on the wind.

Pictinny rail mounts are very repeatable with a good scope. This monster scope comes off the rifle and goes into a different safe. Shoots close enough on re installation that only a click or two is needed in the sighting period.




Now with sporter scopes, you take the things off their mounts, depending on the mount, it may line up straight or not. I never had a scope line up the same with Redfield mounts, Always had to go back to the range, shoot the thing, to establish a new zero if I took the scope off. This rifle has an antique Weaver 4X, I am afraid to make any changes when shooting for group size, as with a sporter scope, the group may move, or not move, or won't move till two shots later. The things may crazy move where you get a bullet way the heck out. This group is low and left, but that is OK, the rifle shot a 5 3/4" 17 shot group at 300 yards. I did mark the 100, 200 and 300 yard settings on the turret.





This rifle, also a 30-06, but with a 6X Burris sporter scope



I established a good 300 yard zero back in Feb and I marked the 100, 200, and 300 elevations on the turret. You can see the white fingernail polish on the top and side of the tube.


Just shot it last week, using the markings for my 300 yard zero, and this was the first shot, cold bore zero at 300 yards, after examining the wind drift through my spotting scope. It was so pretty I had to take a picture:



So heck yes, keeping recordings, marking the scope, or the stock, is very important if you expect to be in the center. Also is very important is knowing your equipment. Does your scope line up again after taking it off? Are elevation and windage changes repeatable? Or does the scope give a crazy point of impact after an adjustment? Only way to know this is by shooting the things, not reading the opinions of internet keyboard commandos.

There are a ton of variables here, many noted above.

First off, .22lr ammo is no where near the same. Further, price does not always reflect better accuracy; each rifle "likes" a different brand.
I can put Eley TenX in my Nylon 66, but it will be nowhere near the POA through the scope (unlike "plain" PMC FMJ). The "zero" on the scope would not change at all, but the POI would change with the ammo.

Then, there are the scope mounts. Often, the skinny little rails on .22lr rifles are less-than great. My Nylon 66 hated those; but has been good with screw-down mounts. This can affect "zero."

And, as touched on above, the quality of the scope can matter, too.

CajunMan89 said:

I'm still in the learning stages of scopes and such, so I have this question. I once had the Bushnell scope on my .22 zeroed with the help of a veteran. After he got the scope zeroed, he marked the turrets with a permanent marker.

My question is, does this really do any good? The next year, the scope was off, and even though I lined up his marks, the scope was still off the bulls eye.

Click to expand...

A different ammo will change point of impact.
Even a different lot of the same ammo will shoot different.

RESETTING THE ADJUSTMENT SCALE RING
The less expensive scopes, where the adjustment is done by removing the cap and turning a slotted screw with a coin to adjust, have a ring(usually silver) with hash marks and a "0".
This ring can be turned to line up the "0" with the screw slot, and in affect "mark" the zero.
This is explained in more detail in most instruction manuals that come with a scope.
On scopes with exposed turrets check the manual for aligning the turret zero.
Here's the instructions for Bushnell:
http://www.bushnell.com/global/customer-service/product-manuals

Do it all the time, especially with 22's. I zero at 50 yards, but by trial and error have figured out where to move the dials for a 100, 200, and 225 yard zero. When I go to the range I shoot at all 4 ranges and adjust the turrets as needed. There is an adjustable dial on my scopes to mark zero with. I have it aligned for the 50 yard zero and have memorized the number of clicks needed for longer ranges.

It is easier with a scope made for this, but the principle is the same.

A little White Out works fine but more of mine are coming with resettable turrets these days. Lots of good info already and wanted to add that if the action need not be removed from the stock then leave it be and if it's shifting but the optic is good, have it bedded.