Rifle Scopes How much adjustment is normal to zero (Fixed)

[mwinter501]

Fix is in post #16


Hello all,

I just recently bought a new high-end scope. It replaced the Gen 2 Kahles that I had on the rifle already. The kahles didn't take a lot of adjustment to zero, and I mounted this new one in the same mount on the same rifle without changing anything else. When zeroing the new one, it took me over 18 mils to get it to zero and is now constantly on the second revolution. I have enough adjustment to get as far out as I would need, but it being on the 2nd rev limits some of it's features. The mount is a Spuhr with 20MOA built in, so I really wasn't expecting to have to use so much of the scope's adjustment. Is this somewhat normal or should I contact the manufacturer? I haven't owned too many magnified scopes, so I'm not sure whether it's something I should be concerned about or not. Any and all help is greatly appreciated.

 

[Kruger21]

Can't help with advice unless we know what High End scope your talking about for a start!!

 

[tt123]

Was it centered to start with?

 

[digrazir]

The scope should not be on the second revolution...Loosen your evaluation turret, like when you were zeroing your rifle at the range. Rotate a full 360 degrees and you will be back down in first first revolution..it seems to me when you went to zero, you turned your turret to the wrong zero..not sure what scope you have, but it is a mistake easy enough to make if it is one of the newer S&Bs. Ask me how I know. Ray

 

[mwinter501]

Can't help with advice unless we know what High End scope your talking about for a start!!

Sorry, I figured it would be generally normal or abnormal and wouldn't be scope specific. It's on a Minox ZP5.

 

[mwinter501]

Was it centered to start with?

I can't say for sure. I mounted it as it was straight out of the box.

 

[mwinter501]

The scope should not be on the second revolution...Loosen your evaluation turret, like when you were zeroing your rifle at the range. Rotate a full 360 degrees and you will be back down in first first revolution..it seems to me when you went to zero, you turned your turret to the wrong zero..not sure what scope you have, but it is a mistake easy enough to make if it is one of the newer S&Bs. Ask me how I know. Ray

Ok, that sounds easy enough, but that will still only leave me with 13 mils of adjustment. It's not enough to shoot out to 1000 with my rifle. Now, I don't expect to be shooting at that distance too often, but I wouldn't even be able to go into the second rev. I didn't figure that would be normal, especially with a canted mount.

Thanks, everyone, for all of the help.

 

[SubOptimal]

With a 20 MOA scope mount you should be no where near the 2nd revolution. Start over and center your turrets prior to shooting. Chances are, at 100 yards, you should have to dial down a good 3-5 MOA. If you still find yourself dialing up, your mount is backwards. Remove scope and turn the mount around. A Spuhr mount with a reasonable scope height should show about 1/16" difference between center of bore and center of scope tube with the front being lower than the back You can almost eyeball this and estimate height from the center of the bore to the center of the tube, take a little windage to allow for stock variation and measure at the scope tube just either end of the mount.

 

[mwinter501]

With a 20 MOA scope mount you should be no where near the 2nd revolution. Start over and center your turrets prior to shooting. Chances are, at 100 yards, you should have to dial down a good 3-5 MOA. If you still find yourself dialing up, your mount is backwards. Remove scope and turn the mount around. A Spuhr mount with a reasonable scope height should show about 1/16" difference between center of bore and center of scope tube with the front being lower than the back You can almost eyeball this and estimate height from the center of the bore to the center of the tube, take a little windage to allow for stock variation and measure at the scope tube just either end of the mount.

Well, it's a cantilevered mount, so they would have had to machine everything backward for that to be incorrect. Also, I didn't change it from when my Kahles was mounted and never had the issue with it.

There's one part I guess I'm just not understanding. Even if I center the turrets and re-zero, how would that change how much adjustment is needed? Wouldn't I just have to make the same extreme adjustments to get the POA and POI to match?

Thanks again for everyone's help

 

[Kruger21]

Sorry, I figured it would be generally normal or abnormal and wouldn't be scope specific. It's on a Minox ZP5.

As a rule it sounds abnormal to require 18mil to zero. But as someone said earlier its easy to zero a PMII with the 2nd rev indicator visible.
You can fix that by disengaging the turret spin back bypassing the zero stop back to zero in the first rev.
I'm pretty sure the Minox zeros a similar way as does Premier!!
But it still doesn't account for the 18mil needed to zero!?!

 

[mwinter501]

As a rule it sounds abnormal to require 18mil to zero. But as someone said earlier its easy to zero a PMII with the 2nd rev indicator visible.
You can fix that by disengaging the turret spin back bypassing the zero stop back to zero in the first rev.
I'm pretty sure the Minox zeros a similar way as does Premier!!
But it still doesn't account for the 18mil needed to zero!?!

Yeah, that's my main concern.

 

[pell1203]

The Minox ZP5 (assuming a 5-25x56) has a total elevation adjustment of 28 mrad. Have you confirmed you have the full 28 mrad (approx) available of vertical travel? If not, you may have to clear the zero stop.

A 20 MOA base will give you an additional offset of approximately 5 mrad, so in a perfect world, if your zero where to coincide with the optical center, you should be left with a total of 19 (14 + 5) mrad of up elevation. However, since this is an imperfect world you would likely have to use some adjustment in elevation to overcome any misalignment and actually get it to zero. In any case, unless there is something terribly wrong you should have between 15-19 mrad of elevation still left.

My point in all this is, if you started with the elevation set at the upper limit, then having to adjust 18 mrad down would be just about what I'd expect.

The real question is, once you have zeroed the rifle, how many mrad of up adjustment do you have left?

 

[snarkscarbine]

You'll be fine. The Minox has a range of 28 mils on the dial. It has more in the erector. To zero that scope you have to play with it to move the dial range further down in the erector travel, if that makes sense. It was a bit of a head-scratcher the first time I did it, too. You basically have to dial past zero, then slip the turret a few times to move the turret's adjustment range lower in the erector's adjustment range so that your zero ends up on the first rev instead of the second.

 

[Evan03]

What's a normal revolution to be on.
I'm on Rev 5 with 3-15 swfa ss. With my 2506 it gets well passed 100yds

 

[mwinter501]

The Minox ZP5 (assuming a 5-25x56) has a total elevation adjustment of 28 mrad. Have you confirmed you have the full 28 mrad (approx) available of vertical travel? If not, you may have to clear the zero stop.

A 20 MOA base will give you an additional offset of approximately 5 mrad, so in a perfect world, if your zero where to coincide with the optical center, you should be left with a total of 19 (14 + 5) mrad of up elevation. However, since this is an imperfect world you would likely have to use some adjustment in elevation to overcome any misalignment and actually get it to zero. In any case, unless there is something terribly wrong you should have between 15-19 mrad of elevation still left.

My point in all this is, if you started with the elevation set at the upper limit, then having to adjust 18 mrad down would be just about what I'd expect.

The real question is, once you have zeroed the rifle, how many mrad of up adjustment do you have left?

It's 13.7mil left of elevation from zero, just checked.

 

[mwinter501]

FIXED!!

When zeroing, I hadn't realized that I put the elevation cap on the '0' in the second rev until much later. I just took the advice of a few folks here and moved it down to the '0' on the first rev and that seemed to fix the problem. I now have 22mil of adjustment instead of 13.7. I guess it was a problem with the amount of adjustment the knob itself had and not the erector (as Snarkscarbine stated). I didn't originally understand what he was saying until I did it and it now makes sense.

Thanks, everyone, for your help. I truly appreciate it!

 

[digrazir]

Glad we could help.Ray

 

[Kruger21]

Great result!!!

 

[supercorndogs]

What caliber are you shooting, that doesn't get to 1000 in 13.7 mils?

 

[mwinter501]

What caliber are you shooting, that doesn't get to 1000 in 13.7 mils?

308win in a 18" gasser. Technically it should get there, but it's really close and I didn't want to bottom out the director and hurt something. I was dialing to 12 and holding after that.