Scope touching barrel...Problem?


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marksman13
April 10, 2008, 03:02 PM
So, I bought a CZ 527 Varmint Laminated from Xring about two weeks ago. I love the rifle. The trigger is great. It seems capable of being very accurate. However, I am having a hard time finding rings to fit the scope that I want to mount on it. The scope is a Millett 4-16x56. Tried a set of high Warne rings and the scope mounted, but the scope was just slightly touching the barrel. As I understand it, this isn't particularly good for barrel harmonics and could cause some accuracy problems. How big of an issue is this?

I've got a set of Millett extra high rings that should be here tomorrow, but if they don't work, what are my options? Thanks guys.

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Horsemany
April 10, 2008, 03:21 PM
Not good! You don't want anything touching the barrel or the scope. If you can't get rings that will work, I would get a different scope. The scope would likely be stressed if you could get the rings to tighten down even. If you want a scope that sits taller than rings will allow than you will be causing other problems by having a scope up in the air like that. You will have a hard time getting your eye tall enough without an extra cheek piece in most cases. There is generally little to be gained with an objective lens that big. Especially on varmint guns that are mostly used during the day with plenty of light.

Shawnee
April 10, 2008, 03:29 PM
Hi Marksman....

Within reason, you can use a shim between the barrel of the scope and the interior of the bottom ring(s). This can provide a small amount of clearance. You may also be able to use a shim underneath the bases, and with using the two shims achieve sufficient clearance.

Best by far, of course is to find some rings that will accomodate that scope without any "homegrown solutions".

I've seen a .243 that didn't appear to suffer with the objective bell touching lightly against the barrel - but the scope (a new Redfield) only lasted about a year.

"Horsemany's" comments are right on too. Personally, I wouldn't buy a scope large enough to lessen the anchor of my cheek on the stock. That anchor is more important than even having a scope.

Good Luck !!

:cool:

HGUNHNTR
April 10, 2008, 03:38 PM
It has little to do with bbl harmonics, and more to do with not ruining your scope. You don't want a vibrating barrel touching your scope.

Vern Humphrey
April 10, 2008, 03:52 PM
I've seen a .243 that didn't appear to suffer with the objective bell touching lightly against the barrel - but the scope (a new Redfield) only lasted about a year.

That's the problem.

Personally, I never use high magnification scopes -- in 50 years of hunting, I have used a 3X9 set on 9X only once. And the large objective bells and need for high mounts is only one of many reasons.

Shawnee
April 10, 2008, 04:37 PM
Hi Vern...

LOL ! :D

I know what you mean, Vern. I hunted with Redfield Widefield 2x7 scopes for more years than I will admit and they spent 99% of their time set on 5x, or less. When I moved back to Ohio where I can shoot woodchucks I happened upon a used heavy-barreled rifle that already had a 4x10x42 on it. I just checked it and it's set on 6x. :D

:cool:

JWarren
April 10, 2008, 04:51 PM
There is generally little to be gained with an objective lens that big. Especially on varmint guns that are mostly used during the day with plenty of light.


But be a dusk and dawn deer-hunter and you will start paying a LOT of attention to light transmission and objective sizes.


-- John

Vern Humphrey
April 10, 2008, 05:00 PM
But be a dusk and dawn deer-hunter and you will start paying a LOT of attention to light transmission and objective sizes.
The human eye can dilate to about 7mm. A scope (or any other optical instrument) with an exit pupil (the spot coming out the ocular lens at focal point) over that size is simply wasting light.

Exit pupil is calculated by dividing objective lens diameter by power. A 4X scope with a 28mm objective lens will give you a 7mm exit pupil -- all you can use.

A 2 1/2 X 20 will give you an 8mm exit pupil -- more than you can use.

eliphalet
April 10, 2008, 05:15 PM
Go to Brownell's web site and look up your rings, the different heights will be there for you to compare.

. They may still have charts where you can compare rings to scopes, or at least objective bell sizes, to particular guns. Leupold used to, maybe still does but there you Will only find their products. Either way it is a Good idea to do before you buy mounts and rings. Good luck

Vern is correct as the human eye can only gather so much light no matter the objective lens size.

dagger dog
April 10, 2008, 05:18 PM
You may think about a different mount some of them are higher , and give a little mor clearence.

JWarren
April 10, 2008, 05:26 PM
The human eye can dilate to about 7mm. A scope (or any other optical instrument) with an exit pupil (the spot coming out the ocular lens at focal point) over that size is simply wasting light.

Exit pupil is calculated by dividing objective lens diameter by power. A 4X scope with a 28mm objective lens will give you a 7mm exit pupil -- all you can use.

A 2 1/2 X 20 will give you an 8mm exit pupil -- more than you can use.


Right.


But if you use higher power, you would have to use a larger objective to get the same light transmission.

I've hunted most of my life with a 4X fixed optic. I know it CAN be done. But I prefer a 3x9 these days, and practically every hunter I know around here does as well.

My point about light transmission was highlighted last season.

My father was using a Simmons 3x9x50 on a rifle where my mother was using a Nikon 3x9x40. They were hunting in the same area. However, the superior transmission of the Nikon had my mother being able to see 10 minutes longer than my father.

The point being that light transmission at dusk and dawn do matter.

We are getting into a whole new thing regarding objective size. I was never operating from the assumption that one would operate with a 4X optic.


-- John

pgeleven
April 10, 2008, 05:31 PM
i agree that if its touching the barrel you may be stressing the scope, get it off your weapon until the new rings arrive! and once the barrel whips that scope bell enough times you are more than likely going to cause a cancer that will lead to that scopes early demise. personally i wouldnt try for a 56mm objective lens knowing that i would risk losing my cheek-to-stock weld, if light is an issue a 50mm should do just as much as a 56mm, or get a nice Leupold Alumina kit if your scope can 'wear' one.

marksman13
April 10, 2008, 09:46 PM
Thanks for the responses guys. First of all, I do have a cheek pad ordered for the rifle, so cheek weld won't be an issue.

Second, the scope has already been purchased, so I've gotta make it work somehow.

Third, according to the charts I read, the high Warne rings should have worked.

I took the scope off until my new rings come in, but when I tried to mount it, I noticed that I could see daylight between the scope and the barrel. There just wasn't enough clearance for a dollar bill to pass through. At least there appeared to be daylight showing through. The new rings should fix the problem.

I hadn't thought about the scope being ruined. I guess even a .223 would hurt it if it kicked it long enough.

I hope I can get this rifle straightened out soon. I've got to grind a few spacers to put on the butt stock and install that cheek pad. If the new rings work I will be golden. I hope..........

skinewmexico
April 10, 2008, 10:32 PM
You could always put a Farrell or EGW 0 MOA base on it, and probably use medium rings.

RugerOldArmy
April 10, 2008, 10:34 PM
Deleted...missed that you had the Warne High rings already. I don't know if the CZ rings are higher for a 527.

Dr. Tad Hussein Winslow
April 10, 2008, 10:56 PM
My opinion:

1. First, nice rifle - I'm very jealous.
2. On the scope, it depends on just HOW much / how "hard" that it's touching - how much more room does it need to be freed up? If it's more than about 1/64th, then no I wouldn't do it. If it's just snugging up when you tighten down the scope, I don't think you'll hurt the scope or your barrel harmonics. But if it's tightened down to the point of bending your scope, then you'll screw up your scope. So *touching* no big deal, IMO. Being torqued down, no.

22-rimfire
April 10, 2008, 11:11 PM
In my younger days, I only used fixed 4x scopes on my hunting rifles. I prefer 2-7x or 3-9x now for most things now. For varmints, the higher magnification is really a bonus for those long shots. Get the scope off the barrel and you will have a great rig!

marksman13
April 10, 2008, 11:34 PM
Premiumsauces, if you knew how little I paid you would really be jealous. One of the best deals I have ever gotten on a firearm. The scope is just barely touching the barrel when the rings are tight. The new rings are Millett extra highs or something, so they should work out just fine. I'm just ready to get the spacers on the stock and start shooting.

rangerruck
April 10, 2008, 11:52 PM
with cz's, and I've had a bunch, you almost have to get their factory hi rings. They will be high, but they will be absolutely great, and fit into the slots for the mounts just as intended.

countryroads
April 11, 2008, 12:30 AM
I also have a CZ527 Varmint with the heavy barrel. I also bought the Warne high rings and had the same problem with the scope that I had purchased.

I did some research and finally selected Millett rings. They are the highest that I could find and they work great.

The following measurements are the height of the ring from the bottom of the scope tube to the top of the ring base;

Millett .663 inch
Warne .535 inch
Burris .500 inch
Leupold .530 inch
CZ .555 inch

lvcat2004
April 11, 2008, 01:10 AM
Or get this:

http://www.shootingindustry.com/Ftr1206b/LeupoldVX7.jpg

Dr. Tad Hussein Winslow
April 11, 2008, 01:14 AM
ok, marksman, how much? :) (Yes, VX-Ls are sweet!)

marksman13
April 11, 2008, 05:35 PM
You'll all be pleased to know that the Millett high rings fit like a charm. The rifle looks fantastic. I'll post some pitures tonight, but I'll put them in a new thread. Thanks for all the help guys.

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