Rifle Scopes Question on elev spring tension

[foxC]

I have read here that keeping the elevation spring under tension tends to cause problems with scopes using canted bases.

I am using a Badger 20 MOA base and Viper Vortex PST 6-24 FFP scope. Tonight I set the zero stops and noticed I have about one full turn down dialed in. Is this too much tension for short term storage.

Which direction would I need to go to relieve spring tension, and how many full revolutions? I am thinking "Up". I have about three revolutions "up" available to me before I feel resistance.

TIA

 

[TallShot]

I know which thread you refer to.

I would think that going the opposite direction of whichever elevation you have used the most of. As in go up a couple rev's if you're near the bottom of your elevation markings, vice versa.

 

[oneshot.onehit]

The subject tends to surface when folks run 40 moa rails some more some less for getting maximum ranging use out of their scopes and then notice that they are to the point of having the turret adjusted right up to the end of travel within a mil or so for their zero without even having the zero stop shims in place – an example of your scope (shims). It was recommended that when not using the rifle that you would give the turret a couple turns to allow the spring to be in a more relaxed tension versus being stored with the spring completely compressed.

The only reason for the recommendation was to take some pressure off of the spring and have it in a more normal compression as you would normally have it as if using no cant or a 20 moa cant. This would in turn eliminate any chance of the spring loosing some of its strength in time.

When we were running 40 moa rails on some of the rifles all that became a habit was giving the turret a good spin when packing up the rifle.

It’s not an issue as to the quality of the product or all the technical flack that surfaces with the physics of the metal. It’s just is good common sense when running that much cant and having the spring compressed tight when shooting at a 100 to 300 and then packing up the equipment to go ahead and back it off a little to relax the spring some and it doesn’t matter what brand your using . As stated just a little common sense and recommended as well by Vortex

One other thing to watch for the folks considering the 40 moa rails is that when a shooter does run close to having the vertical turret bottomed out, that if your windage when zeroed is not fairly centered within a degree that when you sense the turret bottoming out, you may instead wedging on the radius of the scope housing thus having a side push to be careful with

Running a lot of cant has its purpose but for the most part a 20 moa rails and a good scope will cover the needs of most shooters and then your turret position is not a issue in storage after shooting on a med or short course.


oneshot.onehit

 

[foxC]

Thanx for that explanation. I should be ok with the base I am using.

Not many places here on long island to shoot one thousand yards, that I know of anyways. Three hundred yds is prolly the furthest ill be reaching. Looks like I am okay then.

 

[E. Bryant]

Metallic springs will not take a "set" if left compressed for any period of time, at least not at anything resembling typical storage temperatures (high-carbon "music wire" steel is good to about 250F, and 304 stainless should be good to somewhere north of 500F).

Springs may take a "set" the first time that they are compressed to a particular height, and they may also take a "set" with repeated excursions to a given height; if the latter happens, then there will likely soon be a problem with spring breakage. Dealing with the former is typically a simple matter of compressing the spring once to a position beyond which it will experience in normal operation, which is typically done as part of the manufacturing process.

If erector spring breakage or deformation is going to occur as a result of excursions to the scope's travel limit, then it will happen regardless of the time that the scope is stored at the limits of travel, and it will likely become worse with additional cycling of the erector position. And if a scope were designed in such a way as to allow this to happen, I'd consider it to be an inferior product which has no place on a serious firearm.

Before anyone asks, the same holds true of firearm magazine springs, as well as any other severe-use mechanical product. By the time an automobile hits 250,000 miles (a pretty typical lifespan nowadays), the valve springs have probably experienced somewhere in the neighborhood of a half-billion cycles, and have been stored at or near full-compression for a cumulative time of several years (often at high temperature). If a couple-dollar spring - manufactured by the lowest bidder - can survive this punishment, so can a properly-designed rifle scope erector spring.

 

[dcjs]

...

Very well put. This is one of those cases where physics trumps "common sense". Springs do not "tire" from being subjected to a constant force like a muscle would, they tire from compression/expansion cycles. So by "relieving" the erector spring after shooting, you're actually doing it a disservice, if anything. In practice, a properly designed erector spring should not reach any critical operating conditions by moving the erector (individual defects aside).

 

[Trigger Monkey]

Since I beleive I'm the author of the article that's being referenced allow me to comment on where I was coming from with that statement. When I was working in CS for an optics company it was not that uncommon for a customer to call in with a complaint about their Leupold not adjusting properly. IIRC these were mostly guys with 1000 yard benchrest guns that would shoot a few matches a year and then dial their scopes back to their 100 yard zero and store them for a few months. After years of being stored under compression, used, and dialed back to zero sometimes the springs would not provide adequate tension against the erector resulting in guys not being able to get consistent adjustments or not enough to reach longer ranges. Nearly every time we'd get the scope in and take it apart the springs would be shot and require replacing, which typically solved any adjustment issues. I've also seen poor quality springs that could be compressed with my thumb and not spring fully back but again this was due to poor tempering of the spring.

All of that being said I've left my NF scopes compressed for months and have not seen any ill effects so YMMV depending on the scope and quality of the components. I'd like to also add that I feel the components that are going into riflescopes today are very good and much better than what may have been used in the past. This coupled with manufacturers keeping tighter quality control standards could mean that issues such as the above referenced one could be less and less common.