Scope life on semi auto rifle?

[jlmurphy]

I have a Nikon Buckmark 4x14 on a Mini 14 that I suspect is wandering. I have replaced the factory barrel with a heavy Krieger and it has always shot nice small groups, now they have opened up in a distinct stringing pattern. I can change scopes to test this rifle, but I was wondering what others shooters had experienced with semi auto rifles. I have a box full of scopes with broken cross hairs and tilted reticles from spring piston air rifles, but was hoping others could tell me what to expect from semi autos.

 

[JesseL]

I would check the scope mounts to see if anything has come loose. Unless something has been abused this is a much more likely cause of your problem.

 

[Sharps Shooter]

43 years. I have Weaver 2X8 on my Winchester M100 .308 that's been on there since the year after I got the rifle. And I recieved that rifle as a gift from Mom and Dad 44 years ago. The scope still worked fine this deer season. I don't know if it will work next year though.
I'm just kidding around jl. The fact is I don't think that Mini 14 or yours would be exceptionally hard on scopes. I've heard before that air rifles can tear up scopes that weren't designed for air rifles, but I've never heard anything about semi-automatic rifles being extra hard on scopes.
What's Nikon's warranty like? I believe Nikon should fix or replace your scope if it's wandering. Leupold would if it was one of theirs. I guess you've already checked your mounts and rings for tightness, haven't you?

 

[fineredmist]

The problem with a lot of scopes has to do with improper installation of the mounts and rings. The Rugar rings mount directly to the receive and if the received cuts are not perfect the mounts will be out of alignment and the scope tube will be stressed. The inside of the rings themselves are not perfectly round and flat which also stresses the scope tube which will lead to early failure. Midway and others sell the Wheeler scope alignment kit which contains a pair of alingment bars and a laping bar along with laping compound. This will enable you to check the alignment of the rings as well as correcting misalignment and smoothing the ring interiors. It can be a pain but it works. I have 3 Rugar 77 VTs and used this procedure on them and it does make a difference.

 

[Outlaws]

Verticle stringing is usually a problem with pressure on the barrel. YOu say you recently changed it? Did you re-tighten the barrel band too tight? Does the barrel sit as nicely in the stock as the previous one? When you hold the forearm or rest it on a bench, it may be pusing on the barrel just enough to string the grouping.

 

[GRIZ22]

I bought a cheap scope that attaches to the carrying handle of an AR about 6 years ago. I used in on my M16 at work as a LEO and later my M4. It's a copy of the Colt scope. It must have been through 4-5000 firings over the years I used it maybe 30% of that full auto firing. It also has been subjected to some banging around in the trunk etc. It's never lost zero or let any moisture in. The reticles are getting a little fuzzy but I still use it.