Christensen Arms Issue or Scope Issue

[The_Whitetail_Kid]

I know this isn’t my first post on here talking about zeiss scope not tracking or Christensen arms moving POI but let me get some opinions here. I have been shooting my Christensen Arms Ridgeline 7mm rem mag with 160 accubonds topped with a Zeiss v4 6-24x50. My mounting system is a nightforce rail with nightforce rings, torqued to spec. This gun has been shooting extremely well for me the past couple months. And all the sudden, I started missing the target at 400 yards and all my shots appears to be high. So I went back to 200 yards, where it was originally zeroed for and found it to be about 3 inches high. I backed it down and it was dead on. But I shouldn’t have had to do that. Gun was cleaned prior to verifying zero and after the misses at 400 yards. Grouping exceptionally well and where it needed to be left and right, just high. To me, it sounded like a tracking issue and after a round of dialing it didn’t return to zero. I removed the scope and found everything to still be tight. This is like the second or third issue I’ve had with zeiss all related to tracking. I don’t see how such a known scope could be failing more than once. I don’t see how it could be a mounting issue when everything is to spec, and it’s only happened with zeiss scopes. It has all been, on the same rifle. Got me to thinking, could it be the rifle? Should I switch brands of scope or check something on the gun? What could this be? I know a lot of people aren’t fond of Christensen rifles so figured it could definitely be a possibility.

 

[jjrgr21]

Had to have my V4 replaced for exactly that

 

[HvyBeams]

Are you checking to make sure you adjust the parallax out of the scope, even when you sighted it in. Might be an issue, or not. I had another brand scope that the parallax adjustment needed to be reworked by the manufacturer.

 

[MattB]

Action screws still tight?

 

[Bowhuntone]

Step one verify all screws on base and rings are tight . recommend removing cleaning both screws and screw holes in action then loctite and re- torque. shoot and see if it group consistent , if it still doesn't, try another scope, best if known to hold zero.
The only way is to trouble shoot thru each part to verify if it is the issue or not. I would go mounting ( base and rings - check all screws for torque, change scope, then gun. also could swap scope on to different gun to see if it dials or not.

I have a ridgeline in 300 win mag and started shooting high and was a loose screw (front one) in base. After cleaning and re torque it has been holding zero for 2 years now

 

[Plainsman79]

If you cleaned the barrel before shooting, did you shoot a couple “foul rounds” before going out to 400 or did you shoot the clean barrel at 400? I know my Ridgeline shoots a bit different right after I clean it. Just a thought..

 

[Theringworm]

My opinion, I would never purchase a Zeiss (or Swaro for that matter) scope if I intended on dialing a lot with it. Sure, glass is amazing, but they aren’t really built with the internals to be used for frequent dialing.

Second, if you haven’t read all of the horror stories of owning a Christensen rifle just do a quick search or look and see how many are for sale in the classifieds. Their quality control has to be some of the worse in the business. Year after year it’s the same repeated problems.

As mentioned above, start with one thing and problem solve/rule it out, then move to the next. I feel it could very well be either the scope or rifle given my prior comments. If you have a different scope that’s reliable you could switch out the Zeiss for it and quickly rule in/out the rifle or the Zeiss scope that you removed. Just double check the NF rings and rail to insure they are torqued to spec. Doubtful it’s the rail or rings. It always nice to double triple check. I might start there first.

 

[Sandstrom]

Clean, degrease, loctite, torque all screws including base and action. Remount scope and try again.
Out of curiosity, you mentioned that everything was to spec, what torque values are you using for each screw?
Ryan

 

[ResearchinStuff]

Youre cleaning the barrel too much. And what the v4 is known for is to be mechanically unreliable.

 

[Skerhunter]

I had to trouble shoot one like this that I bought a few years ago. I bought it used with a vx3 on it and feel bad for the original owner. It was one of their custom guns. The torque specs for the stock was extremely picky. If they weren’t perfect it would shot terribly. Also his scope was in question. I swapped stocks and scope, now it doesn’t lose zero and shoots fantastic.

 

[turbobrick]

The fact that it’s a straight vertical error and you can correct it with dialing really leans me toward a scope issue. Make sure you’re putting a few fowling shots through the gun after cleaning to correct for any error in POI from that.

 

[The_Whitetail_Kid]

I will add that after it was cleaned, several foulers were shot before any assumptions were made

 

[grog24]

Action screws still tight?

This.
I have a buddy who was chasing his tail thinking his Nightforce took a dump.. It was semi-loose action screws.

Check action screws before doing the whole scope thing.. I do agree with @Sandstrom advice above. Remember when machining things, oil is used. Which is the opposite of what you want when mounting a scope. Degrease all bolts (I use Acetone), all threaded holes (acetone on Q-tip, etc.), blue loctite and torque everything correctly. Make sure to degrease the inside of the rings and outside of the scope body... This assumes acetone won't mess up your finishes (YMMV)

 

[The_Whitetail_Kid]

Yes, action screws still tight.

 

[Weldor]

Following

 

[Sandstrom]

Yes, action screws still tight.

What in-lbs are all the action screws and all screws related to the scope set at? Also, if I had to put money on what the problem is, it would be on the scope.
Ryan

 

[Fartrell Cluggins]

Generally a problem with the stock would give you more sporadic results. If you came back in to 200 yards and shot a tight group that was centered 3 inches high, I'd suspect the scope.

 

[The_Whitetail_Kid]

Generally a problem with the stock would give you more sporadic results. If you came back in to 200 yards and shot a tight group that was centered 3 inches high, I'd suspect the scope.

That’s what I was thinking. I thought If it was something sit in the gun, it would be shooting like a shot gun.

 

[The_Whitetail_Kid]

Went back to the range today with a night force on it, and I think I’ve determined it’s the gun. Was sighting it in for 200, so needed to be about 1.5 inches high at 100. Scope was not messed with during the process, as you can tell the group worked down. The better was never overly hot as I waited some time to let it cool back down in between shots.

 

[Sandstrom]

Looks like a 3 inch group centered about 1.5 inches high.