Can flip up scope caps cause grouping issues?

[ajanssen]

This may be a dumb question, but has anyone ever experienced accuracy issues while using flip-up scope caps? I have Butler creek caps on my Tikka 7mm-08. I've had some issues finding a load the gun really likes. On Friday I gave it a thorough cleaning and headed to the range with some Federal bonded tip rounds I just picked up. I fired a couple fouling rounds, then got serious hoping for decent groups, but instead I got 1.5" groups with no real consistency. After about a dozen frustrating rounds my front lens cap fell off. No bid deal, tossed it aside. Magically my next 3 shots were 1/2 MOA. Hmm. Shot 3 more and they were just about as good. What the heck is going on here? I was running low on ammo so I didn't have a chance to put the cap back on and take more shots.

Any chance that a flip-up cap could somehow cause accuracy issues? Doesn't seem possible, but the irony of the tightened groups is hard to ignore. The only other thing I can think of is the clean barrel took about a dozen shots to settle down, but the change was so immediate that doesn't seem likely either. Not to mention I've tried several factory rounds and never found one to shoot what I thought the rifle should be capable of, until the cap fell off. Anyone ever experienced this?

As I'm typing this I started wondering if possibly the front cap could be touching the barrel. I think there's plenty of clearance so it shouldn't be touching, but I guess I need to check that.

 

[Jeremyc_1999]

The only way that I could see a flip up scope cap affecting your accuracy is if it was touching the barrel.

What model tikka do you have? I had a tikka t3 lite and it was accurate as long as I waited between shots and let the barrel cool down. They are lightweight rifles and have pencil thin barrels (typically). I found if I shot and waited inbetween each shot, then I could get a good group.

 

[ajanssen]

The only way that I could see a flip up scope cap affecting your accuracy is if it was touching the barrel.

What model tikka do you have? I had a tikka t3 lite and it was accurate as long as I waited between shots and let the barrel cool down. They are lightweight rifles and have pencil thin barrels (typically). I found if I shot and waited inbetween each shot, then I could get a good group.

It's a t3X Lite stainless. That's what I'm thinking too. Hopefully that's the case, because when it cleaned up I had 3 shots touching. Much better than spray and pray I've been getting.

 

[Jeremyc_1999]

It's a t3X Lite stainless. That's what I'm thinking too. Hopefully that's the case, because when it cleaned up I had 3 shots touching. Much better than spray and pray I've been getting.

I would say that your barrel is heating up and that is affecting your groups.

 

[pabearhunter]

I will bet if you put the cap back on it will shoot just like it did with it off. If you just cleaned the barrel some times it takes a couple shots to settle in. Just my opinion .

 

[PsRpOiGrRiAtM]

Could be a fluke that the scope cap fell off just as your gun was really getting fouled to the point of shooting a consistent group. The only way to confirm is to spend more money on ammo, unfortunately, but a $50-$100 is a pretty minor investment in the long run for finding a load that your gun likes.

 

[Deleted member 16014]

All I know is I'm gonna take the caps off my scope...kidding. My Tikka's have never been real fouling sensitive in any regard, whether pretty clean or 100+ rounds in. Good luck in your solution search.

 

[Millsworks]

No way a little flip up scope cap effects accuracy.
Even if it was wedged in between the scope and barrel. I have a friend who has his crammed in there so tight he can't get it back off.
His rifle shoots fantastic, none the less.

 

[ntodwild]

Cant see a flip up scope cap having any effect on accuracy.

 

[SticksMcKinley]

I would say that your barrel is heating up and that is affecting your groups.

I had a T3x in 7mm-08 that I couldn't get to group to my satisfaction and agree that it seemed to heat up very quickly and start throwing rounds. Adding a silencer made this an almost comedic exercise. I have an older T3 Lite in .308 and it doesn't exhibit the same problem at all.

 

[ImBillT]

It might if it’s one of the see through ones and you were looking through it. Lots of guns need 5-20 shots after a good cleaning before they settle in. That’s most likely what it was. I give a good scrub at the beginning of the season, foul it, sight-in, and never do more than a wet patch followed by a couple dry patches until the season is over.

 

[nhn2a]

As others said I could only see it having an affect if you have very small clearance and the scope cover is actually making contact with the barrel. I have the Tikka T3 Lite in 30-06. It shot about 1 MOA when I first bought it using higher end factory ammo. In an attempt to make it more accurate, I free floated it, pillar and glass bedded it. Now it's easily 1/4 MOA gun still using factory ammo. I could probably make it better by reloading but with these groupings I'm very satisfied.

 

[antelopedundee]

As others said I could only see it having an affect if you have very small clearance and the scope cover is actually making contact with the barrel. I have the Tikka T3 Lite in 30-06. It shot about 1 MOA when I first bought it using higher end factory ammo. In an attempt to make it more accurate, I free floated it, pillar and glass bedded it. Now it's easily 1/4 MOA gun still using factory ammo. I could probably make it better by reloading but with these groupings I'm very satisfied.

One could always put it on with the little flip open tab rotated 90 degrees. I use the BCs and the rear one has to be turned enough so that you don't contact the bolt handle on a left handed rifle.

 

[tzone]

Only if you keep em closed.

 

[Brian in Montana]

I've never heard of flip ups causing inaccuracy, but there are so many different things happening the microsecond after you squeeze the trigger, who can say for sure?

I really sort of doubt that the cover "touching" the barrel would cause a difference of a full 1 MOA, unless it was kinda jammed in there between the scope and barrel. But considering the results you got, it could've been. If I were you I'd test it - all else equal, does the rifle group better with or without. Problems like this can be frustrating, but they're also interesting.