Problems sighting in C-More

[speculatorking]

I'm having problems with my Cmore. First let me say all of my screws seem to be tight. I was verifying my zero today shooting off sandbags. At between 7 to 15 yards I get a very tight group or tight cluster dead center on my X-ring. Now when I go out to 25 yards all my shots seem to be off to the right on the outside edge of a 4" X-ring. None of my shots are in the center anymore. If I adjust the windage screw to move my group over to the left, I can then get my shots back in the center out at 25 yards. However, now up close (7 to 15 yards) my shots are now hitting slightly off to the left. Mind you, not much but not where I want them to be, dead center. I called Cmore the other day and they told me not to tighten the locking screws much. Just turn them til you feel contact. If you crank them too much you will effect your zero. I know I'm not over-tightening the locking screws. I'm wondering if there is something wrong with my dot module or something else. Any suggestions? The gun is a Springfield 1911. Very tight slide to frame fit. AET barrel 9mm. Allchin mount.

Edited November 4, 2010 by speculatorking

[dansy]

Personally I zero my C-More at 25 meters.....the fact that you hit low at 25 yards...it pretty normal...depending on how high the scope is mounted on your gun....if it's one of the 90 degrees I would say pretty excessive...the strange thing is that you are shooting left especially if you are a right hand shooter...

Also make sure your grip screw are tight if it's on a S_I type gun? don't ask how I know....

Scope mount tight.?

It could be how precise your gun is (or not in this case)

You need to describe your gun a little how old / type ect then we can all guess why it shoot all over the place, but the fact that you group in both distances....I would be tempted to say your gun is that accurate, nothing more nothing less.

[Hi-Power Jack]

How many shots are you firing at each distance/sight setting?

Sounds like you have extremely repeatable results, but may

not have enugh shots fired to draw conclusion. Moving 2" to

the right at 25 yards is not a huge change. How large is

your 10-shot group at 25 yards?

There are 9 screws to keep tight: the two top grip screws,

the two on top of the sight and the five holding the mount

to the gun. Make sure they're all tight.

After you make an adjustment to the sight, fire more than

one five shot group - make sure the adjustment has settled in.

And try some 10 - 15 shot groups at each range.

[jid2]

It's not the dot module. All the module does is create the light source, if it's on it's working as designed - everything else is done with lens positioning.

[speculatorking]

Ok it's not the dot module. Thanks. I shoot 2 or 3 shots at each distance from say 7 to 15 yards. They all hit pretty much dead center. I really am pleased with the group. Then out at 25 yards all shots are out on the edge barely in the X-ring. At 25 yards I shoot 5 or 6 shots. I did check all screws and they all seem tight. (mount screws/sight screws and grip). I have shot a ten-shot group with this gun at 25 yards before that was about an inch.

Edited November 4, 2010 by speculatorking

[Hi-Power Jack]

Ok it's not the dot module. Thanks. I shoot 2 or 3 shots at each distance from say 7 to 15 yards. They all hit pretty much dead center. I really am pleased with the group. Then out at 25 yards all shots are out on the edge barely in the X-ring. At 25 yards I shoot 5 or 6 shots. I did check all screws and they all seem tight. (mount screws/sight screws and grip). I have shot a ten-shot group with this gun at 25 yards before that was about an inch.

You have me really confused. If I set my c-more for 25 yards, at 7 yards

the bullets land two inches low. Say, is your C-More mounted sideways?

If sight is sideways, then the 7 yd shot would move to the left, since

that would be down if the sight were upright?? Did I get that right?

Can't imagine why bullets would move 2" to the right. Unless you have

the sight mounted sideways, or you're firing too few shots to form a

meaningful group size.

Going to follow this thread - dying to find out the answer.

Jack

[Singlestack]

I split this out from the other thread.

[Singlestack]

Have you tried zeroing the scope at 25 yards?

[jid2]

You have me really confused. If I set my c-more for 25 yards, at 7 yards

the bullets land two inches low. Say, is your C-More mounted sideways?

If sight is sideways, then the 7 yd shot would move to the left, since

that would be down if the sight were upright?? Did I get that right?

Can't imagine why bullets would move 2" to the right. Unless you have

the sight mounted sideways, or you're firing too few shots to form a

meaningful group size.

Going to follow this thread - dying to find out the answer.

Jack

A normally mounted C-more sighted in at say 25 yards will always shoot low as the distance is reduced, and will max out at the distance the dot rests above the center-line of the bore. This is caused by the dot being above the bore center-line and not the mechanics of the sight. So even a sideways mounted C-more will have this issue of elevation change for point of impact vs point of aim, but it will be less drastic as the dot is closer to the bore center-line on a sideways mount. there is a really good thread about this somewhere, I found it when I was screwing with my sight at first - it contains a spread sheet that graphs the point of impact vs point of aim and different sight-in distances and MOA sizes.

The key to keeping things tight with left to right adjustment is to sight in at a longer distance (like 20-25 yards) as this will give better feedback to the actual precision of the sight-in. Then you can adjust the elevation to what ever you think is best for your shooting style. But be sure to check left-to-right at distance again after you make elevation changes as they get mixed together on a C-more due to the living plastic hinge.

All that said for the OP, your issues seems a little bizarre. Maybe there was a cross-wind.

Edited November 4, 2010 by jid2

[SLM]

Your mount/sight isn't perfectly in line with the bore. Sight in at 15 dead on, move to 25 and the group is off to the right. Center group at 25 and now it's left at 15. The site moved right where you adjusted it. If I were you I'd center it up at 25 and roll with it. If it really botheres you, you're going to have to get the site perfectly aligned with the barrel.

[Jaxshooter]

Something else you need to consider is the size of the dot. At 25 yards an 8 min dot covers 2". At 12.5 yards it only covers 1". If you zero the gun at 12.5 yards, the point of impact can be off that additional inch at 25 yards just from the area the dot covers. Shoot out at 50 yards and you have a 4" area for the point of impact to vary from the 12.5 yard zero. In all these cases the gun is shooting to the point of impact it was zeroed to. C-Mores"s are not precision instruments.

[speculatorking]

Thanks for all the responses. One thing I should have added is when I shoot up close at say 7 yards, I hold at the top of the 4" X-Ring to hit dead center. Out at 15 to 20 yards I just aim

dead center and that is where it hits. The mount is a normal Allchin mount and I have a 6 MOA dot. When I start out and zero at 25 yards, then the shots up closer are off to the left of center. Still the gun is plenty accurate for shooting steel.

Edited November 5, 2010 by speculatorking

[jid2]

Found the thread, this is money for understanding the factors related to sight-in distance.

http://www.brianenos.com/forums/index.php?showtopic=4236&st=50&p=987070&hl=cmore+%20zero&fromsearch=1entry987070

[G-ManBart]

The mount isn't parallel to the bore. That's why you only have one distance where the impact is centered and at shorter ranges it's off to one side, and longer ranges off to the other side. R,

[Supermoto]

I ran into the same issue not to long ago. I sight in at 50 feet. I was shooting at 45 yards with a nice tight groups but they were off the the right. changed the windage, but was off to the left in close. I think either my mount or the cmore took a hit and may have a slight bend. (I had my slide racker break off in my hand the practice before, so something happened) I haven't had a change to swap out the c-more or the mount to determine which is the cause

[Pat Miles]

Speculatorking,

In two of your posts you say that your screws "seem to be tight". If you want to be able to troubleshoot this problem you need to make sure the screws ARE tight. You cannot eliminate possibilities unless you determine that the particular possibility is doing or not doing what it is supposed to do or not do. Without verification you may be chasing your tail for a while.

Pat