How Do You Accurately Shoot with a C-More?

[10ring]

I'm in the process of moving from a Limited gun to an open gun and noticed I just can't seem to shoot the C-More sighted open gun as accurately as the Limited gun. I was telling one of the better shooters at this past weekend match what I was experiencing and he said that the C-More sight has parallax error. I did a search around here for parallax problems but only came up with 3 hits.

My question is - how do you guys shoot accurate groups when using a C-More sight?

[shred]

There's several things you need to do--

1- keep the distance constant-- the distance between the dot and the bore line is large. The closer to the muzzle you get, the lower your shots will go

2- keep the dot in the center of the lens. Clamp the gun in a vice. Parallax is the difference between what the dot points at when it's on the edge of the glass versus in the middle. Check it out off a benchrest.

3- use the very top of the dot to sight with.

[Guest Larry Cazes]

I am also making the transition from limited to open and find just the opposite is true for me. I have both C-more sighted and Tasco tube sighted open guns and I find that I can shoot MUCH more accurately with these than with my iron sighted Limited gun with much less effort. Another big advantage of the red dot sights is that I can now for the first time shoot with both eyes open, somehing I have never been able to do with iron sights. I thought that the C-more was supposed to have zero parallax error? How high is your scope mounted off the slide? Allchin mount?

[TMC]

I put the bright glowing red thingy on what I want to destroy and press the trigger.

[diehli]

I put the bright glowing red thingy on what I want to destroy and press the trigger.

What he said.

[Thomas Moore]

put an eotech on there and you'll never have to worry about parallax.

a pro once told me if you zero the cmore on a 65 degree day and store it in the trunk of a car and let in heat up to 120 degress the zero will be off.

[10ring]

Okay, maybe I'm being too picky. But I'd like to know where my shots are going. The kind of difference I'm dealing with is being able to shoot a 3" group with the Limited gun and a 5" group with the open gun, off-hand at 25 yds. The C-More is mounted on a allchin mount. I'll have to check out the eotech.

[BSeevers]

What size dot? I also find target selection and where you focus on the dot important

[Ron Ankeny]

I find no difference in group size between my Cmore and irons when shooting groups at 25 yards. Like the guys said, put the red thingy in the middle of the lens, then put it on the target and let it rip.

[Loves2Shoot]

I find no difference in group size between my Cmore and irons when shooting groups at 25 yards. Like the guys said, put the red thingy in the middle of the lens, then put it on the target and let it rip.

ditto

[Ken Kwiat]

10ring,

It sounds like there might be something else going on vs. just the dot compared to iron site issue. You say off-hand at 25 yds. What kind of groups are you getting when you shoot the Open gun off sand bags or a rest? At 25 yds. my guns shoot under a 2" group (from a bag/rest though).

I have C-mores on four guns (two with Allchin mounts) and there is a parallax issue to be sure. But, if you're holding to the same point of aim when you're shooting your groups, the parallax would affect all shots from the same distance the same, i.e., your group might be slightly lower/higher than your point of aim in most cases. If you're sighted in for 25+ yds, the parallax is simply that you need to aim slightly high when close in like under 10 yds. for precision shots. For example, if I'm taking a head shot from 5 yds. I have just learned to compensate by aiming at the top perf. of the head. The other caution with the parallax is to be careful when shooting over the top of a wall (or worse, a no-shoot) -- in these cases also aim a bit higher than normal. 30 mins. of experimentation is usually all it takes to get a good feel for point of impact at the different distances.

But, like Shred and BSeevers suggest, an important part of getting the consistency that you're looking for may be related to dot size. I tend toward one end of the spectrum as I prefer a 4 MOA dot. It just gives me a little extra confidence on partials that I like (and my eye doesn't have a problem picking it up). If you're using a 8 MOA dot from 25 yds, I'd do as Shred suggests and use the top of the dot as your aiming reference.

Hope it helps.

Ken

[Yardbird]

10ring,

From your original question it sounds like the open gun and limited gun are two different guns... if that's the case then I don't see how you can directly compare their groups. You need you shoot the open gun with cmore and with iron sights for group size comparison. The open gun may not be as accurate as the limited gun.

[TMC]

If you're holding the same point of aim and your getting big groups you may have a different problem. My c-more sighted guns do not exactly put a hole where the dot is at different distances due the height of the scope over the bore which is covered in the postes above but it only varies about 3 inches from point blank to 35 yards and all in elevation. That said if I hold in the same place on the target at just about any distance I get excellent groups. Maybe you just need more trigger time to get fimilar with the gun.

[blackdragon]

10RING,

I tend to agree with TMC, If your set up is A-OK. Then maybe more trigger time is in order. I have shot a C-More for a number of years. It can be a real transition from irons to optics at first, then you just get used to it.

Ivan

SCS Vegas

[eric nielsen]

Yes, the C-More has some of the worst parallax of any red dot sight. And it doesn't matter to what you're doing - group shooting. At the same distance, it's the same point of impact, every time. The Allchin is a great mount, BTW.

I think it's possible that you are picking off your shots with the C-More, in other words, putting your attention on the dot movement, and only letting a shot go off when you perceive the movement is minimal. This will hurt your group size, relative to shooting iron sites, where you may be only paying attention to sight alignment and trigger press. Refer to Brian's main website, the section on "Fundamentals", and try out his suggestions for group shooting.

For me, the best groups with a dot come when shooting at miniature white paper plates [dessert plates] or shooting at a plain piece of cardboard with one horizontal stripe and one vertical stripe of tape. The cross is the aiming point.

I see better at 15 yards [indoor range] than at 25 - the groups are even smaller than the difference in distance would indicate. I also turn down the dot brightness for group shooting - lets me see the aiming point even better.

Good luck.

[uscbigdawg]

For zero parallex and without parking a truck on your gun (i.e. the EOTech) an Aimpoint works nicely. Plus, it seems to work okay for that French kid and TGO.

I shoot a C-more and have had zero problems with it both on aftermarket mounts as well as with the standard C-More plastic legs.

If the scope is mounted correctly (i.e. screws tight, etc.) and it's functioning properly, there should be no problem and you want to investigate other areas of potential mechanical problems (barrel, comp, etc.). However, with a 2" increase at 25 yards, my guess is that you're dot is probably too big.

Go with a 6 MOA or even better a 4 MOA dot and check the results. If you're using say an 8 MOA dot, at 25 yards, that bad boy is 2" in diameter to begin with (someone please verify the math, 'cause I'm tired).

Again, try a smaller dot and see what happens before tearing into the gun.

Good luck!

Rich

[TMC]

Another though, what kind of condition is your gun in? If its not new is the slide, frame and barrel lock-up tight? With the sight mounted to the frame slide to frame fit and barrel lock-up become critical to accuracy. If its an older gun check the comp plates for marks from bullet strikes, this will make you blaster shoot like a shotgun if the bullets are hitting the plates.

[Alan Meek]

How do I shopot accurately with my C-More?

With my eyes closed of course.

Just kidding,

I usually shoot the first round then use it for the aiming point for the rest. Knowing all rounds will not impact the same spot as the first round at various distances but it gives me a consistent aiming point. Or i put a paster on the center A and let her rip

Alan

[Kingman]

whats group shooting.

I just kinda point aim and prey to the ipsc god of mercy.

[10ring]

Yeah, maybe I just need more trigger time. The 3" vs 5" groups I mentioned are largely due to my abilities. I believe the guns are capable of much better groups than that. It's very possible that I'm trying too hard with the dot sight since I can see the target and dot in the same focal plane versus not seeing the sights and target plainly when shooting iron sights.

By some of the comments here it sounds like many of you are defining parallax as the difference in POI vs POA at varying distance due to the verticle difference between the bore line and the sight. I'm referring to parallax as the difference in aiming point dependent on where you're looking through the optical sight. It has something to do with the plane in which the optical pointing reference is versus the plane in which the target is. To describe this further, if you were to set the optically sighted gun in a stable mount, or stabilized by sandbags then point the sight at some aiming point down range. Now without touching the gun or sight, move your head up/down, then to the left/right so you are looking through the sight at different angles. If the dot or crosshair moves off of the aiming point you established then the optical sight has parallax.

Thanks for the tips. I try some more experiments this weekend.

[Ross Carter]

I have noticed the effect that I think caspian28r is refering to. Because the dot takes away the aiming error of aligning the front and rear sights with each other, the dot will appear to move around on target more than iron sights. That makes it easy to play " gotcha ", that is to try and make the gun to go off the instant the dot is closest to where you want it. That results in a less than perfect trigger release. It's a different skill set and even though we rarely shoot precision shots in USPSA anymore it's worth learning.

[Ken Kwiat]

10ring,

You're right that I believe most of us are using "parallax" too broadly. In my experience with the Cmore it's just a POA vs. POI at varying distances due to the height above the bore. I have never experienced the true parallax as defined with the Cmore. Without obsessing over the physics of it too much, I doubt that the design would lead to much parallax given the distance between the dot module (diode) and the surface that it is being projected on.

But, I prefer to shoot vs. analyze these things...heuristically speaking .

DVC.

[Guest Larry Cazes]

Ken Kwiat said:

You're right that I believe most of us are using "parallax" too broadly

Yup. As I said before, the C-more design should exhibit almost ZERO parallax and I believe it is advertised as such. This means that the dot should not have to be centered in the glass.

[shred]

Theory is that little town where everything works.

Try it someday off sandbags... set the gun pointing at something 15+ yards away. Don't touch it. See where on the target the dot lands when it's in the center of the glass, then see where on the target the dot is when it's on the edge of the lens.

[10ring]

I made it out to the range this weekend to study this perceived parallax thing some more. I set up enough sandbags to cradle the open gun in a steady position. I placed a 9" paper plate with a ~3" diameter circle drawn on it at 50 yds. The dot size on the C-More in question is a 4moa module so I was able to place the dot inside the drawn circle. What I saw:

1. When positioning my eye so the dot was near the bottom of the display, I could not see any difference in point of aim, POA.

2. When positioning my eye so the dot was near the top of the display, I saw about 1" of movement upwards in POA.

3. When positioning my eye so the dot was near the left edge of the display, the POA moved about 2" to the right.

4. When positioning my eye so the dot was near the right edge of the display, the POA moved about 2" to the left.

So, the up / down direction doesn't have too much error, but the left to right direction seems quite large.