gng4life Posted April 25, 2013 Share Posted April 25, 2013 So my 9Major Open gun has a problem. I'm pretty sure it's the Cmore but I want to see if anyone has seen this before. For over a year, this pistol has been shooting great, no issues at all. A few weeks ago I was at a big match and I noticed I couldn't hit any steel on the first stage. I saw the dirt in the berm so I just moved the dot and down it went. To make a long story short, I found out my point-of-impact had shifted dramatically. For instance, at 3 yds, it could be dead on. At 5 yds, it moves a few inches in the upper left corner. At 7 yds, it moves a few more inches, high and to the left, and so on. At 15 yards, the group was about 12" left and about 12" high. If I adjust the Cmore at 15, then the groups move the other way. This is a full size Open, Cmore in a Quinn II mount. Just wondering if anyone has seen this and if you think it's the same as me. Also, the mount is rock solid. Thanks for any input... Link to comment Share on other sites More sharing options...
yoshidaex Posted April 25, 2013 Share Posted April 25, 2013 Crack in the body? I had a few instances of shifting POI. One was due to a crack in the body. The other was the set screw for the elevation adjustment backing out. Link to comment Share on other sites More sharing options...
gng4life Posted April 25, 2013 Author Share Posted April 25, 2013 That makes sense. Will be taking the sight off tonight to check it more thoroughly. I checked the screws at the range yesterday and marked them, looks like they are not moving at all. Especially both of them at the same time. Was your shift this dramatic? Thanks for the input! Link to comment Share on other sites More sharing options...
Sarge Posted April 25, 2013 Share Posted April 25, 2013 Maybe change the battery before tearing it apart.' My comp came loose causing my gun to get erratic grouping. Link to comment Share on other sites More sharing options...
GrumpyOne Posted April 25, 2013 Share Posted April 25, 2013 I accidentally shifted mine one time....with a forward assist of the slide...at 15 yards, went from being dead on, to shooting 6" high, and 4" to the right...re-adjusted the Cmore, and back on track... Link to comment Share on other sites More sharing options...
GrumpyOne Posted April 25, 2013 Share Posted April 25, 2013 Maybe change the battery before tearing it apart.' My comp came loose causing my gun to get erratic grouping. Ah, the old "My comp came loose..." excuse....Heard it a thousand times..... And the battery is not a bad idea....but, everytime I change the batt in mine, I have to re-zero it.... Link to comment Share on other sites More sharing options...
gng4life Posted April 25, 2013 Author Share Posted April 25, 2013 Thanks guys, forgot to mention I changed the battery twice and then went back to the old battery but no luck. Also, changed out the module with a spare I carry. Shifted it a little but it was still way off. Link to comment Share on other sites More sharing options...
Mark R Posted April 25, 2013 Share Posted April 25, 2013 I had the lock screw in the windage adjustment on a C-More become loosened during a match. Caused the POI to shoot left about 3-4 inches at 10 yards. Luckily it was a local steel match and the last stage...which I bombed. After re-zero, I now have slippage mark paint on all my C-more set screws. Link to comment Share on other sites More sharing options...
BSeevers Posted April 25, 2013 Share Posted April 25, 2013 They break too. Teammate had same thing happening and now is fine with a new scope Link to comment Share on other sites More sharing options...
lcs Posted April 25, 2013 Share Posted April 25, 2013 Check all screws!!!! Including the ones holding the C-more to the mount. I had a screw come loose and the exact same thing happened. The front of the C-more had moved to the right. (you had to really look hard to see it). Does not take much. Mount moved to right--dot shoots left POI. Link to comment Share on other sites More sharing options...
gng4life Posted April 25, 2013 Author Share Posted April 25, 2013 Ok, will check the screws again but I thought I checked them pretty good so far. Was it this extreme? I mean at 25 yds, my shots are off the metric target if it is dead on at 3 yds. Thanks! Link to comment Share on other sites More sharing options...
Jaxshooter Posted April 25, 2013 Share Posted April 25, 2013 I have 4 C -Mores 3 hold zero perfectly. I rezeroed the other one 4 or 5 times and still had shifts in POI. I read somewhere on this forum that the lock srews tend to strip the threads in the plastic case. I took both lock screws out of the sight and put blue loctite on them and let it dry completely. I put small lock washers on the lock screws and reinstalled them. The loctite made the threads tighter. I re-zeroed the gun at 17 yards and then shot it from 35 yards to check the windage adjustment. I made sure I locked down the screws between every adjustment so the was no shift in zero. Since I did this the C-More has held zero perfectly. Hope this helps. Link to comment Share on other sites More sharing options...
lcs Posted April 25, 2013 Share Posted April 25, 2013 Ok, will check the screws again but I thought I checked them pretty good so far. Was it this extreme? I mean at 25 yds, my shots are off the metric target if it is dead on at 3 yds. Thanks! Indeed it was. Link to comment Share on other sites More sharing options...
gng4life Posted April 25, 2013 Author Share Posted April 25, 2013 Ok, thanks Jax and Ics, I'll do that... Link to comment Share on other sites More sharing options...
AWLAZS Posted April 25, 2013 Share Posted April 25, 2013 It is strange that it hits point of aim at one distance and then groups off to the right at distance Link to comment Share on other sites More sharing options...
gng4life Posted April 26, 2013 Author Share Posted April 26, 2013 So, I had time last night to go over it again and check closely. The two screws holding the Cmore to the mount were very tight, maybe even a little too tight. I checked the windage and elevation screws and they were at the same location (I painted a mark) and the lockdowns were tight also. I loosened them up and moved the elevation and windage around and they seems to work fine. I pulled off the bottom cover and the PCB looks fine. Overall, I can't find a thing wrong with it externally. I plan on purchasing a new Cmore to put on it and test it out. I need another one anyway for a new build coming up so I'll just buy it a little sooner than I had planned. It just sucks about the timing, just finished a big match and have another one next week... Thanks for all the help so far. Link to comment Share on other sites More sharing options...
jrb06 Posted April 26, 2013 Share Posted April 26, 2013 Check for cracked grip and loose grip screws also. Link to comment Share on other sites More sharing options...
lcs Posted April 26, 2013 Share Posted April 26, 2013 So, I had time last night to go over it again and check closely. The two screws holding the Cmore to the mount were very tight, maybe even a little too tight. I checked the windage and elevation screws and they were at the same location (I painted a mark) and the lockdowns were tight also. I loosened them up and moved the elevation and windage around and they seems to work fine. I pulled off the bottom cover and the PCB looks fine. Overall, I can't find a thing wrong with it externally. I plan on purchasing a new Cmore to put on it and test it out. I need another one anyway for a new build coming up so I'll just buy it a little sooner than I had planned. It just sucks about the timing, just finished a big match and have another one next week... Thanks for all the help so far. If you send it to C-more, they will check and they do a fast turn around. Link to comment Share on other sites More sharing options...
ledavatar Posted April 26, 2013 Share Posted April 26, 2013 The POI shift happened to me a few years back. For me, the reason was a new limcat glare shield I installed. I don't know why, but it changed my POI, and weirdly it kept on shifting, so I had to remove it. http://www.shootersconnectionstore.com/Limcat-C-More-Glare-Shield-P422.aspx Link to comment Share on other sites More sharing options...
DrawandDuck Posted April 26, 2013 Share Posted April 26, 2013 (edited) a 3 yd zero will affect your shots at longer range more than you think......is it consistently off or does it jump around....Once I get mine zeroed I too locktite the set screws and also witness mark the C-more body in case it does move I can go re-zero quickly. Edited April 26, 2013 by DrawandDuck Link to comment Share on other sites More sharing options...
gng4life Posted April 27, 2013 Author Share Posted April 27, 2013 It really wasn't a 3 yd zero. I zero all mine around 17-18 yards. When I took it out to check it, it was hitting dead on at 3 yds and the groups would shift. They were groups so it wasn't scattered all over. Ledavatar - you may be onto something. I have a Arredondo glare shield on it so I'll find the original cover and replace it. I'll see if that makes a difference. Thanks for the info... Link to comment Share on other sites More sharing options...
gng4life Posted April 27, 2013 Author Share Posted April 27, 2013 Check for cracked grip and loose grip screws also. Thanks, did that last night when I was checking the screws on the scope, all were really tight. No cracks visible but I didn't take it off the frame. Might do that this weekend. Link to comment Share on other sites More sharing options...
Sarge Posted April 27, 2013 Share Posted April 27, 2013 Guess it's time to call Cmore. Sounds like a bad unit at this point. Link to comment Share on other sites More sharing options...
gng4life Posted April 27, 2013 Author Share Posted April 27, 2013 Going to change the glare shield first and try that tomorrow. If no luck, it's going back on Monday. I sent a few units in the past for failed switches and they usually had it back to me in a week or two. We will see...thanks for all the info! Link to comment Share on other sites More sharing options...
cecil Posted April 28, 2013 Share Posted April 28, 2013 is it necessary/prudent to re-zero a C More scope after a battery change ? Link to comment Share on other sites More sharing options...
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