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Glock 40 10mm issues

    1. Bama rolls
      I almost don't want to post as I have researched this issue all over to find a solution but just never found anything to satisfy me. I have a 10mm model
      40 that I can't point of impact to be where I am aiming. I've tried different types of ammo and different grains of bullets that all hits target mostly left, some lower than others but all left. Some background about myself 50 yr old reloaded very seasoned at shooting/hunting outdoors activity. Owner of several long guns and pistols that hit where I aim. I own another Glock in 40 caliber that shoots like a dream. No issues regarding point of impact. I've never shot reloaded ammo in glock model 40. I have even put it On a rest and it still hits left. I hate pistols that a person has to move sights all the way right to move point of impact to center. This gun groups good but is always 6 inches off at 17 yards. I've put a laser on it and practiced trigger pull so flinch is not an issue. I'm at a loss and believe it's in the gun somewhere. Anyone got any other ideas?
  1. Drift the rear sight.
  2. I could but like I stated I don't like guns that have to have the sights adjusted all the way right to hit the mark in the center. I don't mind moving it a little for small corrections but this would need to be moved as far right as it would go
  3. Bama, have you had anyone else shoot it to see if it happens with them, too? Just trying to eliminate as many factors as possible. Are the groups you are getting 6" to the left at 17yds tight groups?
  4. +1 at having someone else shoot it, preferably an experienced Glock shooter.
  5. Yes the gun groups very well. I have not let anyone else shoot it but I do have that planned soon
  6. i
    the 10mm frame is big to begin with which makes it almost impossible to add something like an aftermarket grip to it. Since it's a full size no need to put an extension on it. My hands are medium size so I don't have any extra room to change grip size. I may have to change my grip pressure. I've already tried more and less trigger finger and it made no difference.
  7. I'd be surprised if somebody can tell you how to do something inside the pistol that causes it to shoot the other direction. If it drifting the rear sight is not acceptable to you, then perhaps you're at an impasse and the only solution is to replace the gun. I'd bet you that drifting the back sight is all Glock would offer to do for you.

    I'm going to check this thread periodically to see if somebody has a simple techinical cure. I'd like to hear it myself. Good Luck!
  8. thanks TGT
  9. Maybe this will help . A guy on the Beretta forum a few weeks back was having the same problem with his new Wilson Combat Beretta . It was shooting way left . He swapped in a barrel from his other Beretta 92 and the gun shot right to point of aim . So the factory put a new barrel in it and it now shoots fine .
    Do you know anyone else that has a G40 that you can swap barrels to see what happens ? Worth a try .
  10. I would probably let someone else shoot it before I spent any money on it. At least then you may have a better whether or not there is an issue with the gun.
  11. This week end my brother and I plan to get together and I'll let him shoot it. He has the exact same gun I have so maybe we can figure it out. Thanks
  12. I installed one of the extra backstraps that came with it. That should tell me if it's a grip issue. That will make me change how I hold it. I don't like the extra grip but hey if you don't change something you should not expect a different result
  13. Could be a grip issue I agree. I have problems switching back and forth between Glocks and 1911's sometimes. The different grip changes my POI.
  14. If he brings his too, it would seem you could each shoot each gun which could be close to a perfect test.
  15. It will be this weekend so I'll let y'all know afterward. Thanks everybody
  16. Honestly, I am baffled. All I can figure is, assuming you are right handed, maybe you are gripping too tight with your support hand and pulling shots to the left. But these situations are damned difficult to diagnose. Glocks aren't known for stellar accuracy, but I've never heard of one consistently throwing left of center shots. I know it's got to be frustrating. Keep us posted!
  17. If you decide to try drifting the rear sight, try about .080" to the right for the rear. That should pull you POI 6" to the right at 17 yds. Also make sure your front sight is secure and straight.

    Good luck.
  18. I will but it may be this weekend. Thanks for you comments
  19. Thanks I'll do that. I appreciate everyone responding with useful helpful suggestions. Means a ton to me
  20. I just got a Glock 40 MOS. I took a pistol rest to the range to adjust the stock sights. It grouped on target just fine. I mounted the Vortex Venom and adjusted it. So if it shoots right, left, high or low, I know it's my faulty grip.
  21. So, you insist the gun shoots left from where it is aimed (you've even used a stand) AND you don't want to adjust the sight. I see three options. 1) Aim right. 2) Return the gun to Glock to have it checked. 3) Sell it.
  22. I d
    I don't mind moving sights but I believe sights should be for fine tuning point of impact not out right fixing poi. In order to correct this pistol so far the rear sight will have to be moved right as far as possible
  23. I have some more testing in mind before I make a big move like getting rid of it. Thanks
  24. BTW, I don't believe I read anywhere in this thread that you tried benching the gun. Did you? I do this preliminary POI try-out with every handgun I have ever bought, or, when testing a new handload POI;

    I simply kneel firmly with both knees on the ground or sit firm at the bench (depending on if you are at a pistol stall or at a rifle bench) and hold the gun firmly with two hands onto the bench or the stall shelf. Take very deliberate and careful aim through your sights (as you have always lined up the sights) and pull the trigger slowly and take a few shots this way. Any Glock, Sig, 1911, or other quality pistol I've ever owned will always put the shots into a tight cluster at 25 feet. If you were to try this and get a tight group exactly where you are aiming, then you will know the gun shoots straight, and it's your style of shooting or grip that is to blame when it shoots left.

    I always try out any new pistols or handloads this way. In the past, I've had other shooters walk by me on the firing line, catch a glimpse of me shooting like that, and sneer or laugh at me with their friends. Evidently, a lot of folks have no clue what I'm doing and never do this basic test of their ammo or their gun's POI.


    how convenient your brother has the same gun! If after the POI test, you find the gun truly does shoot to the left, you might just try swapping out the barrel with your brother and see if what Nick B said (in post #11) changes anything.
  25. Have a gunsmith make you a custom set of sights with the front sight shifted slightly to the left and the rear notch shifted slightly to the right.

    Either that or send the gun back to Glock or sell this gun and buy a different one.
  26. I put the gun in a make shift vise this pm. Same result. I made some pics. Maybe I can get them to post. The 2/3 target is about 50 yards away. As u can see it barely hit target
  27. Well then, I think that settles that. It's NOT you. As you know, it will be real easy to borrow your brothers barrel and drop it in your gun and see if that makes a difference. If you're lucky, a barrel replacement will be the answer. And if you can determine that for sure, and let Glock know it, I'd bet they would swap out the barrel for you. Otherwise, without knowing for sure why it does it, I'd bet they will only drift the sight for you and send the gun back to you.
  28. Ooops....Duplicate of my above post.

    Bama, yes, it will never hurt to ask Glock. But in my experience with so many gun manufacturers, very often they are courteous and tell me on the phone to just send it in to them. (ie; standard procedure) .....and they send it back to me with the same dang problem. I had a terrible experience with Kahr in partuiclular who had me pay shipping Twice! Nothing ever got fixed. Shipping is expensive, especially when overnight shipping is required!!!..... and so too is test ammo.... if nothing ever gets fixed. But yea, I'd call too just to see what they say.
  29. Just curious, did your brother shoot the gun yet?
  30. sorry but I cant get the pics to display. what I did was put the gun in a lead sled and I use a strap to Velcro my long guns in it. I got the strap to go in the trigger housing and strapped it down to the bar underneath the gun supports on the sled. I put 3 hits on the 17-20 yard target it grouped all 3 shots close together. I went ahead and shot one shot at 50 yards and just barely hit the target. Im thinking of contacting glock about it. I guess it will not hurt to ask.
  31. no
    not yet
  32. I did free hand one shot with the thicker backstrap and it did not change it at all. Im about ready to save my ammo and see what Glock says.
  33. Well, there were some Glocks produced that had defective locking blocks. Some shot as much as 12" left and high at 15 yards by the Range Master, who is also an Master Class USPSA shooter. It was a local PD and they replaced the units.
  34. I've worked at a range 17-21 hours/week for just over 2 years now, mostly on the firing line as an RSO. I see this 7:00 stringing pattern all the time with right handed shooters (5:00 with left handed). If the pattern is in a line roughly, it tells me that you are probably establishing a good sight picture but you're changing something in your interface with the gun (grip/trigger) just prior to firing. The fact you also experience this with the 10 and not others makes some sense too because of its recoil. To be honest, I don't know if it's a change in grip pressure, tensing against the shot or trigger application but it is, by far, the most common problem I see.

    Try this, just as a test, I'm not recommending you shoot this way permanently. Instead of using steadily increasing pressure on the trigger, go in stages, 10% increase, 10% increase, 10% increase....bang. The simple act of having to concentrate on small incremental stages in pulling the trigger usually lets the shot happen more by surprise. This keeps you from bracing, changing grip pressure or being overly aggressive with the trigger when you think you've got the best sight picture. If your group improves then at least you are on the right track.
  35. Thanks I give it a try
  36. This target is from a relatively new, young, right handed shooter. The number 4 target is what he had shot first. The next two targets, two then six, were what he shot next trying the same thing I suggested above. Like I said, it's not a recommended way to shoot, just a way to help isolate and diagnose the problem.

  37. Sounds very much like a grip issue to me. I carried G30 & G21 my last ten years as a cop and while I qualified with very high scores, I shot to the left more so than with my 9mm's and .40's. The exception was my G36. I have never had issues along those lines with the 36. I finally took the G21 to Robar and had the grip diameter reduced. End of issue.
    I have average sized hands and am not intimidated by recoil or large guns. I carried a S&W 629 4inch barreled in .44 magnum as a Sheriff's Deputy in the 80's. But I did go to a rubber (Safariland) smaller diameter grips to accomodate my hand size. I always shot and do shoot well with it today.
    Since the full size 10mm and .45ACP are the same sized frame, I suspect that you have the same problem I did. I am also getting my G30 grip reduced for the same reason. Most of my Glocks are old original runs, not Gen 3 or Gen 4, so I have to have something that drastic done.
    I don't recall whether or not you have access to a Ransom Rest to lock the pistol down to confirm it isn't a manufacturing issue. Might be worth taking to a good gun smith with one and find out whether its the gun or the fitting issue.
  38. Oh, Im an ASU fan, but for all the guys I work with in SW Asia who are wearing red hats with a white "A" on it; "Roll Tide".
  39. Before moving the rear sight, look very closely, is the rear sight centered in the sight slot. If it is on the left side then center it.
    Second: Many right hand shooters who place their trigger finger to far in will shoot low left. Low right for left handed shooters. Press the trigger with the center of the first pad, pulling straight to the rear.
  40. Sherlock Glock, I agree with the tirgger being pulled straight back. There are lots of folks who no longer teach to use the pad of the finger on pistol triggers (I recently was made a believer at Sig Sauer Academy during a firearms developement course) and use the underside of the first knuckle so that there is only one moving joint involved. Regardless, with a grip that is too big for the hand, trigger placement and pushing the gun to the left with the tirgger finger is a common result.
  41. Bama, since your brother has the exact same gun as you do and you're going to trade barrels to isolate the trouble you can also trade slides while you're at it.
    There is a possibility that the slide is the problem.

  42. If the gun doesn't shoot to point of aim from a rest, then the problem isn't the shooter. The gun are broke.
  43. Had similar issue with my g20 long (LWD 6" slide).
    I also had .40 SW barrel which was shooting straight, proving it's not grip issue or internals.
    So I made LWD exchange 10mm barrel and it hits where I aim since.

    Sent from my iPhone using Tapatalk
  44. I heard an old timer at my range one time refer to that phenomenon as "lobstering".
  45. :popcorn:
  46. LOL..... funny how sometimes the obvious get's overlooked; Yes, checking the factory installation of the rear sight is a good start! Wouldn't that be nice & simple. LOL

    Second....I have to respectfully disagree with ANYTHING about changing trigger finger placement, if the OP has been firing many pistols accurately his whole life. This not the time to start trying to change a life long shooting style to try to satisfy just one particular new gun. During high adrenaline self defense, his grip as he has always done with good accuracy, will be automatic and should be left alone. Now if he's never been a good shot or never really had a good consistent shooting style, then that's a different story; Last year for the first time in 40 years I retrained myself to hold my left index finger out along the pistol slide for a more controlled grip. That took a LOT of retraining for it to become an automatic response now. ie; Back in the revolver era of the 1970's it was common to simply cup your left hand around your right hand.