Glock 17 POI Issues

Discussion in 'General Glocking' started by DirectDrive, Sep 5, 2018.

  1. DirectDrive

    DirectDrive

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    So I have two home builds. OK, kill me.
    One is a G19 with a KKM barrel and it just rips up the bull at 50 feet.
    115gr and 124gr Blazer Brass

    The other is a G17 with a KKM barrel as well.
    I like to shoot 115gr Blazer Brass (inexpensive) and the G17 is way low left with this.
    My front sight is to tall and I have a shorter one en route.
    But this barrel will never like 115gr Blazer Brass.
    124gr I can probably make work.

    It's just strange how the G19 kicks a$$ on the G17.
    I wonder if I should send that barrel back or just adjust to it ?
     
  2. CDR_Glock

    CDR_Glock

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    Bore sight both guns. That is what I’d do. Then check/confirm zero on a rest.

    Point of impact between the two loads is different.

    What distance are you shooting?


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  3. DirectDrive

    DirectDrive

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    50 feet
    I'm shooting both side by side so I think it's a fair assessment of the performance of each barrel.

    I can pick up that G19 and know that I'm going to tear up that bull.
    With the G17 not so much.
     
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  4. CDR_Glock

    CDR_Glock

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    How big is your target?


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  5. DirectDrive

    DirectDrive

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    It's the Birchwood Casey Shoot N See so about a 3-1/2" bull or so.
     
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  6. CDR_Glock

    CDR_Glock

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    The rear sights could be off.

    Something to check.

    I shoot my 17 more accurately and faster than my 19. I have the 17, 19 (2 of them in Gen 4, 1 Gen 3), 19X, 34, and a 23.3, 30.3, and 30S.


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  7. DirectDrive

    DirectDrive

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    I do know that I have to push the rear sight to the right a bit and I need a lower sight which is in the mail.
    I'm thinking that this G17 barrel is just quirky and doesn't like 115gr Blazer.
     
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  8. CDR_Glock

    CDR_Glock

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    How’s the factory barrel work out in the 17?

    I never notice a significant difference in barrels between match and factory, in my 19 or 34.

    I shoot out to 25 yards minimum for steel at my club. At home I do 20 yards and in.


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  9. DirectDrive

    DirectDrive

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    It's a home build so I only have the one barrel.
     
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  10. thewoods868

    thewoods868 thewoods868

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    Change your locking block to a lonewolf block
     
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  11. Bren

    Bren NRA Life Member

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    I have not been able to get 115 gr. Blazer Brass to group in any gun, but I'm shooting it at 50 yards, not feet, so I'd expect it to be more stable under 25 yards.

    However, "low left" isn't an ammo issue. If the ammo is grouping, you either need a sight adjustment or a shooter adjustment. Could be the sights are off, or it could be the difference between how you shoot the 19 and 17 is about having more pinky on the grip, so your grip milking is worse on the longer grip. I have suspect that is why so many people can outshoot themselves using a G26 or a G17, which seems illogical at first.
     
  12. WeeWilly

    WeeWilly

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    It could be any number of things, almost no chance it is the barrel.

    I would adjust the sights to get your POI where you want and call it good.
     
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  13. DirectDrive

    DirectDrive

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    It's odd how the damn G19 shoots BB 115gr and BB 124gr equally well.

    Interesting how the smaller pistols can shoot better due to grip surface.

    Disregard the upper right group.
    Bullseye is the G19 with BB 115gr
    Lower left is G17 with BB 115gr

    I have a .235 tall front sight on the G17
    Going to try a .185 tall front sight next time on the G17
    And tap the rear sight over a bit if I can't resolve windage with grip adjustment or an ammo change
    It is .010" the wrong way presently (not much)
    9-5 Target.png
     
  14. harold63

    harold63 I'm not retired

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    At 50', any ammo you shoot will group in the same place. Pistol ammo doesn't bounce all over the target like diff brands of rifle ammo does 100/200 yds out. Either the barrel fit makes it shoot low left or the sights are off (or both).
     
  15. Fatboy2001

    Fatboy2001

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    I would try different ammo before I sent the barrel back. All of my KKM's have been excellent.
     
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  16. Bren

    Bren NRA Life Member

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    You don't say it shot poorly, you say it shoots low and left. Poorly would be not grouping. Grouping in the wrong place is a zero issue or a shooter issue. Guns, especially when you have changed the barrel and sights, are not expected to magically shoot where you aim the sights, unless they are zeroed to the gun.
     
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  17. sciolist

    sciolist On the Border

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    At 50 feet, you should be able to see the sights lift and the hit form simultaneously. So with respect to the target in Post 13, if you see the sight picture lift from 6:00 on the bullseye or center of bullseye, and then the group forms down there at 7:00, should be pretty obvious what you need to do. That's assuming you want the gun zeroed at 50 feet.

    Dropping 5 hundredths on the post is a huge change. My experience with the G34 is that 1 hundredth of post equates to about 1 inch of elevation at 20 yards.
     
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  18. sciolist

    sciolist On the Border

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    Agree.
     
  19. DirectDrive

    DirectDrive

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    You're right.
    I have a simple sight adjustment to do for my chosen ammo.

    My sights are TTI fiber optic.
    Front:
    .235T x .115W
    Rear:
    .245T x .125W

    Sevigny has a front .215T x .115W
    Dave said that -.020 wouldn't be enough
    So I used the Ameriglo sight calculator and it spit out -.043
    So I'm a little more than that at -.050
    I guess I'll find out when the sight gets here.
    It's a Warren Tactical .185 x .115
     
  20. sciolist

    sciolist On the Border

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    For my production 34's, I use a .245 x .125 Dawson FO front and .130 Sevigny Comp rear. I zero at 20 yards.

    .245 seems to be conventional wisdom for a production 34. The G17 prints pretty similarly for me. I use .230 on the G19 and a .205 on the G26. Conventional wisdom on the G19 would be .215.

    One thing I find in my own shooting is that I tend to present Glocks a bit high, but I also point them a bit low. At speed on mid/far targets those 2 tend to cancel each other out.

    Under stress, when I go to a hard front focus, I tend to disregard the rear sight, which can make the hits go a little low (like 1 or 2 inches at 20 yards, depending on stress level). But shooting groups on a sunny afternoon, the .245 prints fine for me.

    So not to sound like a jackass, but you do need to be sure the gun is pointed in the right place, and you do need to see an appropriate sight picture, and press the trigger like a non-retard. And all of that can be challenging under stress. :)

    But when I get bad hits, it's generally because I wasn't pointing the gun in the right place when it went off...
     
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