Author Topic: Sight loose... What size Allen key?  (Read 482 times)

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Offline bsand

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Sight loose... What size Allen key?
« on: February 15, 2017, 08:26:20 PM »
Well I was dry firing yesterday, noticed that my rear sight was way out of alignment. I purchased this shadow (91030) from you guys back in December.
Now I was planning on fixing it myself, but I can't even get the Allen screw to loosen. The supplied Allen key (with the gun) doesn't work nor does my Allen key. Like it feels like it's grabbing but just ends up spinning and rounding the edges of the Allen key.

What size is the Allen key screw? 




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Offline novacz

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Re: Sight loose... What size Allen key?
« Reply #1 on: February 16, 2017, 12:25:07 AM »
I don't have my hex key set handy at the moment, but I'm almost positive that it takes a 1.5mm wrench

Offline bsand

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Re: Sight loose... What size Allen key?
« Reply #2 on: February 16, 2017, 12:31:24 AM »
Figured it out, took it to the auto shop supply (slide only) and it's 1/16"!

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Offline M1A4ME

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Re: Sight loose... What size Allen key?
« Reply #3 on: February 16, 2017, 07:59:23 AM »
If the inside of the screw is slightly damaged/worn, it might be a good idea to replace it with a new one with nice sharp corners inside.
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline bsand

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Re: Sight loose... What size Allen key?
« Reply #4 on: February 16, 2017, 07:03:41 PM »
No damage has been done to the screw  or sight. Only to my slide as I didn't tape my brass punch and it cracked the poly coat :(

Zerod it today at 25y, only took one adjustment at 10 yards and I was hitting where rear sight was aiming.



My zeroing rig for kicks lol



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Offline bsand

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Re: Sight loose... What size Allen key?
« Reply #5 on: February 20, 2017, 08:27:46 PM »
The gun has czc's competition rear sight. There is only one set screw and it was 1/16". Issue is fixed now, and well I'm going to be getting away from fixed sights as I'm giving carry optics a try.

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Offline angus hobdell

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Re: Sight loose... What size Allen key?
« Reply #6 on: February 27, 2017, 02:07:32 PM »
Part of the problem with the shadow dovetail is that the back portion is shorter "lower" then the front portion.
Under recoil and constant usage the leverage of the sight can potentially stretch the rear "lower" dovetail cut. CZ Comp sight are designed to be tight in the dovetail, so they don't come loose. If the sight is now lose you might need to tighten the rear "lower" portion of the dovetail cut. This is potentially scary fix because it involves punch down the dovetail, but tightening the dovetail really is the best fix.
Angus Duhhhh!

Offline 1SOW

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Re: Sight loose... What size Allen key?
« Reply #7 on: February 27, 2017, 03:15:38 PM »
Right or wrong,  I used a piece of copper/brass (?) .001" feeler gage to shim my loose Comp sight before tightening the screw.  I had to tap the sight in pretty firmly,  but it went in and has stayed put for quite a while now.

P.S.  Always check the hex wrench tip for wear.  Regrind/file the tip if it's getting rounded. Make it flat and sharp edged.
« Last Edit: February 27, 2017, 03:19:28 PM by 1SOW »

Offline bsand

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Re: Sight loose... What size Allen key?
« Reply #8 on: February 28, 2017, 09:31:55 AM »
Part of the problem with the shadow dovetail is that the back portion is shorter "lower" then the front portion.
Under recoil and constant usage the leverage of the sight can potentially stretch the rear "lower" dovetail cut. CZ Comp sight are designed to be tight in the dovetail, so they don't come loose. If the sight is now lose you might need to tighten the rear "lower" portion of the dovetail cut. This is potentially scary fix because it involves punch down the dovetail, but tightening the dovetail really is the best fix.
I should probably mention that the sight was still extremely tight in the dovetail. But it had shifted to the right pretty significantly.

I had installed a Springer precision dovetail mount and well it was like a hotdog down a hallway. My buddy ended up cutting some shims for me. Hopefully it works in life fire.

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