Author Topic: Sights for 75 Pre-B  (Read 2192 times)

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Offline fn1889m

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Sights for 75 Pre-B
« on: August 30, 2016, 02:46:59 AM »
I have replaced the extractor and slide stop spring. It runs reliably. But the sights are small for my old eyes.

The LPA sight, front and rear, seems the easiest option. I can get the pre-B sight. Is the staking solid, once done?Or is a dovetail front sight worth it?

Would appreciate comments from anyone with experience with this sight.


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Offline Earl Keese

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Re: Sights for 75 Pre-B
« Reply #1 on: August 30, 2016, 07:32:46 AM »
Good info in this recent thread. Sight info starts about half way into the reply at the top of page 5.
http://www.czfirearms.us/index.php?topic=81080.0

Offline M1A4ME

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Re: Sights for 75 Pre-B
« Reply #2 on: August 30, 2016, 07:48:15 AM »
I can only speak for my experience with one gun.  A pre B CZ 85.

My front sight had a round tenon.  The tenon is the post on the bottom of the sight that sticks down into the slide and is "staked" in order to hold the sight in place.

The LPA adjustable sights I bought for my pistol were for a Pre B type CZ 85 or CZ 75.  However, the tenon on the front sight was rectangular and pretty thin.  The tenon was too long to fit in the round hole and too narrow to fill the hole side to side when shortened enough to fit the hole front to back.  I elected not to use it for a couple of reasons.  One was the slop between the tenon and the hole in the slide/bushing (on the Pre B guns the tennon also holds the bushing in the slide, so there is a hole in the top of the barrel bushing the tennon sticks down through).  The second was the LPA sight did not have a portion of the sight that fit down into the long slot on top of the slide to also give the sight some strength if struck from the side of the sight.

I bought a 1911 front sight with a fiber optic filament in it.  That tenon was a large square too big to fit the round hole.  I had to file the tenon round to make it fit.  It also had the portion of metal, under the front sight base, that fit down into the slide to make the front sight stronger to side to side bumps/knocks.  I had to file just a small amount of metal off the side of that part of the sight to get it to seat down in the slide, but tighter is good (in my mind).

You may be able to find a gunsmith who would take on that job.  No idea what the cost might be.  I like to tinker with my stuff so I did it myself.

I had to modify a 1911 front sight staking tool, I made my own tip (the part that impacts the tenon and swells/expands it to fill up the hole and keep the front sight in place) and I bought some of that black Loctite that people tell you never to use because once you put it on something you'll never get it apart again (that was the idea, permanent installation). 

I put the black Loctite in the hole in the slide (from the top only), put some on the sight (tenon and the portion that sits down in the slot in the slide) and staked the front sight in.

It's been to the range just once and I only fired about 30 or 40 rounds through it to sight it in.  It was hitting low/left with the sights as installed.  Took 4 or 5 clicks to move the group right and about 6 or 7 to move it up at 13 yds.

I'll have to put a lot more rounds through it before I'm confident the front sight is there to stay.  I've had issues with front sights on a 1911 in the past.  Gunsmith installation, sight came loose, took it back, sight came loose, had the guy silver solder it (which discolored the bluing on the slide) and that time I completely lost it out on a sandy/rocky range.  This time I figured I'd just do it myself, sure couldn't do any worse.

Good luck with yours.  I'm not a fan of fiber optic sights but I've got to admit it sure helps me see it quicker/better.
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 fn1889m

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Re: Sights for 75 Pre-B
« Reply #3 on: August 30, 2016, 05:12:01 PM »
Based on the comments, I would probably not use the front staked sight from LPA. Will check with CZC about options.

Offline jimkaray

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Re: Sights for 75 Pre-B
« Reply #4 on: September 01, 2016, 02:46:29 AM »
I recently had the LPA sights installed on my surplus pre-b. About 50-60 rounds in the staked in front sight started coming loose before finally coming off. I'm having the slide milled for a 'standard' site and will be adding a fiber optic. Since I lost the front sight I bought another set of LPA's before I decided to go the milling route. They are avalilble cheap if you decide to go that route:)

Offline fn1889m

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Re: Sights for 75 Pre-B
« Reply #5 on: September 01, 2016, 10:37:53 AM »
Who is doing the work, and are you milling the same slot as the B model? With a cross pin to hold the bushing?

Offline krehmkej

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Re: Sights for 75 Pre-B
« Reply #6 on: September 01, 2016, 11:53:32 AM »
Same issue here.
Checked with CZ Custom.
Milling for the new style cross pinned sight would be prohibitively costly.
They recommend milling for a 1911 type dovetail.
-jwk-

Offline fn1889m

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Re: Sights for 75 Pre-B
« Reply #7 on: September 01, 2016, 10:21:10 PM »
They recommend milling for a 1911 type dovetail.

How would the bushing be retained?


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Offline Earl Keese

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Re: Sights for 75 Pre-B
« Reply #8 on: September 01, 2016, 10:47:56 PM »
They recommend milling for a 1911 type dovetail.

How would the bushing be retained?


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The bushing is retained by the sight, the dovetail is cut deeper than the oem cz pinned version.

Offline M1A4ME

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Re: Sights for 75 Pre-B
« Reply #9 on: September 02, 2016, 06:57:28 AM »
Is the top of the slide thick enough to mill it for a P07/P09 type sight that is locked in by a combination of friction and a set screw?

I guess the other question would be whether or not the set screw would line up with the hole in the barrel bushing or not.  Of if you'd have to drill/tap a new hole in the slide for the set screw, then use a longer set screw to go through the slide and into the new hole in the bushing, but stop short of sticking through the bushing to make contact with the barrel.  That should be easy to figure out if the slide is thick enough in the first place for the P07/P09 type front sight.
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.

SPO1SHADOW

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Re: Sights for 75 Pre-B
« Reply #10 on: September 02, 2016, 05:41:01 PM »
$60.00 bucks to mill the front is a deal! If you don't have them do anything else it would be well worth that cost to get a front sight that you didn't have to worry about.

Offline Earl Keese

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Re: Sights for 75 Pre-B
« Reply #11 on: September 02, 2016, 05:57:04 PM »
$60.00 bucks to mill the front is a deal! If you don't have them do anything else it would be well worth that cost to get a front sight that you didn't have to worry about.
This.

SPO1SHADOW

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Re: Sights for 75 Pre-B
« Reply #12 on: September 02, 2016, 06:14:11 PM »
While you are at it, pop a 10X bushing in the slide before you send it out to be milled. When it gets back slap your LPA in the rear, go to Dawson Precision pick out the .150 tall sight of your choice, beat that into the front dovetail and you are in business Mister!

Offline schmeky

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Re: Sights for 75 Pre-B
« Reply #13 on: September 04, 2016, 10:17:53 PM »
We mentioned on another thread there is very good option for milling in a 1911 style front sight that does not require a deep dovetail cut to retain the bushing (although this works well). 

We have found if you remove the old tenon post front sight and do a .060" depth cut from the top of the slide (the height of a 1911 style F/O sight base), you can punch out the remaining tenon post.  Then we do what we call a "half tap" of the hole with a 3 mm x .05 mm tap.  We then grind down a 3mm x 3mm set screw to 3mm x 2mm. 

We use red Loctite on the 3mm x 2mm set screw and the "half tap" threads make for super tight thread fit, with the screw going into the bushing more than enough to retain it securely in place, just like the old tenon post did.  Screw the 3mm x 2mm down into the slide until it is flush with the top of the new .060" cut and fit the new 1911 style sight.

This method will even allow you to use a newer bushing if you want improved accuracy. 

SPO1SHADOW

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Re: Sights for 75 Pre-B
« Reply #14 on: September 04, 2016, 10:21:43 PM »
That sounds like just the thing. What does it cost if only the sight mod is done and no refinish or anything else?