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Discussion Starter · #1 · (Edited)
Good afternoon, gents, new member here in search of help fixing a badly canted sight on Yugo underfolder.

I may have put this info request in the wrong forum? Please advise and I will try to put it in the right place.

At 25 yards my bullets hit 5 inches high and 5 inches to the right. Let me start by saying that I paid one of Atlanta's better known gunsmiths $125 a couple of years ago to fix this, got it back and did not have a chance to shoot it for a year, yeah, it has been that kind of couple of years. When I got it out to the range, it shot off the paper and cardboard at 50 yards. I think I even took it back to him. He gave it back later claiming fixed, and it was unchanged.

I want to love this weapon and have concluded that I have to fix it myself. I read a lot of good info around the net stating that I needed to drive out the pins, use some form of big force to twist it to straight up, redrill the holes and reinsert the pins or factory sized pins, or better, oversize drill the holes and obtain pins to match, the easiest being 1/8 because 1/8 drill stock is available from which to make pins.

It all started out better than expected... the pins came right out with mild pounding. They did not look as if they had been removed... they were flush ground and blued during the remanufacture by Century, and no indication they had been out since then.

I bought a hard phenolic plastic, notched "barrel guide" for my hefty bench mounted vise. The barrel holder has a 90 degree vee notch in it approximately 5/16 inch deep so the barrel contacts only at four, fairly narrow spots. It had to be cut down to approximately 2.25 inches wide to fit between the sight block and end of gas block. I wrapped the barrel with 220 grit sandpaper out, toward the barrel holder.

Here is the punch line: even after tightening the vise on barrel with a 24 inch "cheater" bar pipe over a 3/8 inch socket extension inserted through the sight, the barrel just moves. I am afraid of collapsing the barrel if I lean on the cheater bar to tighten the vise any more. Is that possible to collapse a barrel with a vise? Should I attempt to make a barrel holder out of oak by drilling with a drill press (I have one) so that there is more surface area for friction to hold the barrel? Once the barrel is secure, should I perhaps use an oak block and hammer to whack the site with an impact vs. slow application of torque with 3/8 shaft and long cheater bar pipe? Thinking that an impact whack may have better chance of moving sight before moving barrel.

Thanks in advance for your thoughts and input.

shovel99
 

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Use a mallet to tap the sight over, don't try to pull on the sight. If this fails to move it, apply some heat to the FSB and then tap on it with the mallet.
 

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Was it ever sighted in? It may have been straightened but not sighted in

If it was sighted in then at what distance

Sent from my XT1650 using Tapatalk
 

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+1., if it was sighted in how far from center is the sight post to attain a zero?

Do not do any inordinate striking of the parts. If it is interference fit properly the front sight block will take a lot of force to move. It is better to press it off partially to move it and the align and press back but use a bore sighter and test fore to verify alignment before pinning the FSB back into place.

What type/model is this AK?
 

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Discussion Starter · #5 ·
Thanks for the reply and advice.
Heat as in propane torch? Bathe for a few seconds a couple of times and pop again with the mallet? Do I use an oak block to bear on the flat side of the SB so I don't bend the ears?
 

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Discussion Starter · #6 ·
Thanks for the reply. As stated above, I gave to professional gunsmith to 'fix the sights' which I presumed then was 'sight in and or use a bore sight.' Came back off the cardboard over 10 inches at 50 yards. I learned that in fairly firm tapping with rubber mallet, with pins removed, that sight did not move. I had bought a cheap $10 ebay chamber cartridge laser bore sighter and after the first go after getting the the sighter in place, it aligned perfectly in my basement with the gun clamped to my table saw. I thought.. hurrah, I am in! And then shot the same way off place at 25 yards. The guys at the range suggested marking the cartridge sighter and try it at 12, 3, 6 and 9. The funny thing is that one of the four was dead on where the sight was pointed.. and the others varied and were mostly 5 inches off and or down not particularly consistent with the actual results.
 

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What ammo are you using?

And again. Fixing the cant and sight in are two different things.

Sent from my XT1650 using Tapatalk
 

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Discussion Starter · #8 ·
Thanks AK Blue, I am starting to get the hang of using the BB system.
When you say "press off" and "a lot of force to move" when a long crowbar and hammer blows to a long crowbar have produced no motion, I presume you are talking about a machine shop with a hydraulic press? Is the average machine shop going to have the tools to hold a weapon barrel and apply thousands of pounds of force to remove this thing?
I understand not wanting to pound it to pieces, but am inclined to try the heat and moderate tap program, and if that doesn't work try to find a qunsmith who has actually done this in the Atlanta area. Does anyone here know of someone in the Atlanta Metro who has done this correctly and would like to be paid to do mine?
Thanks!

+1., if it was sighted in how far from center is the sight post to attain a zero?

Do not do any inordinate striking of the parts. If it is interference fit properly the front sight block will take a lot of force to move. It is better to press it off partially to move it and the align and press back but use a bore sighter and test fore to verify alignment before pinning the FSB back into place.

What type/model is this AK?
 

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Discussion Starter · #9 ·
Been there, did that first, and am using PPU Partizan Soft Points

Sorry if I sound a bit abrupt, but I assumed everyone here on an AK board would know that an AK that misses point of aim at 25 yards by 5-6 inches and 10 inches or more at 50 yards cannot even begin to be "zeroed" or sight adjusted so that the bullet hits POA. I saved a few key strokes in my discussion of history that started with attempting to adjust the front sight to put the bullets at POA. It was after exhausting that option to one complete side that I became painfully aware of the 5-10 degree crooked tilt to the left of my brand new $600 Yugo M70AB paratrooper model.

I did not learn that this AK problem had a formal name "front sight cant" and that it was extremely common until web searches to fix the problem.

I am using PPU Partizan Brass Cased Soft point which is extremely accurate in my Mini 30, especially after installing a reduced gas bushing.

Thanks

What ammo are you using?

And again. Fixing the cant and sight in are two different things.

Sent from my XT1650 using Tapatalk
 

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Sorry if I sound a bit abrupt, but I assumed everyone here on an AK board would know that an AK that misses point of aim at 25 yards by 5-6 inches and 10 inches or more at 50 yards cannot even begin to be "zeroed" or sight adjusted so that the bullet hits POA.

Thanks
No exactly. Sights are put on but not necessarily set. Most of my AKs weren't even close to paper at 25 yards when I got them.

But you didn't mention the fact that you had the sights moved all the way as far as they would go.

Sent from my XT1650 using Tapatalk
 

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It sounds like your bore in non concentric. This is another problem whereby the front sight block may be square to the barrel OD but the bore is not concentric to the barrel diameter.

Yes a hydraulic press and press plates to move/remove the FSB. Though a open end wrench on press plates will work to press the front sight base off partially or until it can be moved.

Shooting to confirm the sight post can be centered and hit POA before pinning is the final test.

Video about bore concentricity.
 

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Discussion Starter · #12 ·
Cheap laser bore sight was floating...

Thanks, I will take a look. The cheap laser bore sight was "floating"... did not fit correctly or snug, so when I placed it in the chamber, it moved and gave me multiple POA's "wobbling" it between the extremes gave me a "range" of where true bore sight is.

I believe my sight moved closer to accurate on latest whack. I plan to soak it in Aerokroil and give it one more whack before trying it one more time at the range. Hopefully moved enough to get on paper with sight adjustment.

It sounds like your bore in non concentric. This is another problem whereby the front sight block may be square to the barrel OD but the bore is not concentric to the barrel diameter.

Yes a hydraulic press and press plates to move/remove the FSB. Though a open end wrench on press plates will work to press the front sight base off partially or until it can be moved.

Shooting to confirm the sight post can be centered and hit POA before pinning is the final test.

Video about bore concentricity.
 

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Be sure the rear sight ladder is not canted or bent. This can be an issue on some of the Zastava kit builds as they sometimes took a hit on the sight ladder area and it is bent tone side.

Good luck beating n the FSB. If it was a loose fit to start when built it may move for you.

The use of the 90 degree squares or any blocks can help determine if the FSB is moving or not.
 
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