I am seeing a lot of postings by first timers, so I thought I would put together a lessons learned list.   They are in no particular order.  You experienced guys feel free to add to the list.


The selector stop tab may try to disappear when removing the trigger guard rivets.  So keep an eye on it.

Be sure to get the selector stop plate on with the tab pointing toward the selector side.  

Check the side to side alignment of the gas piston with the gas port before riveting.  Misalignment can be caused by an out of tolerance receiver or incorrectly placed rivet holes.

An underfolder won’t go together the first time, regardless of the order that you assemble the parts.  Thats just the way it is.  But for starters, the pin order is:  the pin that gets hidden in the right side of the receiver, the pin in the nut, the pin that retains the pushbutton.

When disassembling the underfolder (because you didn’t get it together right the first time), the pushbutton will shoot across the room and hide when removing the retaining pin.  Anyone have an extra push button they would like to sell?

Be sure to get the top cover fitted so that it goes all the way down in the back  and the cover release button sticks all the way out.  Otherwise, the cover may come flying off and hit you in the forehead when you fire the gun.

Make sure both of the hammer spring legs are resting on the trigger assembly.  Otherwise the trigger wont reset reliably.

If your trigger hangs up at the very first of the travel, check for interference with the trigger guard rivet.

The trigger guard should point toward the pistol grip, not the mag well.  Remember what a pain it is to get those 4 rivets out?

Believe it or not, pulling the barrel saves time.  Even if you screw build.

Use antiseize on the barrel and barrel pin.

A chirping sound when drilling the rear trunnion rivets means the bit is about to break.  

When adjusting the front sight.  Imagine pointing the bore line at the target.  Now move the sight toward the hole the bullet made.

You can remove the top handguard wood by rotating it 180 degrees on the gas tube.

An empty 22 cartridge can be used as a makeshift trigger pin sleeve.  A large paperclip can be formed into a makeshift shepherds hook (pin retainer).

Krylon or Duplicolor, not Rustoleum.

That funny looking spring and the extra little parts are for the full auto fire control group.  You do know that it is illegal to install these, right?  Oh, the little hook shaped thing is your disconnector.  Install it and the little coil spring in the trigger assembly.  If you are going to reuse the original disconnnector, grind off the tab on the back of it first.

If a 223 (5.56) is loaded into a mag by mistake, it will chamber and fire, but not extract.  It will look real funny when you get it out.

The muzzle break is supposed to be tilted and the gas piston is supposed to wobble.

The bolt carrier has to be removed before the top handguard can be removed.

A yugo (CFS) underfolder trunnion is 1.2mm more narrow than a standard trunnion.  That is, it will need to be shimmed to fit a standard 1mm receiver.

That little tiny spring that goes between the trigger and disconnector is very important, don't lose it.

Use the Dremal wisely, it is easier to remove metal than add it.

Buy go and no go gauges. No excuses.

Cheap drill bits will cost you more in the long run.

Don't touch the refinish job yet, unless you want to do it again.

When drilling your holes in the receiver, the front trunnion goes into the receiver with the two top rivet holes toward the front of the receiver and the lower back hole near the mag well, not the reverse.....

Don't drink (too much) and build. (see above)

So very tagged.

Super Tagged Thanks for the heads up suggestions.

When installing the hammer, pull the spring legs over the hammer ears, and cross them, holding them in place.  It is 2000% easier to install the pin on the hammer with out spring tension.

General question here-
What is the reason to remove the barrel from the front trunion? Can't you just  keep them together and cut the old receiver stub off and rivit onto the new receiver?

I was reading pookies website and he was hinting into something like that.  that barrels gotta be harder than the rivet.  but then again if you swing for the fences and egg the barrel you cost yourself some cash.  I have 10 kits on their way and plan on taking the barrell out of all 10 to build.  then again if a 12 ton press wont press the pin out then we will see how well the barrel will form a head!  

Quoted: General question here- What is the reason to remove the barrel from the front trunion? Can't you just  keep them together and cut the old receiver stub off and rivit onto the new receiver?

I included the "remove barrel" item in the list because most newbies waste a lot of time and effort trying to figure out how to avoid pulling the barrel. (and this once included me)  There are countless threads on this and other boards where a guy who recently bought a kit just can’t seem to be convinced that he should pull the barrel.  I don’t mean to be rude, but this is an old argument. If you do a search I think you will see what I mean.  If you can’t get your answer there, please start yet another “why do I have to pull my barrel thread.”

I have a couple more....  

Always install the trigger guard first, install the friont trunion BASED on mag fit between front trunion and trigger guard EVEN if your receiver is predrilled for trunion holes....  Egging and fixing front trunion holes is MUCH easier then adjusting the trigger guard latch plate or front trunion if it is out of spec....

The same applies for the rear trunion...  Get the barrel back in the front trunion and get it headspaced...  Then place the rear trunion based on fit for the top cover...

If you screw these up once and have to fix it, you will NEVER make the mistake again...  I sure have not!

Quoted: I have a couple more....   Always install the trigger guard first, install the friont trunion BASED on mag fit between front trunion and trigger guard EVEN if your receiver is predrilled for trunion holes....  Egging and fixing front trunion holes is MUCH easier then adjusting the trigger guard latch plate or front trunion if it is out of spec.... The same applies for the rear trunion...  Get the barrel back in the front trunion and get it headspaced...  Then place the rear trunion based on fit for the top cover... If you screw these up once and have to fix it, you will NEVER make the mistake again...  I sure have not!

I totally agree with this, but it looks like the tutorials that folks want pegged on this board show it done... front trunnion, rear trunnion, mag catch... I think it should be mag catch, front trunnion, rear trunnion as well... much easier in the long run...

I also think refinishing is better when the rifle is complete, then you don't have to worry about 'touch ups".

I can only add one so far.....

If it takes more than 20 minutes to press out the barrel pin, your better off to drill it out and replace it.

SRM

Quoted: I am seeing a lot of postings by first timers, so I thought I would put together a lessons learned list.   They are in no particular order.  You experienced guys feel free to add to the list. The selector stop tab may try to disappear when removing the trigger guard rivets.  So keep an eye on it. Could you not have posted this sooner..  Anyone know where I can get a new selector stop ? Be sure to get the selector stop plate on with the tab pointing toward the selector side.   Check the side to side alignment of the gas piston with the gas port before riveting.  Misalignment can be caused by an out of tolerance receiver or incorrectly placed rivet holes. An underfolder won’t go together the first time, regardless of the order that you assemble the parts.  Thats just the way it is.  But for starters, the pin order is:  the pin that gets hidden in the right side of the receiver, the pin in the nut, the pin that retains the pushbutton. When disassembling the underfolder (because you didn’t get it together right the first time), the pushbutton will shoot across the room and hide when removing the retaining pin.  Anyone have an extra push button they would like to sell? Be sure to get the top cover fitted so that it goes all the way down in the back  and the cover release button sticks all the way out.  Otherwise, the cover may come flying off and hit you in the forehead when you fire the gun. Make sure both of the hammer spring legs are resting on the trigger assembly.  Otherwise the trigger wont reset reliably. If your trigger hangs up at the very first of the travel, check for interference with the trigger guard rivet. The trigger guard should point toward the pistol grip, not the mag well.  Remember what a pain it is to get those 4 rivets out? Believe it or not, pulling the barrel saves time.  Even if you screw build. Use antiseize on the barrel and barrel pin. A chirping sound when drilling the rear trunnion rivets means the bit is about to break.   When adjusting the front sight.  Imagine pointing the bore line at the target.  Now move the sight toward the hole the bullet made. You can remove the top handguard wood by rotating it 180 degrees on the gas tube. An empty 22 cartridge can be used as a makeshift trigger pin sleeve.  A large paperclip can be formed into a makeshift shepherds hook (pin retainer). Krylon or Duplicolor, not Rustoleum. That funny looking spring and the extra little parts are for the full auto fire control group.  You do know that it is illegal to install these, right?  Oh, the little hook shaped thing is your disconnector.  Install it and the little coil spring in the trigger assembly.  If you are going to reuse the original disconnnector, grind off the tab on the back of it first. If a 223 (5.56) is loaded into a mag by mistake, it will chamber and fire, but not extract.  It will look real funny when you get it out. The muzzle break is supposed to be tilted and the gas piston is supposed to wobble. The bolt carrier has to be removed before the top handguard can be removed. A yugo (CFS) underfolder trunnion is 1.2mm more narrow than a standard trunnion.  That is, it will need to be shimmed to fit a standard 1mm receiver.

Hey Jake,  I know the feeling.  I ground the selector stop off my first build.  I keep thinking I will try welding a tab back on, but never get around to it.  If you use a dremel cutoff wheel to grind a divit (or whatever they call it) at the lower selector position, like on the military receivers, you wont miss the stop (much).

when building a yugo
the orig pg block must be used
if nothang else you have to cut a chunk of it and use it for a spacer on your trigger guard
or when you get done the trigger wont fit

of coarse you dont notice this till the rifle is already refinished and ready to be testfired

is the selector stop/selector stop plate really all that important ?  The older-style milled guns don't have it.  I looked at the trigger guard from the Type 3 kit I have and there's no stop.  

the milled rec has a pin in the side (gone after demill)
that servs as a select stop

another add to the list....
Dont believe every thing you read on a "build it your self forum"...  I bet 25% of the people who post here are armchair  builders who never built anything,,

^^^^^ So true

Quoted: is the selector stop/selector stop plate really all that important ?..

A stamped receiver will not  feed without the selector stop in place.

Always install the trigger guard first, install the friont trunion BASED on mag fit between front trunion and trigger guard EVEN if your receiver is predrilled for trunion holes.... Egging and fixing front trunion holes is MUCH easier then adjusting the trigger guard latch plate or front trunion if it is out of spec.... The same applies for the rear trunion... Get the barrel back in the front trunion and get it headspaced... Then place the rear trunion based on fit for the top cover...

I totally agree with this, but it looks like the tutorials that folks want pegged on this board show it done... front trunnion, rear trunnion, mag catch... I think it should be mag catch, front trunnion, rear trunnion as well... much easier in the long run...

I mentioned this in that thread, a couple of days ago.

Quoted: Quoted: is the selector stop/selector stop plate really all that important ?..   A stamped receiver will not  feed without the selector stop in place.

Huh?

Well, I suppose that if the stop plate were omitted entirely, the rear of the mag would sit too high and cause feeding problems.  Is that what you mean?  The selector stop tab isn't really necessary. It just keeps the selector from rotating off the bottom of the receiver.

Quoted: Well, I suppose that if the stop plate were omitted entirely, the rear of the mag would sit too high and cause feeding problems.  Is that what you mean?

Exactamundo.

I have read several threads on the various gun forums regarding home builders, who built rifles that would not strip a round, only to find out they omitted the selector stop.

I also remember one well respected builder, though I can't remember who, stating he would not assemble a customers kit into a rifle, with a used selector stop.
They would need to spring for a new one,if they wanted him to do the build.

I've always questioned this, because I never had a problem with a used one.

actually, I build my yugo on a modified OOW, and it would not feed WITH the selector stop in place. I had to install it without, then add a little tab of metal on the underside of theTG to act as a selector stop.  I have noticed OOW tends to let the mags be a little low.  mostly it's not an issue, but I have seen two that had the mag to low to feed if the selector stop was installed.

The smaller the part, the harder it is to replace.

All small parts on the AK are concrete soluble

Quoted: The smaller the part, the harder it is to replace. All small parts on the AK are concrete soluble

Quoted: when building a yugo the orig pg block must be used if nothang else you have to cut a chunk of it and use it for a spacer on your trigger guard or when you get done the trigger wont fit of coarse you dont notice this till the rifle is already refinished and ready to be testfired

this is true of the M92 krinks also,...i spent a good 10 min. saying W.T.F. to myself,. funny how they make the pistol grip nut.