MCKAY Bolt, w/pics . Is this Normal?

[Funner]

I started this post off of the other Mckay "instock" thread, to see if the Machine marks were normal.

-The rails of the bolt look like a file.
-The sides of the bolt all around have heavy machining swirl marks.
-The bolt face has machining gouge swirls on it.
-The inside of all the firing pin and recoil rod holes have heavy machining ridges though out.

What are your thoughts?
Thanks

 

[Funner]

Here are a few more pics.

 

[chipster]

I suspect at the end of the day McKay will be most interested in whether it runs. Does it work?

 

[root]

Typical wore out junk tool marks.
1st pic
Shot end mill used to mill and face the end of the bolt. probably chipped or heat warped due to being dull.

The 2nd pic is a beat to snot out .005 +/- ( being nice here or more) has a chipped tooth or is already smoked/warped causing the gouging and swirls.
And can be cleaned up with a fly cutter, or lathe grinding attachment, or just left as is.

Same with the last drill pix. ( to much of a spiral to be boring bar marks)

Do you have the gauges to check for runout on those hogged out world of swirl holes?
betcha they are out pretty bad from the deflection of the bit being dull.
On the bright side they should hold carbon well if they look that deep in a photo.

I'd probably not worry about it to much as long as the gun runs or you want the bolt to look MINTY, NIB, Daisy Fresh!!! ( sorry finally had to do it)

As long as the gun runs you can just leave it and show everyone what a fine quality machine job they do for the price they charge.
If the gun does bind up I will bet ya a dounut that's its the recoil and firing pin holes and that runout is causing them to bind.

I will say it looks better then my factory saiga 12 did when I bought that NIB (LOL).
that S12 of mine looked like a drunk Rusian hooker was gnawing on it for a 20 spot under the dust cover.

That gun ran fine in stock config. straight out of the box.
Took some work once I chopped it to 12 inches and it was all crappy wore out tool marks that had to go.
then the gun went right back to running as it should even the cheapo wally world junk.
Only mods were removing the Russian hooker teeth marks.

Gun has NOT been converted to PG yet and like I said accept the addition of a stamp and the loss of 7 inches of barrel it's 100% Russian factory IZHMASH
not broke in with less then 50 rounds down the pipe & 100% reliable now.

That should give you a idea of what dead tooling & tool chatter can do for/to a gun.

Have you shot your bolt yet? does it work?
I'd like to know.

Rich

 

[Funner]

I have not shot it yet. I only put in my Norinco and McKay to see what it felt like. It feels like it looks.
I got slammed with work so it will be a bit before I can try it out.
Thanks. I will let you know.

 

[Captain murrica]

i would ask the manufacturer it that's normal acceptable before I threw it in and ran it. Could get the hey buddy sorry, but it's used now answer. Never used them so may be great folks, but people are wierd these days. Anyway I hope your gun works whatever you end up doing.

 

[root]

I'd be more concerned with does it work?
and no one is going to know that until you try it.

Will it feed rounds due to the gouges from the tooling on the bolt face?
will the bolt cycle back and forth with those spirals in the through holes? Or will it bind on the recoil spring/rod, firing pin or both?

If it does work I'd just leave it as is. any correction done to it will bring it closer to out of spec. and also remove the finish.
You don't fix tool marks like that and expect to keep the finish also.
Cleaning the bolt face may bring it out of spec enough to not fully seat/chamber rounds

all of this is probably a non issue. But then again every time a dremmel or other mill removal tool touches the bolt for a correction it makes it smaller in some way.
how many more thousands can be taken off before it's NFG?

I don't know, as I don't know what it measures now to compare to the prints I have or my Troy @ BarrelXchange converted FA to semi bolt.
Now there is a guy who takes pride in his work.


Ya might want to see if BarrelXchange or BWE have any converted uzi bolts in stock and just send that one back for a refund if they do.
Or see if they want to exchange it for a properly finished bolt. by that I mean cosmetics. Again it may not be out at all, or out enough to even matter and work as is.
Truth is no one will know until you try it.

Rich

 

[Funner]

I'd be more concerned with does it work?
and no one is going to know that until you try it.

Will it feed rounds due to the gouges from the tooling on the bolt face?
will the bolt cycle back and forth with those spirals in the through holes? Or will it bind on the recoil spring/rod, firing pin or both?

If it does work I'd just leave it as is. any correction done to it will bring it closer to out of spec. and also remove the finish.
You don't fix tool marks like that and expect to keep the finish also.
Cleaning the bolt face may bring it out of spec enough to not fully seat/chamber rounds

all of this is probably a non issue. But then again every time a dremmel or other mill removal tool touches the bolt for a correction it makes it smaller in some way.
how many more thousands can be taken off before it's NFG?

I don't know, as I don't know what it measures now to compare to the prints I have or my Troy @ BarrelXchange converted FA to semi bolt.
Now there is a guy who takes pride in his work.


Ya might want to see if BarrelXchange or BWE have any converted uzi bolts in stock and just send that one back for a refund if they do.
Or see if they want to exchange it for a properly finished bolt. by that I mean cosmetics. Again it may not be out at all, or out enough to even matter and work as is.
Truth is no one will know until you try it.

Rich

Thanks Rich.
Do you happen to know how much Barrelexchange Tony charges for a bolt conversion.

 

[root]

No I don't I bought a 40 S&W FA to semi conversion back in 2003 from him and still use it today in my IMI as a 9mm bolt
Never got around to the 10mm or 40 conversion.
there is a thread in the mactalk forum with a a pic of the bolt.

Rich

 

[Funner]

I will be returning the Mckay bolt. The firing pin carrier also has quite a bow outward. The bottom of the carrier also arches up more than 1/16th.

 

[root]

Sounds like you don't have much in the way of tooling ( not meant as a slam)
So here is a way to check your bow.
Use a mirror or small pane of glass and lay the bolt on it. It's a cheap inspection plate substitute. ETA: lay a crisp unwrinkled 8.5x11 printer paper on the glass then the bolt.

then with a flashlight shine the light where the bolt meets the paper you will see if and how warped it is. a regular sheet of printer paper is around .004 a rolling paper is around .002

you can also skip the light and paper on the glass and just stick the bolt on the glass and go down the edge with the paper seeing and feeling where it goes under and get stuck.
MAKE SURE THE GLASS IS CLEAN! eiter way.
Use a cotton ball and rubbing alcohol to clean it.

If you see light out the other side you have a warp. you can use a piece printer paper or rolling paper to find about how much if you don't have feeler gauges. This will give you cheap indicators with no money invested.
Just keep stacking the paper and adding the .004 or .002 until it won't slide anymore.
POOF! you now know how much warp you have in the bolt body.

Little harder to find the amount of deflection on the holes without the proper stuff but if you can see them with the eye just by looking I'd bet they are 20-30 K out.

I don't normally notice runout with the eye until around .005 and that's looking for it.
20-30 K I can spot like you did. With a "WOW that's off" all the way from across the room.

So my advice would be to send it back and get a good one or your money.

I'm not a machinist, just a guy that owns his own machines and has a idea how to use them.
Should be picking up a Atlas shaper soon from the same guy I bought my lathe from.
After that a 3D printer and I'm pretty much got a cottage industry machine shop here.

Rich

 

[Funner]

I have calipers, feeler gauges, etc if I wanted to get exact. I could clean the bolt up to get it running.

After tax and shipping, over $300 was spent. There is no reason additional machining should be necessary. The firing pin won't even go freely into the firing pin hole. Something like this, the money needs to be refunded, or replaced with a quality product.

I went through the same thing with Green Mountain. I bought a barrel, it didn't work properly, I took measurements, called them and told them their product was out of spec, they said there was no way, and that I was wrong. I could have taken some off the trunion side of the barrel flange, it was better to make GM aware of the issue so they can correct it and in turn, put out better products. I sent it back, they confirmed it was out of spec, and sent me a new one that was in spec.

 

[root]

Let us know how the return goes and if they give you any flack on it.

For 300 it should look like a gem and work as advertised.
Not be like what you are showcasing right from the get go.

If I ever find a FA bolt cheap I'd like to try a conversion just to say I did it.

Rich

 

[root]

PM sent to you funner for a semi bolt ready to go at 1/2 the price you paid.
And it's a company that won't screw ya. I've delt with them before.

Rich

 

[Funner]

Thank You Sir

 

[wanneroo]

It's been a few months since I looked at it, but my bolt in my 2014 semi auto Vector is swirl mark city. All the swirl marks on the bolt I just thought was the norm or whatever, so in the next few weeks I should pull it out and have a closer look at it. It's never been a super reliable gun, if you take it out shooting for the afternoon you can pretty much accept it will choke at least once. Because of that it's kinda of put me off turning it into an SBR and wasting more money on it. Sometime when I want to spend the time and money to tinker with it, perhaps I will find another bolt and see how that goes.

 

[sousa]

My Norinco bolt looks a lot like that and it runs great.