barrel pin

[tujungatoes]

UXO2

Another method would be to open up the slot un your upper that the pin fits into just enough to allow it to pass. Keep in mind this may preclude the use of other barrels in that upper later on. If it's a specialty/unique upper then I certainly don't recommend this option. However if it's just something you picked up to put this rifle together and you don't see yourself changing it out this might be an easier way to go. It all depends on whether you think you may want to tear it apart later.

tujungatoes:



I guess I will just recycle your comments as it seem I will be using it alot when you post.

OP posted he could not even get the pin in that is was oversized for the hole and I never said he needed to set the pin all the way in. The pin is not tapered so once it fits into the hole entrance snug it should go be able to be tapped in all the way, so no extraction would be needed.

The technique I posted is used by many gunsmiths for small pins that are either to small or take to much time to setup in a lathe to size down. This of course is normally done in a drill press but I can not assume OP has access to one and hand drill is just as good. Using a flat object around a stationary round object will never produce a rounded object. That is why you rotate the round object and keep the flat object stationary on it. I suggested the use of fine sandpaper because unless you are experienced a file will take off material at a faster rate.

The only ghetto technique here is hand filing around a pin and expecting it to stay round.

You can continue to flame me and try to make me look clueless like you have in some other posts. The facts are the facts and you maybe should read all the posts start to finish before posting something to try to make someone else look bad.

I know you want to bring up the whole Saiga rifle post but go here if you actually want answers and not just flame others.

If you don't that is fine but I am no longer gonna let personal attacks against me to try to discredit me get a pass any longer.

To the rest sorry about this temp hijack but I had to take a stand on this. This is getting out of hand with the arm chair gunsmiths who think they can make a professional look stupid, then go around yelling "WHO DA MAN".

Dan...I'm cool with you not agreeing with my method. there are a few different ways to skin this cat.

However I do take exception to your arrogant, ignorant, and condescending assessment of my fix for this problem. The only function that pin serves is to align the barrel in the upper. A flat spot on either side of the pin would have absolutely zero effect on the appearance or function of the rifle. In fact the only thing it would do is let the OP fine tune(to an extent) the clocking of his barrel in the upper and prevent it from twisting while torquing the barrel nut by getting a good tight fit between two flat surfaces. Also I AM the king of ghetto fab. I wasn't using the term "ghetto lathe" in a derogatory way. I'm sorry if you took offense. *edit* Also, I never flamed you here. Nor did I bring up the Saiga thread where you showed us all that you had NO IDEA what we were talking about. You brought that back up.

BTW I did read all the posts here...I'm pretty sure I have a decent grasp of what's going on here. Were that not the case, I wouldn't have opened my mouth to voice an opinion.

I'm not trying to make you look stupid Dan. You do that enough on your own....But since you decided to call me out and get personal let me point out something else. You really seem to enjoy looking sneeringly down your nose at us amateur(arm chair) gunsmiths. I DESPISE that....Do you know what the difference between amateur and professional is?...Professional just means you get paid. It does not imply any measure of skill or competence. Only that you get paid to do something. I'd be willing to bet large sums of money that there are more than a few "arm chair" gunsmiths around that have forgotten more about gunsmithing than you "Mr. Pro or I "Mr. ghetto fab" will ever know.

[ke6guj]

tujungatoes:



I guess I will just recycle your comments as it seem I will be using it alot when you post.

OP posted he could not even get the pin in that is was oversized for the hole and I never said he needed to set the pin all the way in. The pin is not tapered so once it fits into the hole entrance snug it should go be able to be tapped in all the way, so no extraction would be needed.

The technique I posted is used by many gunsmiths for small pins that are either to small or take to much time to setup in a lathe to size down. This of course is normally done in a drill press but I can not assume OP has access to one and hand drill is just as good. Using a flat object around a stationary round object will never produce a rounded object. That is why you rotate the round object and keep the flat object stationary on it. I suggested the use of fine sandpaper because unless you are experienced a file will take off material at a faster rate.

right, if you can put the pin in the drill, you can ghetto lathe it with sandpaper. But with a pressed in pin, he probably won't be able to get the pin out cleanly to put in the drill.

The only ghetto technique here is hand filing around a pin and expecting it to stay round.

there is no need for the in to stay round. it doesn't rotate in the barrel. filling the pin so that it has two flats that exactly fit into the receiver slot should be no issue.

if it were me, I'd determine which item was out of spec, and based on the OP trying the barrel in multiple uppers, chances are that it is the barrel pin that is overside vs. the slot being undersized. Byt filling on the pin, it brings it closer to spec vs. making the slot oversided and then loose for any other barrel.

[tujungatoes]

Can anyone explain how you pass a file passed the pin while it is installed and effect the width? There is the barrel shoulder to stop any file action.

With a small flat jewelers file you could use just the tip to file the sides of the pin. You wouldn't get a very long stroke, but seeing as how the ammount of material that needs to be removed is relatively small I immagine it wouldn't take too long.



I apologize for my use of a round file in the photo. It was the first one I could find. Not very "professional" on my part, but I figure you get the idea.

[BSlacker]

Byt filling on the pin, it brings it closer to spec vs. making the slot oversided and then loose for any other barrel.

Could you post a pic of a file passing the pin while in place. The barrel shoulder won't let you run a file passed a pin in place on the extension. A file must be moved passed a object to affect it. Just touching the pin won't affect the size.
Thanks for the input on the rat tail file but you have more time than I. I would end up scratching all around the pin and why. It is an easy fix if you want to know how I can PM you the answer.

[tujungatoes]

Could you post a pic of a file passing the pin while in place. The barrel shoulder won't let you run a file passed a pin in place on the extension. A file must be moved passed a object to affect it. Just touching the pin won't affect the size.

I posted a pic for you.

[TURBOELKY]

Could you post a pic of a file passing the pin while in place. The barrel shoulder won't let you run a file passed a pin in place on the extension. A file must be moved passed a object to affect it. Just touching the pin won't affect the size.
Thanks for the input on the rat tail file but you have more time than I. I would end up scratching all around the pin and why. It is an easy fix if you want to know how I can PM you the answer.

Idk, I'm positive I could remove metal with that file just like that, easy....

[BSlacker]

Idk, I'm positive I could remove metal with that file just like that, easy....

I don't think you do the barrel pin any favors by pecking away at it with a tiny rat tailed file. If the object for you is to remove a ragged amount of metal from some part of the pin then have at it. As for easy well maybe, but I think not. Filing that pin is not normal.
Nobody knows if the pin is good or bad and people want to file furiously with a tiny file. This will most certainly end up creating another problem even if it is just a hidden appearance issue with scratches from the fast and furious, filing. You will always see it in your mind that your build is not the greatest it could be. If you must do it in place then use a machinist scraper an equal amount on each side of the pin. This will do it in a couple of passes and look good when finished.
First find the problem. My guess is the OP is at work and when they get time will measure the slot first and then contact the barrel maker.
This is a problem that occurs from time to time and there is a standard fix. If you search AR15 forum you would find this info. Just send it back and the maker will do the fix and return it in no time.

[uxo2]

BSlaker.

The manufacturer finally got back to me..

He's going to exchange it...

Interesting stuff came out on this thread ..
thank you all