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1/26/2009 4:40:58 PM EDT
How important is it that the pin that holds the gas piston onto the carrier be welded?  I saw a Interarms Tantal and the you could see the pin and push it back and forth with the tip of a bullet.  Will it fall out or cause other problems?  All the other ones that I have seen (ORF builds, etc) have a welded in pin.

Also, can you switch out the bolt carrier without affecting head space if you keep using the same bolt?
1/26/2009 4:52:32 PM EDT
[#1]
Most of them are not welded, but use a rivet instead. Many people actually have used a regular household nail that they flatten out with a ball peen hammer, then smooth out with a file or dremel tool...Its mainly there to keep the piston from unscrewing....you dont need a hardened rivet or a weld or anything fancy at all..
1/26/2009 4:56:01 PM EDT
[#2]
Kind of what I figured.  This was a roll pin.  I was just concerned that it would move so far to the side that it would scrape the gas tube and hang up the carrier.
1/26/2009 5:23:03 PM EDT
[#3]
One day at the range last year, my Century built Yugo underfolder's bolt carrier stuck to the rear after shooting about 8 mags in rapid succession. At first I kept pulling back on the charging handle and tried letting it fly, but it would not budge. I inspected the chamber, then unloaded the rifle for further observation.

Long story short, I took the top cover off to check the internals, maybe the FCG came apart somewhere and locked it up. After fiddling with it I finally noticed that the "rivet" that was in the carrier to hold the gas piston in place had walked out of its hole towards the left and was hitting the rear sight block as the piston/carrier traveled back forward.

I took the rifle home and punched the piece of metal out and to be honest it looked like a nail and not a rivet but either way it was not put in there very well at all. I can't imagine that was done in a Yugo arsenal and figured that Century did it although there are absolutely no US markings on my piston and by the wear on the face of it, I would guess it to be an original part so I don't know why they'd be messing with it.

In any case, I ordered a new rivet from Red Star Arms, hammered it in which didn't take much force at all and then peened over both sides and filed down each end to smooth it down somewhat to where it is essentially flush. I was kind of annoyed that the rivet was still "loose" and did not require much force to go into the hole but I peened it down pretty good so there should be no more problems.

Since then ammo has risen in price so I don't do the smoldering handguards routine much anymore so I have not really tested it out yet. In any case, it is important that the rivet/pin be in there good so you don't end up like I did although it doesn't have to be welded.
1/26/2009 5:35:14 PM EDT
[#4]
Thanks.  By "peen" the pin I assume you mean that you smashed each end flat so that it can't walk out?
1/27/2009 12:23:40 AM EDT
[#5]
Yes, I tried smashing down each end as best I could, then filing it flush as possible.
1/27/2009 1:40:42 PM EDT
[#6]
The pin isn't REALLY needed. The gun will run without it as long as the piston is screwed in.

My buddy  bought 4 wasr's. Every damn one of them DIDNT HAVE A PIN IN THE PISTON! They were just screwed in by hand, he's put 2K through one of them so far, no problems AT ALL.
1/28/2009 12:04:08 AM EDT
[#7]
I just received a WASR 10/63 from Henderson Defense and there is no pin in the piston/carrier but rather what looks like a weld that has been sanded down and painted over. On the other side you can see straight through to the threads of the piston.
1/28/2009 4:57:56 AM EDT
[#8]
Quoted:
(...) Many people actually have used a regular household nail that they flatten out with a ball peen hammer, then smooth out with a file or dremel tool (...)


I've heard this repeated a lot, but I've yet to see it. Does anyone have a photo of a carrier / piston that they assembled with a nail?

By the way - the rivet should *not* be a drive fit into the piston / carrier hole. It should fit with easy clearance -  see the DIY gas piston installation resource (top of the forum) for more info.

Also - Century gas pistons are not marked U.S. - but the Tapco and AK-builder parts are.

-L

1/28/2009 6:51:09 AM EDT
[#9]
Quoted:

I've heard this repeated a lot, but I've yet to see it. Does anyone have a photo of a carrier / piston that they assembled with a nail?

-L




Ill get some pics for ya..Ive done all of my builds with a nail, and so far never had a problem on any of them.
1/28/2009 5:38:48 PM EDT
[#10]
I do not believe the gas piston should be welded on.  The pistons are supposed to have a little bit of play in them.  The correct Soviet method is to rivet them.  A correct riveting of the gas piston will not allow you to push the rivet back and forth with a bullet tip
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