I got 3 full mags through it, on the 4th, nothing. Hammer is stuck back. It switches to semi ok but won't switch back to 2 shot or full. I take it apart, nothing appears to be broken. I am finally able to get the hammer to drop and a small piece of metal falls to the bench. Turns out, the little spring thing that holds the arm on the selector fell off and wedged the hammer in place.

I manually cycled the trigger group and it looks ok, but the little flat spring will not stay on the selector lever.

So, not sure how to fix this as parts pretty much do not exist. I could stake the pin to hold it on, or maybe put a dab of weld on it with the TIG rig. Any recommendations?

Jason

Picture G, number 4 and 3 show the part

Part #3 is not  pinned or in any way captive to the selector body and is designed to just slide on and off the selector barrel body.  This is one of the things on an AC you have to be careful about when disassembling or reassembling the gun as that little piece (#3) can and will just fall out once the trigger group is removed from the receiver.

What holds Part #3 "Link Positioner" in place is #4 "Selector Arm". If it is all assembled properly the nub/rivet part on #3 fits into the groove on part #4 and when the trigger group is installed the slot on #4 prevent #3 from coming off the selector barrel.

When you install the trigger group back onto the receiver and stock you have to have the selector set to semi-auto and part #4 has to slide onto part #3 as you slide the receiver and trigger group together into the stock.

My guess is either part #3 (link positioner) is damaged and the little rivet head on the bottom is missing or loose and/or somebody previously reassembled the gun incorrectly and didnt get the #3 rivet head on the Link Positioner lined up properly with the slot in the #4 Selector Arm and it then fell out jamming up the gun.

If nothing is damaged and its assembled correctly it will all stay together and work.

Hope this helps


Attached File

I read up on the disassembly procedure. The issue is the little arm is made of 2 pieces, the arm itself and a flat piece of steel, probably spring steel to keep tension on the arm so the part doesn't slide off, I'll have to post a picture.

My personal gun and the very few I have ever worked on the arm is a single piece of spring steel with a single rivet piece through it.  Looks just like this one here circled in red.

Are you saying the Rivet has come loose from the piece of spring steel or you have a 3rd part?

Attached File

Try this

You should be able to see it now at the link.

Jason

It is set to private

Take 2, it should work now.

This is interesting as I have never seen an AC556 Link Positioner like yours before where it is made out of three pieces (two sheet metal and one stud)

However, I did look around online and came across another one posted similar to yours and can understand how it functions where the back piece of spring steel slides over the end of the selector barrel (as the other U cutout piece goes into the grooves in the selector barrel) and that back piece then retains the link positioner to the selector barrel as the back piece with the full circle clips/snaps over the end of the selector barrel.

The construction of the three piece units appears different with the stud part that appears almost welded to the two pieces of sheet metal.

I pulled my gun from the safe and mine is made with a single piece of sheet metal and the stud is like a rivet with a pronounced head on the other side.  While you don't have a picture of the backside of your Link Positioner the other one online you can see its appears to be relatively smooth and the back side is all black.  Mine in contrast has a very pronounced silver rivet head on the backside of the sheet metal piece.

Attached File


Yours on the left and images of the one I found online on the right.

This is mine below.


Attached File


My only guess is that maybe Ruger updated this part from a three piece construction to a two piece construction as the back part would break off over time and jam the gun (like what happened to you) and that back retaining piece is not really needed as once the gun is assembled the link positioner can't come off the selector barrel as its captive via the selector arm itself.

In terms of a fix, unless there is something else wrong with your Link Positioner and the stud isn't securely attached to the sheet metal with the U cutout, I would probably just use it "as is" like the two piece construction units are used in a non-retained fashion.  I would be concerned about doing more damage welding or trying to stake on such a small thin part to add back a piece that isn't really needed vs. just using it as is.

You could maybe call David Spiwak and see what he suggests as well.

Good luck with whatever you decide.

Thanks. It sounds like it's not even needed. I think I will contact the guy above to see what he says. I inherited this rifle when my father passed away, so I'm not in any hurry to shoot the barrel out of it, in fact I have 2 other MGs to shoot if I want to.

It seems much more fragile than my M16, but I do like the way it shoots. Pretty sure I'm going to keep it. It's the full stock version.

If it turns out you do need to replace the part. Contact David Spiwak.  He may be able to help you.

He can not. He offered no advice other than those two parts should be connected. I have a plan, I'll see if I can make it work. It's just a machined part and I have a sample, material analyzer, and a Bridgeport.

@macloud Is it a 190 or 191 series AC-556?  The earliest 190 series guns were different from all the later guns.

191. I actually had a small center punch and was able to stake the spring down. Looking at how it goes together, I'm not sure if it really makes a difference. I tried to pry it back off, and it seems to be on there pretty good.

Talking with some guys at work, these stamped parts would be fairly easy to replicate for spares.