Receiver Locking cams

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KC651
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Receiver Locking cams

Post by KC651 »

Im in the process of building a semi kit and Im at the stage to install my upper and lower locking cams. I saw a video TNW posted on Youtube but they don't give any info about the proper fitting and bucking bar needed.

I was wanting to know if someone could shed some light on the proper process and tools needed. If you in fact have the needed tool(s) in order to properly install the cams that you'd be willing to rent out.

Thank you
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Re: Receiver Locking cams

Post by JBaum »

Are you talking about the cam piece that the top cover hinges on?
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Re: Receiver Locking cams

Post by KC651 »

The 2 cams I'm talking about are in the front of the receiver. They are riveted to the receiver itself.
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Re: Receiver Locking cams

Post by JBaum »

The front of the receiver - at the muzzle? The cam that holds the flash hider holding lever and barrel bushing in place? Those are pins with hollow ends. You'll need some help. Put a center punch straight up in a vise, hold the pin in the muzzle on top of the center punch, use another center punch from above to flare the ends. Tap with a hammer to flare the ends of the pin.
Is that what you mean?

Pictures weren't working on this board - that's been fixed now.
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KC651
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Re: Receiver Locking cams

Post by KC651 »

Sorry that's not what Im talking about.

Ive included a picture of the cams Im needing to rivet in place on my semi receiver.
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Re: Receiver Locking cams

Post by Wondering »

KC651,

You are using the correct terminology. Those two pieces are the bolt locking cams. I'm sure you know the following, but here is the explanation for someone reading this who might not know: The cams are like little ramps riveted into the very front of the receiver. They guide the bolt rollers so that the bolt head twists as it slides into home and locks into the barrel extension collar. On recoil, they assist the bolt head in "untwisting" so that the rollers are aligned straight with the receiver channels as it moves backwards.

TNW has a video showing the custom bucking "bar" they use to rivet in the cams. It's a cylindrical shape with cutouts that fits into the space. It's internally threaded and a bolt is run to a securing crossbar that fits behind, through the ejection port and the upper feed channel. Here is a YT link showing that:

https://www.youtube.com/watch?v=XnE8FeBEatE

I am not familiar with anyone's home built method of doing this. I bought a receiver kit from TNW many years ago. For some odd reason it arrived with the cams already riveted into place. All I had to do was trim the excess off the rivets so I never had to figure this one out.

I don't recall reading any threads on this topic back in the day. I do know that several members here (or former?) back in the day did build ups from bare TNW receivers. If you can find their old threads, you might try PM'ing one of them to ask what they did.
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Re: Receiver Locking cams

Post by KC651 »

Ive actually watched that particular video several times. Unfortunately they will not replicate the tool and resell it.

I was hoping someone might have made a similar tool they would be willing to rent out.
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