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9/22/2017 12:11:25 AM
Posted: 8/2/2003 7:26:25 PM EDT
I need to swap out my A2 upper for a Flat top, is their anyone in the area who can help me?

Thanks, Brad from Lakewood
Link Posted: 8/2/2003 7:33:14 PM EDT
Ah ... you just push out the two "take down" pins and carry on.

There has to be more to your question than that right? Like you want to pull the barrel and use it on a second upper you're buying right?
Link Posted: 8/2/2003 8:14:17 PM EDT
Link Posted: 8/3/2003 7:00:06 AM EDT
I see.

To swap uppers you'll need a 1/8" pin punch, a barrel nut socket wrench ($15 from Armalite/Bushmaster/Cheaper Than Dirt, etc.) and a 1/2 socket wrench (a torque wrench is better - Harbor Freight $20).

Take the upper off the lower - remove the bolt, bolt carrier, and charging handle.

Remove the handguards, remove the gas tube pin by knocking it out of the front sight tower with the pin punch, push the tube into the upper receiver until it comes out of the front sight tower then remove it.

Insert the barrel nut socket's "teeth" into the little "spoke holes" of the barrel nut and loosen by inserting the 1/2 socket wrench into the matching hole in the barrel nut socket.

A bit of molly grease on the threads of the new upper helps - I've used clp in the past and it's worked. Thread the old barrel onto the new upper using your fingers. Put the barrel wrench onto the barrel nut and tighten - if using a torque wrench you want at least 30# but not more than 80# - the idea is to line up the spokes in the barrel nut so that the gas tube can fit back into the receiver. 30# is a lot of torque. If one hole doesn't align work towards the next one tighter.

Slide the gas tube back into the reciever, back into the sight tower making sure that the hole faces downwards and the retaining pin holes are sideways. Tap the pin into the hole, replace the handguards and shoot.

Not bad from memory eh?

I suppose a gunsmith might take 10-15 minutes to do this and charge you too much to do it while scratching your barrel and upper up doing it.
Link Posted: 8/4/2003 9:20:34 PM EDT
Brad, I have all the necessary tools and I'll swap out your upper no charge. I'm in Lakewood too. Check your IM.
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