Upper questions

[Mule]

A friend loaned me an upper till I buy one.
It has a C w/ a couple spaces and then a MP where the p is part of the m then followed by Chrome Bore. This is just behind the muzzle brake.
I have never had an AR, or even shot one. I have done some reading up on them before I started building this one, so I have at least an educated clue...... :P

Questions;
It's missing the gas tube, bolt and charging handle. I ordered the bolt, charging handle today and a standard long handguard, but not the gas tube.
How do I make sure I get the correct gas tube? From what I figure it's a 20" barrel. I un screwed the nut and removed the barrel by hand, measured from the back to just behing the muzzle brake.

2nd, the pivot pin is smaller than the hole in the upper. It has almost a 1/16" gap in it when I pull the upper and lower apart. Should I try and make a shim to go in the upper hole to get rid of the slop? This is an OLD upper.

Any help would be appreciated.
Thanks

[Bumblebee Bob]

Nice buddy. He need anymore friends?

Gas tubes come in two lengths, well three now that 18" mid-length have caught on, 16" carbine and 20" rifle length. Order a standard 20" and you'll be in like Flynn.

The pivot pin hole in the upper is larger than the pivot pin in the lower, correct?

If so you need this (http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=19965&title=PIVOT-PIN+ADAPTER+BUSHING).

Brownell's will have the gas tube you need too.

[Mule]

Yeah, he's a pretty cool guy. He has some pretty cool toys in his vault that I can shoot most any time. It also helps that he trusts me...

Thanks for the help. I bought a start to finish build book, so hopefully I won't have to ask a bunch more questions.....
thanks for the info.
G

[Mule]

Hummm,
I do have more questions.

This upper is an old Colt that was on an M-16. I was told the front handguard cap is a thin type that is hard to find. Is this true?
Numrich doesn't show Colt M-16 parts, so who can I get it from?
Greg

[Marlin]

Bushmaster, Maybe. Or, There is that one guy at Tanner, Sets up on the south side of the bathrooms. worse comes to worse there is always EE over at ARFCOM.

[Great-Kazoo]

i have a round handguard cap off a colt 20" pencil bbl. lmk

depending on how you set the upper up. you could maintain a stock handguard look or go to a freefloat tube. your choice

[Mule]

I PMd you. Thanks

I got the story on this upper.
The guy my friend got it from was a Nam vet. When he got out of the service, the armorer changed it to semi auto. He had two uppers for it, one w/o forward assist and this one. My friend got it from the guy when he was gettig ready to go to jail. He was becoming pretty un-stable mentally and knew it. Sad story....

[The1andOnlyKC]

I have an extra Handguard cap for round handguard that might work for you.

let me know if you need it.

[Mule]

All things have worked out!!!!!

It's together thanks to Jim's help. He ended up supplying me with the spring and showing me the finer points of assembly. Good taste in music too, Tom Waits and Van Morrison.....
PS, the triangular one I had ordered earlier ended up fitting the guard and barrel perfectly.

thanks for all the help and info

Greg

[Great-Kazoo]

now go and road test it. that 1/12 bbl will really like the 55gr
thanks for stopping by. to bad we couldn't coordinate our time a little better

[Mule]

No worries, thanks for your time.
I would liked to have spend some more time talking about this stuff.
It would have been interesting to have machined on that stock some too. I'm going to get one of those mills I talked about and try it. I have some of the HSS end mills that I could stick in my drill press, but don't have the X-Y table for it.
On a side note, I forgot to ask you about the upper. I'm assuming it's a 5.56 model since it's an old Colt.
Greg