hello gents, lurker here for a while and this is my first real post...

I have a ar15 rifle already, and starting a carbine build for my 14 yr old son and i need some advice..

my first rifle is a oly ( i kno i kno) that i have put together thru the last couple yrs. it consists of an oly upper and lower that I have added a oly 20" stainless ultra match barrel,
machined and threaded the barrel and added a dmps lavange compenstor, double star gas block, jp interprises modular free float handguard, true faced the receiver at the barrel
mounting flange, luth-ar mod1 modular stock, dmps panther hand grip, reworked factory trigger down to just over 4 pounds pull, tactical charging handle, and a 4-16x50 mueller
tact scope.

as you can imagine it's not a light gun so my son wants to build a carbine and i have started gathering parts for it. I have a new bcm bcm4 upper, and looking at either areo, mega or sikkens lower to go with it and other odds and inns to go with it. now i use the first rifle for target and this carbine is going to be for plinking so my question is do you think i
would be better off the swap out the lower and upper with the target ar and use the oly upper and lower for the plinker or do you think at this point it really matters?

now to be honest i haven't sat down and got to paper the target ar with high quality ammo or handloads yet so I really can't say to its accuracy. most of my projects and done it the
late hours of the night as Im a single dad raising 3 kids on my own so my daylight hours are pretty much taken up so the shooting range is usually put off LOL.

another question on installing barrel nut, i have heard just clean threads really good and assemble, clean threads and install with blue loc-tite and last but not least, clean threads
and install nut with anti-seize..... soooo which is the best method?

thanks guys and I have learned alot from lurking here and appreciate any input...

Bill

NO loc-tite on barrel nut.  Grease.  Just build your sons rifle from new parts.  I have built with several Aero Precision lowers and they are nice and very affordable...$55 for blems.

First of all kudos to you for being a good father and being involved with your children! That's something this country needs a lot more of. Now for the rifles. I don't think there is anything to gain by swapping receivers unless the olys are bad out of spec which you would probably know by now. For the barrel nut the spec is Aeroshell 33ms but any EP moly grease will work. Do not use loc-tite or anti seize.

man I type too slow on this phone.

This is what I got for installing barrels. You don't need to use a lot so it should last a bit.

I do not use loctite on a single thing on my rifles.  Never have, never will.  If you do it properly, you don't need it.

This

put this on the barrel extension and UR before insertion:

https://www.ucwrg.com/materiel/miscellaneous-components/18/aeroshell-33ms-grease/

And if you are using a standard barrel nut on a stripped barrel (gas block not installed yet) then do yourself
a favor and get a PRI barrel wrench
http://www.midwayusa.com/product/123930/pri-barrel-nut-wrench-ar-15?cm_vc=cross_sell

You don't need loc-tite because the gas tube prevents the barrel nut from turning. The AR fits together like a puzzle, one thing holds another.

I don't really think there's much point in swapping out the receivers to build the plinker with unless you're going to plan on doing a really custom lower with a match trigger. You could just build another lower with the quality trigger and not worry about the upper at all and simply build an upper for the carbine snapping it onto the Oly lower. The only thing that might make a difference there is if you have a rifle stock on it but that's easy enough to change.

DON'T use loc-tite on the barrel nut! A thin coat of any moly grease or even wheel bearing grease will do just fine for an anti-sieze and that's all you want to prevent just in case you ever decide to remove the barrel.

Some folks put just a tiny dab of loc-tite on set screws for a gas block or for a hand guard, I never have. I've never had a problem with any of them either.

Thanks guys !
 I will leave the oly alone and finish the carbine build on its own parts then, found a seekins sp15 lower I will pick up in a week or so.

Also NO loc-tite on barrel nut !

again thanks for the replies and knowlegde.

Bill

I use blue Loctite on stuff I might be taking loose........Red on stuff I want to stay put........I use anti-seize on the barrel nut to receiver........Ive used this on bolt action rifles as well........and never had an issue since 1989 when I assembled my first AR..........