Well, I narrowed it down to a PSA. I I went ahead and ordered a stripped lower, and an MOE lower build kit. For the upper, it has come down to either the, PSA 16" M4 upper (normal weight), or thePSA 16" Mid-length, light profile, MP upper. PSA uppers

I ask this because I assume the lighter version will be best, but I am not sure the difference between the "M4 upper", and the "mid-length light profile MP upper".
The latter is more expensive, but only by $20.

I will be using this rifle for home defense/SHTF, target shooting, and posibly some traing courses in the future. It would be nice to have a light weight barrel vs the heavier barrel because this will primarily be for CQB.

I know, it's another noob question. But your advice is greatly appreciated.

Thanks in advance guys!

smitty

"M4 upper"  uses a carbine length gas system and has barrel cut-out for the M203

 "mid-length light profile MP upper" uses the longer mid-length gas system and doesn't have the cut out for the M203



 

Is that a desirable feature?

The cut-out is basically for looks only, as you are not likely to attach a grenade launcher to your rifle.

The mid-length gas system is pretty popular right now for 16in barrels. it will cause the action to cycle a little slower, minimizing wear and tear.

You want the mid-length lightweight...thank me later



The only other option I'd recommend is the 14.7" lightweight, my brother has one and it's pretty sweet handling

These guys are on the money about gas tube lengths...M4 is a carbine length tube (7") and midlength is a midlength gas tube (9").  There is also a rifle length gas tube that is 12".  From what I understand, the middy will give you a longer sight radius and more room for your hand and do-dads.  It only make sense b/c of the extra 2".  A middy will also have milder recoil and will cycle better, but I can't tell you if this is true b/c I've never shot a M4.  

As for barrel profile, the light weight barrel is just lighter making it easier to maneuver.  I have to believe that a light weight barrel will heat up faster under rapid fire b/c of less material.  That may reduce barrel life.  It may not be as strong due to less cross sectional area.  But really barrels are pretty strong!  I just read this so I can't act like I'm a super scientist.  You need to figure out what you're going to do with your rifle.  It sounds like you want a rifle for HD, but I'm sure you'll enjoy going to the range and burning through a couple hundred round a trip.  Check out the FAQ section in GD, item #1.  Good luck in your decision.  And welcome to the club!

http://www.ar15.com/forums/t_3_118/492084_AR15_Discussions__FAQ.html

http://www.ar15barrels.com/profiles.shtml

I have shot carbine, mid, and rifle length gas system AR-15's, and honestly the only time I notice softer recoil is when using the rifle length systems. The difference between carbine and mid, in my experiences, have not been that different in the felt recoil.

The M4 cut being desirable is something you have to decide. It really isn't needed unless you will be buying a M203 grenade launcher, so just pick whichever you think looks best.

I think light weight is great for carrying where a lot of rounds will not be fired, like hunting and HD.
Also target shooting where the time between shots can be spread out.
Personally for SHTF or training courses that emphasize range work I would go with a M4 profile at the least and I would seriously consider a heavier profile.

Get the mid-length for the 16" barrel.
A 16" is more in proportion as a middy and the weight difference between these two will be negligible.

I would go with the 16" LW Mid-length, but beware, PSA's LW barrels are closer to a medium weight barrel(not a pencil barrel). Short of you using the M203 cut-outs on the carbine-length gas-system M4 profile barrel, there are only going to be positives with going mid-length. Softer operation(which you may or may not notice), longer sight-radius and more hand-guard real-estate. All wins in my book.

If you are going to look for accuracy, I'd go with the satinless barreled upper the have. Might weigh a tad bit more, but great accuracy and wider range of ammo that you can shoot. The 1/7 twists cannot shoot the lighter weight bullets. The impart too much spin on the bullet causing them to disintigrate. If you only are going to shoot heavier rounds, the its isnt such an issue.

Best learn the truth before you post. A 1/7 will shoot light bullets just fine. I shoot down to 40gr out of mine. How much lower do you want to go?



Stop spreading internet BS mis-information.



 

Thanks a lot guys for the advice. I am going with the Mid-length light weight 16" upper. I feel the lighter weight will make more sense in the situations I will be using it in. I can always buy the M4 style barrel for my next build ;).  (getting ahead of myself!)

Again, thanks.

Good choice, rest assured you chose well.

I guess you should tell Patrick Sweeney that he is spreading internet BS mis information, because that is where I got it from. In print, not on the internet. But what does he know......

+1+1  both the 1:7's I shoot do just fine down to 40gr possibly lower... But why

Go with the middy my son