I just completed my custom AR15 and im having issues.
ISSUES:
1.Magazine does not drop freely
2.The bullets are getting mared when I hand cycle them through
3.Ocassinaly the bullet some how will get pushed back into the casing
4.While hand cycleing rouds through, there will be stoppages I.e. mostly double feeds
5.When I charge the rifle to eject a chambered round the bolt seems to slightly lock up


I would like to note I contacted Rainier Arms reguarding the upper recievers right hand feed ramps left hand corner ever so slighty protruding into the barrels feed ramp.  I was told this should not be a problem however if it is to send it in so they can look at it.
RIFLE PARTS:
-North Tech Defense Upper and Lower Reciever
-RA Select Series 14.5 inch barrel w/ lantac dragon muzzel brake
-RA match grade gas block and gas tube
Im using a V7 weapon Systems buffer tube with a JP SCS 15 aswell as the V7 QD end plate and castle nut.  I had to back the buffer tube off about 2 threads so I could get the take down detent and spring installed (wich was a son of a bitch). luckily you dont need the buffer retainer and spring when using the JP SCS15 or I would have been screwed.  Why I had to back the buffer tube off is because the protruded QD section would contact the rear of the lower reciever and push the end plate into the buffer tubes threads causing the end plate to lock up IS THIS CAUSING SOME OR ALL OF MY ISSUES?

Other than the listed above the rifle seems to function fine!  I HAVENT EVEN FIRED THIS RIFLE YET

 

True, however what about the bullet getting marred up and pushed back into the casing?

All replys focused towards problem solving will be highly appreciated.

Could be a product of hand cycling or that you are over analyzing the situation.

I'd venture to say a round being shoved into a chamber might get some marring .... how bad is what matters.

Mag issue --- try new mag, not just a different one, but a new one.

Projectile being pushed back --- try different make or lot of ammo


Shoot the damn thing, but start out with a single round and work up to a full mag if you are not sure of the rifle.

FWIW - On a bolt action rifle I manually cycled through 10 round, everyone of them was marred in some way from the experience however the rifle performed flawlessly at the range and in the field.

Hope some of this is helpful.

Thank you ill be testing it out the weekend.  Ill be loading one bullet in at a time to break the barrel in any ways again thank you.

Plz...any helping comments are much appreciated.

Any one want to weigh in?

Pics would help out.  There are couple of possible solutions or comments.

there's your problem go shoot it



most of the problems are from not fast enough bolt movemnet



 

go shoot it and stop wasting our time



 

You are over thinking most everything.

Shoot it !

With a brand new gun don't get too excited if has a glitch or three in the first couple of hundred rounds .

After about 300 rounds or so clean it and re lube and get back to us if there are any problems .


It kind of makes me nervous when I hear some guy who hasn't taken a particular firearm to the range talk about hand cycling ammo through it.
Are they just sitting in their living room massing about with live ammo? Yikes !

1. Stop hand cycling.
2. Shoot the shit out of it.

I'm not sure why people feel the need to try and hand cycle ammunition in there firearms???

You lucked into a bitter crowd, but they aren't wrong, these questions get asked a LOT, and AR Basics is where they should probably be.
Mags don't drop free, could be the mag, the well, or the release. What brand and type mag are you using? What is it dragging on?
Hand cycling is good, to a point, you determined everything moves, that is the extent of its usefulness.
You can expect pretty much any mag fed firearm to "mar" ammo as it feeds, the extent varies from light scratches to heavy gouges and bent projectiles. If it is just scratches not deep enough to hang a fingernail in it is not worth worrying over, same for a slight deformation of the meplat or tip of the bullet, those can be considered normal though not ideal.
Bullet set-back is not good but not entirely abnormal, depending on severity it may only be detrimental to accuracy, it could very well be due to the ammo. What ammo is it? If you cycle the same round repeatedly you can pretty well bank on getting some set-back.
Not entirely sure what you mean by lock up while ejecting, but the action parts will not move smoothly on a erector set gun or even factory assembled until they have worn into each other. This may take 10 rounds or it may take 1000. My 5000 round carbine is silky smooth when hand cycled, my 200 round rifle feels like the BCG is grinding marbles, both cycle fine when live fired.

Without knowing the severity of each of your issues I can't say if they are really problems. What I can say is live fire will tell you for everything but the mags not dropping free. I can also say every single one of them could be caused by the magazine.

Shoot it

This man know what he speaks. When hand cycling bullet pushback and marring is quite common. OP, you need to make time and go fire your new bang stick!

While i agree OP needs to go out and try the weapon, let us not forget two important things:

Bullet setback can cause a kaboom and explode the weapon and shouldnt happen hand cycling. It should be investigated as why that happened.

A proper and complete function check of any weapon should be performed before attempting a live fire.

Double feeds are usually mag related as far as bullets being pushed back into the case ....hand cycling is not the same as the rifle cycling while its running....not shot yet then go shoot it and see if it has a problem first then if it does well pick things apart.

I had one marring rounds really bad. Turns out that the feed ramps were not lining up properly. This was a brand new store bought upper. I wasn't happy with it, so I sent it back. Take a look and see if this might be an issue. If it's twisted bad enough, it could also cause bullet set back because it's not feeding smoothly. May or may not be, but it happened to me.

This...^^^.  And shoot the damn thing.

Its also not the best idea to hand cycle live ammo.

+1 to both of these...go buy some dummy rounds to hand cycle I have two that i use to test extraction but i agree with all these other guys the only way to know what you are going to get when you shoot it is by....shooting it.

OP:  Shoot the rifle, keep track of problems while shooting, total round count, and any problematic rounds.  Also, provide pics of marred rounds, and provide pics of rounds with the bullet pushed into the casing.  Also provide specs of ammo. Provide pics of feed ramp and BCG broken down.

This helps people troubleshoot your problems.

Oh, and the first time you shoot it, you might want to hold it away from your face for the first couple of rounds while pointed in a safe direction.

I do all of mine, whether a custom build or a production rifle/handgun.

Prof not everyone should have access to firearms.

Common sense should dictate to fire the damn thing before crying on the internet about something.

Pic of your feed ramps would help

Seriously, you shouldn't be hand cycling live rounds - you'll eventually deaden the primers as the firing pin contacts the primer ever so lightly each and every time.  If you do hand cycle live rounds, either do it from an open bolt and drop it on a mag, or pull it back with some authority and just let go.  Don't ride the charging handle or impede it's forward progress at all.  The bullet setback and scraping was caused by your repeated hand cycling.  I repeat - do not practice hand cycling rounds.  Go buy some dummy rounds or make them.  If you can chamber one round, more than likely it will fire and strip the next round off the top of the magazine.  You're thinking too deeply into it.  The AR is not a handgun and you sound like someone coming from a handgun background.  As others have stated: take it to the range and if you're still having problems, take it to a gunsmith.  

Without a magazine inserted, pull your charging handle back and forth at varying speeds - do you hear anything other than metal smoothly gliding over metal?  If you hear a "zipping" sound, it means that you have material, probably from the BCG staking job that's causing friction with the inside of your upper.  Look for protrusions on your gas key and if any look abnormal, gently file them off with a small hand file.  Go slow and be careful.  I had this happen once with a new build.  I had gotten a little over-zealous when staking a BCG and there was just a bit too much material coming from the sides of the gas key that it was binding in the upper and causing symptoms very similar to what you describe.  It will correct itself over time if you just shoot it, but in my opinion, material is sticking out,  and it needs to be removed.  Hope that helps!

no it wont/he's hand cycling which is causing his problems
 

My point is I paid over $2,500.00 for the base rifle.  I certainly dont want it to blow up.

At over 2500 I would of gone right to the range and shot it.  At that price it had better be turn key!!!
It should have been test fired already by manufacturer to ensure proper cycling.  Hell even my 575.00 upper was fired to check functionality before it was shipped out to me.

Who put it together?????

My self  I bought all the individual parts.  I did months of reaserch on all of the parts selected to ensure quality came first.  The only things I didn't do is assemble the base barrel, pin the gas block or pin and weld the muzzel brake.  All else I did following Mil Spec procedures with the help of AR15.COM of course  I even bought the detents and springs from Damage USA the nickle teflon kit.  Also Im using a Wilson Combat TR TTU, BTW its so crisp and has a very short positive reset

It's not going to blow up.

All those "fancy" parts don't mean jack if you don't know how to put a rifle together properly, and they CERTAINLY don't matter if you never fire the damn thing in the first place.

You've gotten some great advice. You should really consider following it since you came here asking for help.

Absofuckinglutely.  There has been a ton of overthinking lately, around here.

I would like to see pictures of all this carnage, and the M4 ramps on the barrel.  I have a RA Select barrel, and it is perfect.

At least put 1 round in a mag, seat mag in the lower with the bolt locked back, hit the bolt catch chambering the round, and fire the rifle.  I am betting there will be no destruction.

Again, post pics of all of this you have mentioned.

I'm sure your rifle is fine.  Go shoot it...and stop hand cycling it. Let us know how it goes!

I have a RA select barrel on a build. Like posted above this, the feed ramps are perfect. Like they were made while the barrel was installed. But that's with a Seekins upper.

I'd clean it, to include using a chamber brush, and shooting it. One handed with it way out in front of you if needed, but don't be surprised if stuff that's brand new is tight.

The RA Select barrel chambers might be a little tight, possibly. So if you use junk ammo, you may have extra issues.

Use quality ammo to break it in.

I got the rifle out to shoot.  There were several problems at first.  After about two mags it ran much better.  Now it rarely has a hickup and if there will be problems in the future......time will tell.   Thanks for all the help guys

If you beleived youve built it correctly then just go an shoot it....if not have a gunsmith check it and never build again...just some advive hand cycling a firearm doesnt duplicate that action when its fired.