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View Full Version : First Trip with New AR. Having feeding issues


gizmo688
September 14, 2012, 04:04 PM
I've got a 22" varmint built up that I took out for the first time today. I was shooting an assortment of 55g FMJ (100 rounds total). It shoots on target, but tends to function more as a bolt action. It seems to be short stroking, as it ejects the spent brass, but does not load another round OR lock back when firing the last shot. I also noticed via manual manipulation that there are times where the bolt just rides over the top of the round in the magazine without feeding it into the barrel.

First question: A guy at the range told me my rifle (specifically the bolt) was under-lubed. Is this a primary cause of a failure to cycle?

Second question: What is up with the bolt just riding over the rounds in the mag? I tried with multiple brand new PMags.

Specs:
Palmetto upper & Lower
22" .223 WOA varmint barrel
Rock River 2 stage trigger
BCM bolt carrier group
Vltor Emod A5 buffer/stock Kit

Edit: I forgot people like pictures...
http://i668.photobucket.com/albums/vv47/gizmo688/2012-09-14_16-09-09_332.jpg

TheSILENTtype
September 14, 2012, 04:25 PM
this is a gun, best run WET WET.

Not shotgun wet, or a little wet..but wet wet. Lube that puppy good.

Have you done any 'spring work' with this?

Father Time
September 14, 2012, 04:32 PM
seems to be short stroking, as it ejects the spent brass, but does not load another round OR lock back when firing the last shot

Not a mag issue. It sounds like it is undergassed.

gizmo688
September 14, 2012, 04:37 PM
I just finished lubing the heck out of it with high temp bearing grease. Not sure what you mean by "spring work". I haven't messed with any factory springs, and I have spent a little time working in the charging handle/buffer, but not alot.

TheSILENTtype
September 14, 2012, 04:40 PM
ok. people messing with springs or messing them up when stripping / customizing usually results in a similar type of problem. so thats one issue narrowed down. how far are the casings ejecting?

gizmo688
September 14, 2012, 04:44 PM
~8 ft from 3 o'clock to 5 o'clock. All the brass looks good. No extractor tearing.

TheSILENTtype
September 14, 2012, 04:46 PM
There is always the slight chance your sight tower (gas block) is off center a bit from the barrel and not letting enough gas through to operate the gas system. Aside from shooting a new rifle and not cleaning the cosmoline off it - this is the next most common cause in a new rifle.

My guess - you have fired off several full magazine as fast as possible and then left one of these cheapo rounds in the chamber unfired a little long. Some ammo has a varnish on the outside to prevent it from rusting......... when you accidentally leave an unfired round in a hot chamber it melts the varnish off the round and deposits it on the inside of the chamber. It makes your chamber sticky - and - slows down the ejection cycle process. Normal cleaning with oil does not remove the varnish - you need to clean the chamber will a steel chamber brush and mineral spirits or paint thinner.

What are you shooting out've it?

TheSILENTtype
September 14, 2012, 04:47 PM
Edit : saw above for ammo.

Fact is your rifle has a 1:9 twist barrel and a recoil spring that is optiomized for the SS109 62gr tip ammo. That is a fact. The other fact - you are shooting 55gr old style 5.56mm ammo that was designed for a lighter spring and 1:12 twist barrel. This can be a problem for some new rifles.

2 -

' what is up with skipping over '

it will eject the spent shell but the bolt doesn't travel far back enough to pick up the next round and load it = SSing. As you suggested.

3 -

should have said this first, but in a forum surrounded by pros i kind of skipped it. however it still needs a break-in period before it will feed reliably. Break in periods vary, but I'd say about 500 rounds should suffice. After that, your gun should fire even the garbage. Until then, however, just keep it clean and well lubed.

Powderman
September 14, 2012, 04:51 PM
Sir, looking at the picture you provided, I might have the solution.

someone has mated a carbine buffer and tube with a rifle top end.

The result is the dreaded "carfle"--a combination rifle and carbine that doesn't do either job well.

To isolate the problem, switch out your buffer, tube and stock with a normal sized stock meant for the full sized rifle. I'm willing to bet that your problem will resolve itself.

Then--if this does work for you--if you want the best stock for your rifle as it is configured, I recommend the Magpul PRS stock.

So...let us know how it works out for you.

gizmo688
September 14, 2012, 04:53 PM
I'm hesitant to believe that the gas block isnt aligned correctly, but then again I'm new to this. The barrel had an indent for the gas block screw to fit into. It seemed pretty much right on.

Ammo - Remington 55g MC and American Eagle 55g FMJ. Both performed equally. These 100 rounds were the first ever shot out of the rifle, and I was doing 100yd target shooting after sighting it in. They were all slow methodical shots.

gizmo688
September 14, 2012, 04:56 PM
Barrel is 1:7

From what I'm reading, I just need to lube better and shoot heavier loads?

TheSILENTtype
September 14, 2012, 04:57 PM
honestly bro, i am combing research and opinions of a pal in the next window.

i personally would opt to focus on opinions by the guys more farmiliar with this firearm. my responses were courtesy of research from GlacierWolf, who builds these as match guns.

gizmo688
September 14, 2012, 05:03 PM
someone has mated a carbine buffer and tube with a rifle top end.

The result is the dreaded "carfle"--a combination rifle and carbine that doesn't do either job well.

Brownells site: "By using a longer receiver extension, A2 action spring, and heavier buffer, the A5 system is ideally suited for rifle length and mid-length gas systems"

Well someone is mistaken. Just not sure who it is lol

impalacustom
September 14, 2012, 10:04 PM
Powderman is dead on. That buffer is too heavy for whatever gas system that WOA is using. Put an H2 buffer in and you probably won't have any more problems. The reason they put a heavier buffer in the A5 extension is because they are using a rifle length spring and there is less tension at rest in the longer extension than there is with a carbine length spring in the carbine extension.

Other possibilities are bad gas rings, loose gas key, or partially blocked port. Being the carrier is a BCM, I'd highly doubt the key isn't done right or the gas rings are bad being new.

You don't have to have an AR sloppy wet to have one run good, that is complete crap.

Sport45
September 15, 2012, 07:24 AM
it ejects the spent brass, but does not load another round OR lock back when firing the last shot. I also noticed via manual manipulation that there are times where the bolt just rides over the top of the round in the magazine without feeding it into the barrel.



Is the magazine seated fully?

moxie
September 15, 2012, 08:44 AM
And, any AR should run 55gr. Might not be the most accurate in a given gun, but it should run 100%.

ky hunter
September 15, 2012, 09:28 AM
Nice looking rifle how do you like that trigger I bet it shoots good. I bet if you change buffer spring to H 2 use white lithium spray grease on the bolt & Carrier + slide rails on upper it will shoot anything you put in the mag.
Have fun be safe and keep us posted.;)

DPris
September 15, 2012, 11:37 AM
And I would not lube an AR with GREASE.
Use a standard OIL lube.
Denis

gizmo688
September 15, 2012, 12:04 PM
impalacustom - I've going to put a few rounds through sloppy wet. If it still fails, I'll try an h2. Thanks.

Sport45 - yes. The mag release is in the intended slot on the magazine.

Ky hunter - I'm hoping the trigger needs some breaking in. It feels a little rough at the point of firing. My only other rifles are a heavily used Marlin 60 and a Garand (obviously also heavily used), so I'm used to a well worn trigger system.

DPris - why's that? I feel like grease sticks to the components better than oil. I use it in my 1911(slide only) and Garand with no problems. I realize that also means carbon and grime stick better to, but I don't mind the tradeoff.

Edit: Impala - Just doing some research and my Vltor kit appears to have come with a 5.3 oz buffer. Are you saying I should try a 4.6 oz buffer?

TheSILENTtype
September 15, 2012, 12:08 PM
it may not NEED to be run 'sloppy' wet, i agree. However, running is sloppy wet should make it MORE proactive at any rate. It should also fire covered in sand, water, sawdust or any other disgusting forms of nonsense that are not ideal... give it a shot. I don't think at this point lube alone is going to help but hey, at least you get to shoot for a while haha

gizmo688
September 15, 2012, 03:12 PM
Looks like she only plays well when wet. Just put 30 rounds through. With the exception of the first 5, everything performed flawlessly. Heres a picture of a misfeed issue that only happened for 2 of the first 5. I'm guessing they were just a result of a newly cleaned and greased rifle.
http://i668.photobucket.com/albums/vv47/gizmo688/2012-09-15_13-33-26_908.jpg

DPris
September 15, 2012, 05:26 PM
The AR, unlike the Garand & others, was not intended to be used with grease.
Use oil, as I said.
Denis

Mobuck
September 15, 2012, 06:25 PM
OH, PALEASE GIVE US A BREAK!
The idea that a rifle upper won't funtion correctly on a carbine lower is absolutely bogus. I can swap any of 4 different barrel lengths onto either a carbine stocked lower or an A2 stocked lower and run 55-69 grain bulleted ammo as good as any.
I will assume this is/was a newly assembled upper??? If so, it should have been dripping to begin with and sputtering and smoking with every shot.
As for lube, I use CLP on the BCG, red wheel bearing grease on the cam pin&bearing surfaces of the BCG/bolt lugs, and Remlube on the trigger/hammer pins.

DPris
September 15, 2012, 08:07 PM
And, you ARE keeping your chamber dry, right?
Denis

gizmo688
September 15, 2012, 08:19 PM
And, you ARE keeping your chamber dry, right? Denis

As in, am I greasing the chamber? Heck no.

TheSILENTtype
September 15, 2012, 08:45 PM
guess thats why the simple things are best checked first.

fire for effect, brother.

Powderman
September 15, 2012, 09:47 PM
The idea that a rifle upper won't funtion correctly on a carbine lower is absolutely bogus. I can swap any of 4 different barrel lengths onto either a carbine stocked lower or an A2 stocked lower and run 55-69 grain bulleted ammo as good as any.

I didn't say that.

A CARBINE length upper works on a very different set of dynamics than the rifle upper. It cycles much more violently. The volume of gas is much more. Thus, the heavier buffer weights, ranging from light (no mark) through H, H1, H2 and H3--the last one being filled with three tungsten steel weights. VERY heavy.

By the way, the buffer's job is not to only soften the recoil impulse. When the proper buffer is used, it also prevents carrier bounce.

Thus, you use a rifle length buffer and the proper spring when shooting a 20 inch barreled upper, and the appropriate carbine length spring and H buffer when using the carbine top end.

Cordially,

your friendly neighborhood Powderman
(Colt factory certified AR/M16 system armorer)

PS: By the way, the problems evident in the pictures of your live rounds points to a defective magazine. You might want to make sure that you have good magazines; look for a CAGE (Civilian and Gov't Entity) code on the side of the mag body. This tells you that the magazine has been accepted by DOD as a military-quality magazine.

Make sure you have good followers in it, and some springs in good condition. I would also check your buffer spring (AKA action spring), to make sure it is serviceable and is the correct length for the configuration you're using.

impalacustom
September 15, 2012, 10:35 PM
Mobuck, get yourself a buffer and spring for the 9mm 10.5" barrel and then put your 20" rifle barrel upper on that lower then go shoot some PMC Bronze, watch what happens. Then the 9mm 10.5" barrel upper and put it on the rifle buffer and spring lower and see how long it takes to break the gas key off as the gas key becomes the stop for the BCG.

ky hunter
September 16, 2012, 12:17 AM
I use grease in my AR clean it out after 5 hundred rounds or so along with a barrel cleaning. finish up with new grease on moving parts and rails lite oil patch down the barrel good for 500 + - more. If you are worried about dirt getting in your grease just keep a mag in and dust cover shut. Like that rifle you have:D

madcratebuilder
September 16, 2012, 06:37 AM
I just finished lubing the heck out of it with high temp bearing grease.

Remove the bearing grease. Only place the AR can use grease is the bolt carrier rails, these four narrow rails are the contact point between the upper and carrier. It needs to be a very light grease like Tetra gun grease or Lubraplate 135A. The piston area of carrier and the tail of the bolt and gas rings need to be wet with oil.



someone has mated a carbine buffer and tube with a rifle top end.
The result is the dreaded "carfle"--a combination rifle and carbine that doesn't do either job well.
To isolate the problem, switch out your buffer, tube and stock with a normal sized stock meant for the full sized rifle. I'm willing to bet that your problem will resolve itself.

The OP's rifle has a Vltor A5 RE. This RE is rifle length and uses a rifle buffer and spring. This is the RE the USMC has adapted for their 20" rifles.



impalacustom - I've going to put a few rounds through sloppy wet. If it still fails, I'll try an h2. Thanks.

You well need to change the RE to use a H2 buffer. The A5 uses a rifle length buffer.

Buffer weight is not the problem. You can swap rifle to carbine in any compilation and it should run fine.

I would double check the gas block to gas port alignment. I think you have a under gas problem.



OH, PALEASE GIVE US A BREAK!
The idea that a rifle upper won't funtion correctly on a carbine lower is absolutely bogus. I can swap any of 4 different barrel lengths onto either a carbine stocked lower or an A2 stocked lower and run 55-69 grain bulleted ammo as good as any.
I will assume this is/was a newly assembled upper??? If so, it should have been dripping to begin with and sputtering and smoking with every shot.
As for lube, I use CLP on the BCG, red wheel bearing grease on the cam pin&bearing surfaces of the BCG/bolt lugs, and Remlube on the trigger/hammer pins.

mobuck nailed it.;)

Marquezj16
September 16, 2012, 08:27 AM
Here's a way to break it in without using so much ammo and getting some practice along the way. Lube your BCG with a gun oil. Do not insert mag. Do not load ammo. Charge the weapon, pick a small target, aim and dry fire. Now repeat 400 more times. :D