Stag Arms Model 15 Failing to Feed

[308]

"you might be a redneck if youve ever had to use oil from your truck dipstick to lube your AR15"


i love it

Mobil-1 baby!

 

[v0lcom13sn0w]

Mobil-1 baby!

o believe me. i use all sorts of automotive oils and lubes on my guns...

 

[AlphaFreeze]

Do you have another AR to swap the upper and lower to see which part the problem follows?

No this is my only AR.

sounds like time for a call to the MFG.

Yup. Doing that tomorrow.

I lubed it heavily then manually cycled it probably 200-300 times. Then tried to cycle 4 magazines containing 30 rounds each and the problem persisted except when the magazines had less than 5 rounds in them.

 

[nwslopoke]

No this is my only AR.

I've heard this was possible but I never wanted to believe it was true!

 

[AlphaFreeze]

I've heard this was possible but I never wanted to believe it was true!

Yuuup. My first AR was a Ruger AR556. That thing ran like a champion. It would shoot anything I'd put in it, it'd feed from any magazine, and I went through probably 2000 rounds before the first cleaning and I think I only ever had 1 FTE. Had to sell it when I got a job in eastern Oregon and needed money to move from Portland.

Now that I have a well paying job, I decided to get myself a quality AR15. Then I wound up with this poor excuse of a rifle from Stag. I might just sell it and take my losses and go get another AR556.

 

[nwslopoke]

Now that I have a well paying job, I decided to get myself a quality AR15. Then I wound up with this poor excuse of a rifle from Stag. I might just sell it and take my losses and go get another AR556.

I have a Stag 3T for several years. It hasn't missed a beat. It was under the old ownership so maybe the quality took a dip but I doubt they changed their tooling. I also ham fisted my own AR15 PSA build that's stayed in one piece and may be my best rifle (if I do say). Just to say it ain't rocket science. I'm sure your issue will be simple.

Ask and I'm sure someone will let you use an upper. Those are not a transfer item. Maybe even a gun range or shop if you frequent one.

 

[v0lcom13sn0w]

Yuuup. My first AR was a Ruger AR556. That thing ran like a champion. It would shoot anything I'd put in it, it'd feed from any magazine, and I went through probably 2000 rounds before the first cleaning and I think I only ever had 1 FTE. Had to sell it when I got a job in eastern Oregon and needed money to move from Portland.

Now that I have a well paying job, I decided to get myself a quality AR15. Then I wound up with this poor excuse of a rifle from Stag. I might just sell it and take my losses and go get another AR556.

the rugers are nothin to sneeze at. theyre good ARs. the M&P sport 2 is supposed to be good too. and i hear ruger is coming out/ came out with like the "next step up" from the AR556. its like the ruger MPR or somethin like that. optics ready.





all of mine are all assembled by me in my garage from parts kits and well researched parts.each one has its purpose and the amount of money ive put into them shows. i have ones that i would ask $300 for and ones i would ask $2500 for. they all work!

 

[AlphaFreeze]

all of mine are all assembled by me in my garage from parts kits and well researched parts.each one has its purpose and the amount of money ive put into them shows. i have ones that i would ask $300 for and ones i would ask $2500 for. they all work!

My plan was to get this one AR to re-familiarize myself with the platform since its been a few years. Then once I get my own house (looking at it very soon, I just rent right now), I was gonna look at assembling my own AR since I could have a workshop in my garage. About to send Stag an email and be like "my bubblegum is bubblegumed up".

 

[HB of CJ]

Stag Arms is on the short list for that planned Left Hand AR10 Retro 20" rifle BUILD with the detachable A2 top carry handle assembly and the OEM steel taper pin A2 front site assemble. Still not sure about finding compatible A2 rifle furniture. The 7.62x51 20" LH barrel is also a concern.

 

[DirectDrive]

OP, if you are seeing shavings around the feed ramps and scrapes on the bullet noses maybe there is something wrong with the way the top cartridge "presents".
The cause could be the magazine feed lips, feed ramp geometry or the way the mag is held in the lower.
Since you've already tried several mags it may not be a mag problem, although I would try a "known good" Pmag and a "known good" USGI mag before I ruled out a mag issue.

The link below is one of the best explanations of AR "cartridge management" within the rifle.
It's focus is 6.8SPC and tweeking mags, but you can hit the pic links (they still work) to see what the top cartridge and feed ramps should look like. Compare it to yours.
This excellent tutorial was done by Harrison, owner of AR Performance.
Recommended Mags

 

[AlphaFreeze]

OP, if you are seeing shavings around the feed ramps and scrapes on the bullet noses maybe there is something wrong with the way the top cartridge "presents".
The cause could be the magazine feed lips, feed ramp geometry or the way the mag is held in the lower.
Since you've already tried several mags it may not be a mag problem, although I would try a "known good" Pmag and a "known good" USGI mag before I ruled out a mag issue.

I emailed stag about the issue and included these two images with my description of the problem. As you can see, it looks like the round is getting hung up on the feedramp. You can see the scratches and damage to the bullets that the feedramp does to them.

https://i.imgur.com/dtRSo77.jpg
https://i.imgur.com/sWAPi0H.jpg

I'm hoping its not the mags. Especially if its the factory mag is having the issue. I bought this rifle with the intent of building it to be a HD/SHTF rifle. I want it to be able to run to the ends of the earth but it seems that it can't even run to the end of a magazine.

 

[HB of CJ]

Can you open the rifle and show us some good close up pics of the feed ramps of your upper? Both the receiver and the barrel extension.

 

[DirectDrive]

Can you open the rifle and show us some good close up pics of the feed ramps of your upper? Both the receiver and the barrel extension.

This ^^^
Need good pic of the ramps.
Also a pic just like Harrison's (in the tutorial above) showing how the top cartridge "presents" as it is sitting in the mag with the bolt locked back. This will be telling.

That looks like a 6.8 ?
If so, sometimes they don't feed well over 5.56 ramps.
The solution is often to widen the ramps and ease the sharp edges.
However, I am not a fan of putting the Dremel to feed ramps and namely cutting into the receiver if at all avoidable.
What I do if it were mine, would be to carefully study Harrison's tutorial and perform the described "tweeks" on one magazine and then test that as a first step.

If this is a 6.8 then EVERYTHING is Harrison's tutorial (that I posted above) would pertain to your rifle.
Also PRI are considered to be the best mags for 6.8
68 Forums is your huckleberry for all things 6.8

 

[AlphaFreeze]

Can you open the rifle and show us some good close up pics of the feed ramps of your upper? Both the receiver and the barrel extension.

This ^^^
Need good pic of the ramps.

https://i.imgur.com/B0zh6IY.jpg
https://i.imgur.com/RGMkrYn.jpg
https://i.imgur.com/KckhsQp.jpg

 

[DirectDrive]

https://i.imgur.com/B0zh6IY.jpg
https://i.imgur.com/RGMkrYn.jpg
https://i.imgur.com/KckhsQp.jpg

Those are clean-looking ramps.
Is this a 6.8 rifle ?

Here's Harrison's pic (from the tutorial) of the desired position for the top cartridge...

Can you show your rig from the same angle ?

 

[AlphaFreeze]

Those are clean-looking ramps.
Is this a 6.8 rifle ?

223/556. I'm tempted to go buy myself 1 Pmag today and see how it works in the gun.

 

[AlphaFreeze]

Those are clean-looking ramps.
Is this a 6.8 rifle ?

Here's Harrison's pic (from the tutorial) of the desired position for the top cartridge...

Can you show your rig from the same angle ?

 

[HB of CJ]

Great pictures and thank you. I think I see things not quite right.

1) Buy a couple of sheet of 200, 400 and 600 grit wet dry sand paper. The crockus cloth type. Find a common pencil with half an eraser. Use the pencil as a polishing tool. Run the crockus cloth dry up and down the feed ramps. There should be zero bumps or notch between the aluminimimmumm receiver and the steel barrel extension. The M4 feed ramp extension on the upper MUST blend in exactly smooth with the barrel. Polish until very smooth. Extremely smooth.

Do this dry. No water or oil.

2) That pesky gas tube has my attention. That gas tube MAY not be exactly centered. Sloppy build? Maybe. Dunno yet. Try the "plop" test. No better name for it as far as I know. Strip your bolt carrier group. Open the rifle and separate the upper and lower halves. Place the muzzle on the floor. Drop the stripped carrier into the upper. It should drop free to the end of the barrel WITHOUT touching the gas key. Zero interference. PLOP. No touching the gas tube allowed. Then ....

3) Strip out the gas tube and eye ball it. Takes about 30 seconds. You will need a proper roll pin punch, (the dinky one that bends) and a small ball peen hammer. Any hammer will work. Tap out the gas tube roll pin. You can use it over and over. Grab hard and rip out the gas tube. Eyeball that pesky gas tube to see if it is exactly straight with no EXTRA bends. It has a factory bend. Slight. You want to look for LATERAL bends where a builder bent the gas tube to make it fit.

There is a lot of brass or gilding metal fouling in the barrel extension. How it got there I am not quite sure. Clean it out.

If the gas tube either fails the "PLOP" test or if you find the gas tube was bent to make it fit, it means the build is a piece of shiet and needs to be returned to the manufacture. I am also curious how the gun prints left to right shooting straight down the pipe. The rear site aperture must be within 2 to 4 clicks exactly centered with the rifle shooting exactly straight right to left. No moving the rear site around. 100 yards. If you can do all of the above we would have a better idea.

Sloppy feed ramps and an off centered gas tube can steal energy from the round feeding and cycling. Off centered rear sites means the build is garbage and never should have left the factory. Stag Arms already understands this. If the rear sites are off it means the barrel was NOT indexed at all and the build was never test fired for accuracy. Any one of the above FOR ME would mean returning the rifle to Stag Arms for an exchange or a total re barrel torque job. Yep!

Respectfully. hundreds of builds. uncounted rebuilds.

 

[DirectDrive]

View attachment 416226

That looks low.
Do you see the difference ?
Harrison's bullet tip is lookin' at daylight.
Yours is lookin' at the bottom of the feed ramp.

What kind of mag is that ?

If you buy anymore mags, go here for the real schitt...
44MAG.com - .223/5.56mm AR15 Magazines
The NHMTG 20 round in the lower right is arguable the most dependable AR mag.
It's what was originally designed for the rifle, but Okay, NHMTG and Pmag are all good mags.

 

[HB of CJ]

DirectDrive nails it and thank you DD. I missed that. Looked right through it. Easy to conduct another quick spec check. Run your middle finger, (yep) up the mag well and finger that mag catch arm and tit. The mag catch arm MUST slightly protrude into the mag well. Flush is very bad. Slightly high is ever worserer. Very low probability of this. Computerized tooling with bad tapes let this happen years ago. Long since fixed or so we hope.

Another easy spec test. This one eyeball checks the height the magazine sits at when clicked into the lower. Open the rifle. Click in your mag of choice and use. Retract the bolt group and let the bolt stop work. The bolt head must just clear the top of the mag. The carrier should also just clear the top of the mag. You will have to use the bolt release to conduct this check. NO AMMO. See that the bolt and carrier clear the feed lips of the mag.

Then SAFELY use fired case. Load up a handful of fired cases into the mag. Gently hand cycle the fired cases. See how much the bolt head engages the rear of the brass when it strips it off the magazine. This is an experience thing. No real way to describe the amount of engagement between the brass and the bolt head. Some videos show this quite well and explain it.. DD has it right. That round looks very very low in the mag well. Could be just me.

Respectfully. HB