AR not chambering next round

CUSTOM441

CUSTOM441

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I picked up my first AR, a circa 2002 Bushmaster XM-15 E2S from the EE and have had it out to the range twice. The first time I had one failure to feed, but after I cycled the charging handle it chambered the next round fine and kept on trucking. I cleaned the rifle after this shoot.

Took it out today for the 2nd time to get the backup irons on target and was having constant failure to feed problems. After hitting the bolt-release, the first round chambers fine, then after the first shot all I get is a *click*. No round in the chamber. Manually cycle the charging handle, next round feeds and fires fine. Repeat.

I tried several different magazines (a 5/30 STANAG, and 2 LAR-15 mags), I took out the bolt and sprayed it with CLP, then sprayed the BCG itself, wiped off the excess, but no joy. Same issue. Also worth noting the BCG would not hold open on the last round in any of these mags either.

I'm running cheap steel cased MFS .223 REM 55gr HP. I know I know, not the best ammo around and the AR elitists will probably slam me. Regardless, could this stuff maybe be too weak to completely cycle my bolt? I'm hoping it's an under-gassing issue that can be solved with better ammo, and not something more serious. I'm brand new to the AR platform so any and all advice would be greatly appreciated!
 
Yes sounds like it could be gas issue, enough to eject round, but not enough to chamber new one?

Or could be a spring/buffer issue too

Don't think it's the ammo, unless you have a very picky rifle. I would try different ammo though to rule it out
 
Sounds like short stroking to me (the bolt needs to come farther back to pick up the next round then it does to eject the fired round).

When you cleaned it, what did you take apart? Might you have put something in/together wrong?
 
Newb to ARs myself...so grain of salt and all that...but have you inspected the gas port/block and gas tube? I try and tear down all used rifles I buy just to be sure all is well.
 
Any idea what the round count is on the rifle? It's possible, though very unlikely, that you have a partially plugged gas tube.

Since you tried different magazines, and the rifle won't feed or the bolt hold open on either ones, that would seem to rule out magazine issues.

Try different ammo and see what happens. If you still have the same issue, you might look at your gas rings on the bolt. They could be worn.
 
berger said:
have you inspected the gas port/block and gas tube? I try and tear down all used rifles I buy just to be sure all is well.
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When I first got the rifle and before ever shooting it I took the entire thing apart, cleaned and lubed it and made sure all is well. Literally everything, except the gas system. It has a free float tube on it with a low-profile gas block. To be honest it's the only part of the upper I don't know how to disassemble, and it seems a bit daunting. I will look into this tonight and see if I can't take the thing apart and have a look.

shredder said:
Any idea what the round count is on the rifle?... If you still have the same issue, you might look at your gas rings on the bolt. They could be worn.
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The round count is ~600 and I'm the 3rd owner.

I'll do the gas ring test when I take the rifle apart for cleaning and report back. Either way, this part seems cheap to replace so I'm debating just doing it anyway. Is it easy enough to DIY?
 
Check your gas rings on your bolt Sir.
Flick the bolt outward and try to stand the bolt up on its face on a table.
If the carrier can't stay up under its own weight without dropping/camming it's a good indicator that your gas seal rings on your bolt are shot. Easy fix.
Try that first and see if it fixes the problem.

If it's an allan key low pro gas block that is a common problem as well (that's why I don't use them, pins all the way!).
 
Travis Bickle said:
Check your gas rings on your bolt Sir.
Flick the bolt outward and try to stand the bolt up on its face on a table.
If the carrier can't stay up under its own weight without dropping/camming it's a good indicator that your gas seal rings on your bolt are shot. Easy fix.
Try that first and see if it fixes the problem.

If it's an allan key low pro gas block that is a common problem as well (that's why I don't use them, pins all the way!).
Click to expand...

Good advice, if it's a screw-on gas block that uses hex screws it might've loosened just enough to move forward a bit. Checking the gas rings is also a good thing to do.

Gas tubes don't get obstructed unless you shoot .22LR through it or something. Believe me, C7 and C8 gas tubes go for literally tens of thousands of rounds and blank ammunition on full auto and never get clogged.
 
300Spartans said:
Is this rifle an "A2" type rifle, with 20" barrel and A2 stock system?
Click to expand...

16" Heavy barrel, carbine length gas system, A2 style buttstock with commercial buffer tube.

Travis Bickle said:
Check your gas rings on your bolt Sir.
Flick the bolt outward and try to stand the bolt up on its face on a table.
If the carrier can't stay up under its own weight without dropping/camming it's a good indicator that your gas seal rings on your bolt are shot. Easy fix.
Try that first and see if it fixes the problem.

If it's an allan key low pro gas block that is a common problem as well (that's why I don't use them, pins all the way!).
Click to expand...

Tried the gas ring test after I cleaned it, it seems to pass! I'll have a look at the free float hand guard and remove it to check out the gas system
 
Sounds to me like an issue with the gas system. Make sure your gas block is not misaligned and make sure your gas tube is not leaking or obstructed. Check the end of the gas tube where it mates with the bolt carrier key...it may be bent or pinched.

I would also also make sure their is nothing obstructing your buffer/spring assembly from going all the way back into the buffer tube.
 
check gas block, tube for obstructions or misalignment in relation to port (clamp-on)..
check for binding on buffer or spring...
check for bolt for adequate lubricant (generous and frequent application IMHO), proper assembly, and tightness/alignment of gas key while you are at it..
Other than bad ammo I can't think of anything else.

I like my bolt wet looking with lube in summer and less in winter. I use a silicone liquid oil lube or the Lucas gun oil in my shootin box. I have had it dry up and misfeed one or two times early on....
 
CUSTOM441 said:
16" Heavy barrel, carbine length gas system, A2 style buttstock with commercial buffer tube.



Tried the gas ring test after I cleaned it, it seems to pass! I'll have a look at the free float hand guard and remove it to check out the gas system
Click to expand...

Carbine gas systems are very reliable for cycling especially with the 16" barrel! Lots of dwell time to keep the pressure high and push that f**ker backwards.
Without seeing the rifle I would bet strongly on the gas block. Check the alignment. The hex screws may have loosened and it may have turned slightly or even pulled the gas tube forward with it.
If your bolt gas check rings are solid then that's where I would put my money.
Someone else also mentioned, check your gas key on top of your bolt. If it's not properly staked, try and tighten the hex keys with an allan wrench. If they turn (ie they were loose) that could very well be the problem. It could even be a combination of both.
Torque the gas key bolts down to around 35-40 inch pounds, then get a good quality spike tipped punch and stake the sides of the carrier into the hex screws. Just make sure it's supported properly and use small, steady taps with the hammer working the steel into the hex screw. They sell a "tool" for this but it's for douches with more money than brains/skill lol
Let us know how it goes after this.
 
As far as running my bolt wet, I've sprayed it with CLP, distributed it with my fingers and put it back in the bolt carrier. I then apply CLP to any areas that appear shiny on the BCG, assuming this is where there is friction.

I removed/checked and lightly oiled the buffer and spring. Seems to function fine with no obstructions.

I checked the gas key. It seemed properly staked with no sign of shifting. I tried torquing the hex screws to be sure and there were rock solid.

I then removed the free float tube and checked the two hex screws on the bottom of the low pro gas block and they seemed relatively tight. I removed them anyway and pulled the gas block forward to inspect the gas tube, no bends or kinks. I don't have a small enough punch to remove the roll pin in the gas block to inspect the inside of the gas tube, I suppose this is next. My next question for putting the gas block back on.. there seems to be about 1/4" play in the gas block before I set the screws. How do I tell if the gas block is aligned properly? There's no way to reference the gas port to be sure. I'm assuming this is my problem, since everything else I've tried seems to be okay.
 
CUSTOM441 said:
As far as running my bolt wet, I've sprayed it with CLP, distributed it with my fingers and put it back in the bolt carrier. I then apply CLP to any areas that appear shiny on the BCG, assuming this is where there is friction.

I removed/checked and lightly oiled the buffer and spring. Seems to function fine with no obstructions.

I checked the gas key. It seemed properly staked with no sign of shifting. I tried torquing the hex screws to be sure and there were rock solid.

I then removed the free float tube and checked the two hex screws on the bottom of the low pro gas block and they seemed relatively tight. I removed them anyway and pulled the gas block forward to inspect the gas tube, no bends or kinks. I don't have a small enough punch to remove the roll pin in the gas block to inspect the inside of the gas tube, I suppose this is next. My next question for putting the gas block back on.. there seems to be about 1/4" play in the gas block before I set the screws. How do I tell if the gas block is aligned properly? There's no way to reference the gas port to be sure. I'm assuming this is my problem, since everything else I've tried seems to be okay.
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Don't remove the gas tube as this is the least likely area that ever plugs up. Is the gas block a credit card thickness distance away from the forward Handguard ring shoulder? Do you have the ability to try some one else's lower on your uppe? Do the gas ring test and check their condition. Try a number of brands of ammo, 5.56 and .223 for functionality.

To properly align the tube mark the shoulder adjacent to the gas port and sharply the underside of the barrel, just below the port. When installing the block only use the front Allen screw and temporarily leave the back one out. This hole is directly below the gas hole in the gas block so align it over the sharply mark.

Green loctite can also be used to seal off the gap on a poorly fitting gas block.
 
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Sqr said:
To properly align the tube mark the shoulder adjacent to the gas port and sharply the underside of the barrel, just below the port. When installing the block only use the front Allen screw and temporarily leave the back one out. This hole is directly below the gas hole in the gas block so align it over the sharply mark.
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I can tell you just from looking at it that the gas port lines up with the rear allen screw on the gas block. Since the tube is already attached to the block I can't tell where the hole is on the inside of the block. I'm assuming it's top dead center. I drew a pencil line from the center of the gas port straight down the barrel so it's still visible when I slide the gas block into position. I lined up top dead center of the gas block with the pencil mark. Crude, but it's the only thing I can think of off the top of my head..
 
A sharpy mark adjacent to the port on the Handguard cap ridge will give you the East to West alignment and the sharpy mark on the underside of the barrel will assist with the north to south.
 
Check the end of the gas tube to ensure it isn't worn out.
If you look at my pic below You will see what the end of a worn gas tube looks like compared to a new one.
I had cycling issues till i replaced my gas tube.
Another thing to check when looking at the gas block is to see if there is a space between the end of the gas block and the barrel stop.
There should be a small gap of around 0.030". Typically the front set screw is in line with the hole in the gas block.

As a general rule a bolt should be able to cycle on a 16" barrel even with 2 missing gas rings.
I would first try with a P-Mag and different ammo if everything else checks out.

 
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