View Full Version : Adams Arms/VLTOR A5 fail to eject
Over the past few months I have pieced together a new AR. I took it out to the range for the first time today to test it out and zero it in. The gun fires but will not eject the round with a magazine in the mag well, no matter how many rounds are left in the magazine. If I fire with an empty mag, the bolt does not make it far enough back to lock back. Further, the charging handle is very difficult to pull back after firing, whether or not I have already ejected the mag. Once I get the bolt back, the brass flies out just fine, and I can slide it back and forth with the charging handle with no problem. If I fire without the magazine in the mag well, it spits the brass out just fine, about 3 or 4 o'clock.
Any help is much appreciated!
Details on the gun and ammo are as follows:
Upper:
Adams Arms 16" 1:7 twist piston upper chambered in 5.56
Lower:
Seekins Forged Lower
VLTOR A-5 Buffer tube and buffer (standard weight)
DSA (I think...) rifle-length spring
LWRC (overpriced, I know now) lower parts kit
Ammo: Independence 55 gr 5.56 xm193i
Mags: 30rd Pmag, 30rd Lancer L5 AWM
Have you generously lubed the BCG? Good idea to lube the CH as well.
Is the gas block adjusted to the 12 o'clock position (normal fire)?
Is the BCG catching on anything as it moves back? Is there anything impeding the CH range of motion?
Is the gas block aligned correctly on the barrel?
If your upper is still under warranty with AA, I'd contact them for support before you start disassembling/swapping parts. You might also want to try some Federal 5.56 to rule out ammo as a suspect.
Unsolicited advice: return that upper if you can, or get AA to fix it then sell it. If you want something that just plain works, buy a quality DI upper.
If you read the instructions, the AA system is designed around a carbine spring and buffer...
What is the weight of the "Standard" buffer A-5 buffer. If it is the H2 it may be too heavy. IIRC Adams Arms recommends and H buffer for semi and an H2 for full auto/select fire. A carbine H buffer is about 3.8 oz and an H2 is about 4.6.
A-5 buffer weights:
H0, 3.8 oz
H1, 4.56oz
H2, 5.33oz
H3, 6.08oz
H4, 6.83
Call Adams Arms and ask what buffer weight they recommend. Once you get it running then play with buffer weights to smooth it out.
The standard A5 buffer is the A5H2. It has 2 steel & 2 tungsten weights. If you have a standard carbine or H buffer pull the A5 & carbine buffer apart. Remove the two rear/tungsten weights out of the A5 buffer and replace with steel. That way you just made your own A5H0. If that doesn't work I'd just take off the Vltor RE. If it does work then bump the weight up to simulate the A5H1. If that works then your done.
IF the problem is solely the A5 and it sounds like it. Curious to know how much difference the A5 would make on a piston gun.
-Jax
ETA: This piston illness can be easily remedied with a liberal dose of direct impingement. ;)
Mall_Ninja
08-01-13, 20:34
I think these guys missed the fact you said that the charging handle is very hard to pull back after firing. This means something is binding, that is what is causing your short stroking, not the buffer weight. Since you built it either you did something wrong or a part is out of spec. If you tried more than one mag and it does it with all mags, then something in your bolt carrier or upper is binding. The mag is pushing up against it making it worse...
...Further, the charging handle is very difficult to pull back after firing, whether or not I have already ejected the mag. Once I get the bolt back, the brass flies out just fine, and I can slide it back and forth with the charging handle with no problem.
I didn't miss the charging handle comment. It just sounded like expanded brass stuck in the chamber. It sounded as if the gun short stroked and drove the empty brass back into the chamber. Once the chamber is clear, the bolt and charging handle move freely.
It it could be something with the chamber, not reamed properly... To start I would check the buffer. A 5.33 oz buffer seems too heavy. I do not have any experience with A5 buffers and did not know the weights are interchangeable with carbine buffer weights, but since they are "jaxman7's" advise is good.
az,
All the weights are interchangeable except for closest one to the buffer pad. That one has a cutout for the spring that is mounted.
-Jax
K.L. Davis
08-01-13, 21:37
Sounds like the bolt is dragging on the mag... did you try another mag?
Thanks for the replies guys. Lets see if I can answer your questions...
I lubed the gun with frog lube. Honestly, frog lube doesn't really leave that "slick" feeling that oil does. Is it possible that frog lube isn't enough lubrication for a brand new gun?
Yes, I tried the fun in both 12 and 1 o'clock positions. 12 operates as I described, 1 results in no cycling at all 9 out of 10 times.
I have no idea if the gas block is aligned properly. This is a brand new AA upper, so I would assume it is still under warranty, and I have contacted them to see if they have any ideas.
My buffer is the 5.33oz one.
I tried it with a pmag and a lancer l5 awm. Both 30 rd, both with different numbers of rounds loaded, from 28 to 0. And I tried it with no mag at all, and it ejected just fine. Could there be something with the way I installed my mag catch or something that is holding the magazine too high?
Magazines either empty or loaded create drag on the bottom of the bolt carrier. The fact that you can extract and eject an expended casing without a magazine in the firearm tells me you are on the cusp of functioning. The questions that are not answered without the magazine in the gun is whether or not the bolt carrier is traveling far enough to the rear to pick up a fresh cartridge or lock the bolt to the rear if it did have a magazine.
Lighten your buffer by adjusting the weights as jaxman7 pointed out and I believe your gun will cycle.
You can check the gas block alignment on your Adams Arms by laying the top rails flat on a piece of glass. Between the flat top upper and rail on top of the gas block they should sit flat without any rocking side to side. Next take your piston rod out and remove the spring and "spring cup." Reinstall the rod without the spring and spring cup. With the muzzle pointed up and the tip of the piston rod resting on the bolt carrier, push the bolt and carrier forward (into battery) with your thumb. When the bolt and carrier are in battery, there should be .015 - .025 clearance between the piston rod and back of the gas block. (Measure with a feeler gauge or if you do not have a feeler gauge a business card will get you close.) If the rails are flat and you have the required clearance the gas block should be aligned.
Do you have another functioning AR available to test the upper and lower separately? Preferable one with a carbine buffer and spring. Two complete and working ARs would be even better.
Try your AA upper on a known-good lower, and your lower with a known-good upper. Isolate which half is causing the problem. It could be both, however.
If I fire without the magazine in the mag well, it spits the brass out just fine, about 3 or 4 o'clock.Honestly, I don't think the A5 is your problem. Assuming your ammo is full-power 5.56 and the gun works fine without a mag, messing with the buffer system is not going to fix things. The A5 is actually a good idea to run with piston ARs and confers the same advantages as with a DI upper.
I own two uppers with Adams Arms kits installed. I experimented with buffer weights because I also use a 9mm upper on the same f/a lower. I was trying to find a buffer that would work well with both. If your buffer is too heavy the AA upper will not cycle.
Try Jaxman7's suggestion about changing the buffer weight.
Call AA and speak to them about buffer weights.
PA PATRIOT
08-03-13, 15:29
I have seen this issue before with the AA piston Middy upper and the VLTOR A-5 and you need to reduce the buffer weight to 3.8 oz's for solid function with 5.56/.223 factory brass pressure loads and down to a 3.0 oz's if shooting weaker steel cased.
Now another issue I have also seen on piston guns is bolt carrier tilt which can be exaggerated if the bolt receives to much up-ward pressure from magazine contact. This will cause the charging handle to feel as it is dragging during cycling but the real contact is the bolt trying to aligning its self into the buffer tube.
Look at your buffer tube and see if there is any abnormal wear occurring in the first few inches. If you find none then it maybe be just simple drag on the bolt from the magazine and to much weight in the buffer.
elephantrider
08-03-13, 16:54
Either keep the AA Upper and ditch the Vltor A5 buffer system for a standard carbine buffer system in the weight that AA recommends. You could also look into and anti-carrier tilt type buffer. It doesn't sound like it is worth the trouble of hacking up an A5 buffer to get it to work with an AA piston upper that it was never intended for and visa-versa (AA piston was not designed to work with the Vltor A5).
... or, ditch the AA upper for a good quality DI upper that will work well with the Vltor A5 system.
My recommendation would be to unload the AA piston upper. I don't understand the attraction of the piston kits when a good DI upper works fantastic with the Vltor A5 system. The piston system just seems to complicate things and introduce new problems such as carrier tilt.
There is nothing wrong with your setup other than your buffer weight. Just like carbine buffers, A5 buffers are sold in various weights. An A5 H0 buffer is what you want. You can either purchase one, or convert yours. Personally, I would convert mine because that way I can experiment with varying weights until I find the weight that works best. PA Patriot's suggestion of 3.8 oz sounds right on the money. An A5 H0 weights 3.8 oz. No need to change your entire upper or receiver extension...
PA PATRIOT
08-04-13, 18:16
I see there are some folks who recommend the OP dump the AA piston upper but I have to disagree with that opinion. Why dump any single platform without the very simplest of trouble shooting measures. I understand there is always resistance to going outside the established norm's which is the DI system but if you look at the latest offerings from Colt and HK they seem to be focusing on the piston driven system. I run both DI and Piston guns and found they each have their own strengths and weaknesses which I use accordingly for the mission at hand to capitalize on the capability I need at the time.
Currently I like the piston design to run steel cased at courses were the round count is high and in colder weather during three gun. My DI guns are set up for serious use both SD and ranged engagement but if I had to run a piston gun for the same mission I would not hesitate.
BufordTJustice
08-05-13, 03:48
I see there are some folks who recommend the OP dump the AA piston upper but I have to disagree with that opinion. Why dump any single platform without the very simplest of trouble shooting measures. I understand there is always resistance to going outside the established norm's which is the DI system but if you look at the latest offerings from Colt and HK they seem to be focusing on the piston driven system. I run both DI and Piston guns and found they each have their own strengths and weaknesses which I use accordingly for the mission at hand to capitalize on the capability I need at the time.
Currently I like the piston design to run steel cased at courses were the round count is high and in colder weather during three gun. My DI guns are set up for serious use both SD and ranged engagement but if I had to run a piston gun for the same mission I would not hesitate.
I understand what you are saying, but if a gun won't run with the A5 and a standard buffer, which successfully emulates the most reliable buffer system extant, then I say the educated troubleshooter has to start asking the question "why won't my gun run with a rifle buffer/A5?"
I have a buddy who bought a CMMG piston AR back in 2008. It had been nothing but problems for him using all types of factory ammo until he sent it back to CMMG. They replaced the entire upper and sent it back....now it runs OKAY. It still NEEDS a a BCM extractor spring WITH the o-ring and insert to extract properly, but yet will malf with anything heavier than a carbine weight buffer.
Why deviate so far from the original design, only to have slightly more muzzle rise, a sharper recoil impulse, and no more resistance to dirt/carbon?
I'm all for troubleshooting the OP's gun in a practical manner instead of immediately demanding that he trash it (I doubt he's made of money), but let's be honest about this: he would likely be better served in all aspects by a Colt 6920's upper half or another quality upper from BCM/DD/LMT etc.
...then I say the educated troubleshooter has to start asking the question "why won't my gun run with a rifle buffer/A5?"
Because it was not designed to. It was designed to function with a H weight carbine buffer.
I have a buddy who bought a CMMG piston AR back in 2008.... It still NEEDS a a BCM extractor spring WITH the o-ring and insert to extract properly, but yet will malf with anything heavier than a carbine weight buffer.
Several DI guns need buffers of varying weight and an extractor spring...
Why deviate so far from the original design, only to have slightly more muzzle rise, a sharper recoil impulse, and no more resistance to dirt/carbon?
I would say it is good advice if he did not already own a piston upper that he can get functioning properly for little or no money by changing weights in the buffer. I would even advise converting it to DI by buying a gas tube, gas block and bolt carrier before I told him to dump the whole upper. He could sell the piston kit and pocket some money instead of laying out more money.
Responses in red.
BufordTJustice
08-05-13, 13:32
Responses in red.
"Because it was not designed to. It was designed to function with a H weight carbine buffer."
It wasn't designed with any consideration of the sort. All first gen AA piston systems were replacement uppers and carried no such caveat. I have seen several. Their original product was simply a piston conversion kit that could turn a DI upper into a piston upper....which incorporated an amalgam of the design features found in the then-new LWRC/POF systems. Again, no such requirement for buffer weight was made. I've seen the original AA manuals.
"Several DI guns need buffers of varying weight and an extractor spring..."
Yes, but you didn't state the reason. The piston guns need uber-power extractor springs and heavier buffers because of their far-faster-than-EVER-INTENDED extraction. This is why many piston guns cannot digest steel cased ammo. CMMG (which started with an AA piston setup) specifically prohibits the use of steel cased ammo in their piston guns.
"I would say it is good advice if he did not already own a piston upper that he can get functioning properly for little or no money by changing weights in the buffer. I would even advise converting it to DI by buying a gas tube, gas block and bolt carrier before I told him to dump the whole upper. He could sell the piston kit and pocket some money instead of laying out more money."
If he modifies the upper, it turns into a franken-gun and the resale value is destroyed. Piston conversion kits run for ~$175-$250 retail. For maybe twice that he can buy an all new quality upper (BCM, HELLO?). Instead of trying to put lipstick on a pig, he would be better off not dumping a ton of cash into this project.
If the OP can alter the buffer weight and get it to run, fine. Spending much more than that doesn't make fiscal sense. Especially since there are tons of Arfcommers who would have to fight the urge to rub one out before handing over their money ("Piston! Yay!").
BufordTJustice
08-05-13, 15:26
Responses in red.
Also, some added perspective from another recent post of mine:
"...the carbine buffer system was well outside of the intended design envelope created by Stoner/Sullivan. The carbine RE, spring, and buffer was a red headed stepchild created by Colt in order to make a shorter, adjustable stock possible. If you know your history, you know that it took Colt about a decade of making this system before they could get it to function with any advertisable degree of "reliability".
It was a compromise then and it's still a compromise now."
https://www.m4carbine.net/showpost.php?p=1713707&postcount=25
Big thanks for all the discussion guys. I won't be able to work on this for another 5 days or so, but I have plenty to think about. I don't plan on "dumping tons of money" into this upper. It is a brand new upper, and as far as I'm concerned, if it doesn't work, it must be defective. I already put extra money into the rifle by getting the piston upper and the Vltor buffer, because those are the things I wanted, so you're not going to be able to talk me into changing to DI or anything else. I'm going to try my best to get it working like this. I am going to try to fire it on a friend's functioning lower with standard carbine buffer system, and I am going to order a standard carbine buffer so I can play around with the weights (I have none and you definitely cannot find Vltor buffers right now).
One of y'all said something about piston guns cycling much faster than intended. I had heard that too when I was researching for this build. The A5 system with the longer tube and spring and heavier buffer is supposed to slow the cyclic rate. Shouldn't that help me, rather than hurt me?
elephantrider
08-05-13, 20:17
Big thanks for all the discussion guys. I won't be able to work on this for another 5 days or so, but I have plenty to think about. I don't plan on "dumping tons of money" into this upper. It is a brand new upper, and as far as I'm concerned, if it doesn't work, it must be defective. I already put extra money into the rifle by getting the piston upper and the Vltor buffer, because those are the things I wanted, so you're not going to be able to talk me into changing to DI or anything else. I'm going to try my best to get it working like this. I am going to try to fire it on a friend's functioning lower with standard carbine buffer system, and I am going to order a standard carbine buffer so I can play around with the weights (I have none and you definitely cannot find Vltor buffers right now).
Sounds like a solid plan. Try the upper out with the mfg. recommended buffer/spring. That will give you a baseline and let you determine if there is any defect with the upper that you may need to contact AA about.
One of y'all said something about piston guns cycling much faster than intended. I had heard that too when I was researching for this build. The A5 system with the longer tube and spring and heavier buffer is supposed to slow the cyclic rate. Shouldn't that help me, rather than hurt me?
One would assume that the A5 would be a help, but it hasn't helped so far. If the AA upper wont work with the standard weight A5 buffer, that makes me think that the two just don't play well together. Needing to drop down to the lightest A5 buffer is another indicator in my mind that the upper/buffer combo don't mix very well. Most A5 users are able to go heavier than the standard A5 buffer.
Everyone relax and quit pissing in the opposing party's Cheerios. Thanks
elephantrider
08-06-13, 02:35
Now that we are done arguing who said what first and who is more right, let's get back to helping the OP troubleshoot his upper.
Just remembered this thread.
https://www.m4carbine.net/showthread.php?t=135259
That Independence ammo can be very hot. I can't see how that would cause what the OP is experiencing, but keep it in mind if you are still using it.
Definitely test the upper with the buffer configuration that Adams Arms recommends. You want to know if there is an issue that would warrant AA either repairing or replacing it. I strongly suspect there is an issue with it if it wont run on a A5, or those AA uppers are real picky about only using a carbine type buffer.
OP,
As I have mentioned in other threads, you need to isolate the problem. In this case since there is no real starting point, but you mentioned it working without a seated magazine then you need to start by getting another lower.
I would locate a known variable lower (IOW one that works) and I would test the upper on it. If it functions as it should, then you have to start to look at your lower. When you do this make sure to use the same magazines and ammunition.
I would test the lower by using the other upper on your lower and see if there are binding issues. This is just another method of validation. If you know this upper works and you put it in your lower and it now starts to malfunction you can be all but assured this is the issue.
If you put your upper on the other lower and it does not work, then it would be safe to assume that the upper is at fault. I would then look at the following;
1. Is the upper receiver possibly out of spec?
2. Is the charging handle itself out of spec and causing binding?
3. Was the gas block/ piston manufactured wrong? Canted or otherwise.
I would also fully assemble the weapon, and SLOWLY manipulate the charging handle and attempt to isolate the "dragging" Do it with and without a magazine. Maybe the magwell is cut wrong? Maybe the rear of the receiver was cut wrong and the lower receiver extension is crooked. I saw this once (and only once) and when the tube was threaded it was crooked. This caused the carrier to rub inside the tube.
Mall_Ninja
08-06-13, 02:57
Now that we are done arguing who said what first and who is more right, let's get back to helping the OP troubleshoot his upper.
Whats to argue, there is a chronological record in public access! :D
I strongly suspect there is an issue with it if it wont run on a A5, or those AA uppers are real picky about only using a carbine type buffer.
According to Vltors website, they only offer HEAVIER buffers than what is supplied in the "kit". I think putting this upper on a standard carbine lower is the only way to go if it does in fact need a lighter buffer...
There are multiple A5 buffers available. The lightest is essentially equivalent to a carbine H buffer. Unfortunately they are still unobtanium for a little while longer.
Whats to argue, there is a chronological record in public access! :D
According to Vltors website, they only offer HEAVIER buffers than what is supplied in the "kit". I think putting this upper on a standard carbine lower is the only way to go if it does in fact need a lighter buffer...
PA PATRIOT
08-06-13, 08:59
OP,
Are you noticing any abnormal marks or scoring on the bottom of the BCG or the top of your magazines?
FYI,
Things that I did while breaking in my AA uppers was to run them very wet for the first 500rds, kept my buffer weight at 3.8oz with 5.56 pressure loads and swapped out my factory cam pin with a Roller Cam Pin from POF-USA. A few thousand rounds later she is still chugging along without issue.
OP,
swapped out my factory cam pin with a Roller Cam Pin from POF-USA.
What was the reason you decided to do this?
PA PATRIOT
08-06-13, 16:13
All AR's have a certain amount of cam pin gouge which is normal and the wear often stops after a certain point. But I have noticed that AA uppers seem to be a little more critical when it comes to Cam gouging but its a simple and easy fix by either using the Roller Cam Pin from POF-USA or the R.E.P.R. Cam Pin from LWRC.
While this gouging issue will settle down and most likely stop completely with time it is just another friction point for your new build to over come while cycling.
I run the Roller Cam Pin on all my Piston guns and the R.E.P.R. on any new DI gun, for the few dollars they cost it just added piece of mind.
Just got home, been gone for about a week, so I decided to break the gun down and inspect/clean it. I looked inside the RE for any damage. It just looks like the finish is flaking off along the bottom. That's not a big deal, is it?
https://www.m4carbine.net/attachment.php?attachmentid=17812&stc=1&d=1376327342
Mall_Ninja
08-12-13, 14:48
Just got home, been gone for about a week, so I decided to break the gun down and inspect/clean it. I looked inside the RE for any damage. It just looks like the finish is flaking off along the bottom. That's not a big deal, is it?
https://www.m4carbine.net/attachment.php?attachmentid=17812&stc=1&d=1376327342
WOW! This was a brand new RE on this (the piston rifle with issues) lower? Looks like your carrier tilt is putting a whooping on it!
PA PATRIOT
08-12-13, 15:53
You have some problems there for sure, but looking at the two wear marks in the 3' and 9' o'clock positions on the face on the buffer tube ring shows something is really a miss.
ETA,
I don't think carrier tilt is causing this.
The bolt carrier is retracting too far into the receiver extension. I saw the same marks last Friday on a DI 308 with an A5 receiver extension and carbine buffer. Testing the carrier of the 308, it would go into the receiver extension far enough that the widened portion of the bolt carrier made contact with the receiver.
I just pulled one of my AA carriers and it does have widened points that would contact the lower at 3 & 9, just like your photo. In your photo, I can also see marks at 12 o'clock that appear to be made by contact with the bolt carrier.
The carrier will quit making contact with the lower when enough material has been removed/damaged from the receiver and the buffer bottoms out on the back of the receiver extension, like it is suppose to. The wear/damage is unacceptable and should not be happening.
You can test my theory of bolt carrier damage by removing the buffer spring and reinserting the buffer back into the receiver extension. With your bolt carrier push the buffer as far back as it will go and see if the buffer bottoms out before the carrier makes contact with the receiver. If it does not bottom out you will see where the carrier contacts the receiver. If it does bottom out, look and see where the carrier would contact the receiver and it would probably 3 & 9. If it does bottom out, your carrier has caused enough damage/"cut a path of the carrier" and should not cause any more damage.
The bolt carrier is retracting too far into the receiver extension. I saw the same marks last Friday on a DI 308 with an A5 receiver extension and carbine buffer. Testing the carrier of the 308, it would go into the receiver extension far enough that the widened portion of the bolt carrier made contact with the receiver.
I just pulled one of my AA carriers and it does have widened points that would contact the lower at 3 & 9, just like your photo. In your photo, I can also see marks at 12 o'clock that appear to be made by contact with the bolt carrier.
The carrier will quit making contact with the lower when enough material has been removed/damaged from the receiver and the buffer bottoms out on the back of the receiver extension, like it is suppose to. The wear/damage is unacceptable and should not be happening.
You can test my theory of bolt carrier damage by removing the buffer spring and reinserting the buffer back into the receiver extension. With your bolt carrier push the buffer as far back as it will go and see if the buffer bottoms out before the carrier makes contact with the receiver. If it does not bottom out you will see where the carrier contacts the receiver. If it does bottom out, look and see where the carrier would contact the receiver and it would probably 3 & 9. If it does bottom out, your carrier has caused enough damage/"cut a path of the carrier" and should not cause any more damage.
Just tested this. The buffer does bottom out before the carrier hits the receiver. In doing this I noticed that the hammer exerts a good bit of upward force on the carrier. Is this normal?
Failure2Stop
08-12-13, 19:46
Maybe I missed it.
Did the OP contact the manufacturer yet?
Typos brought to you via Tapatalk and autocorrect.
Yes, I contacted Adams Arms, and they recommended using a "standard carbine buffer." If they mean switching to a standard carbine buffer tube/spring/buffer, then I'm not going to try that just yet... I bought the VLTOR A-5 for a reason, and want to try to get it working that way first before I ditch the whole thing. If they mean just using a lighter buffer, then I'd love to, but VLTOR's buffers are impossible to find right now. I'm working on swapping out some weights in my A5H2 buffer to lighten it up, but I haven't gotten around to it yet. I've been on vacation for the past week.
I also contacted VLTOR. After a few e-mails back and forth explaining the problem, I haven't heard from them in a few days.
...the hammer exerts a good bit of upward force on the carrier. Is this normal?
It is normal. Usually the carrier would be installed in the upper and "held in place" while the hammer exerts the upward force on the bottom of the bolt carrier.
elephantrider
08-13-13, 00:06
Just got home, been gone for about a week, so I decided to break the gun down and inspect/clean it. I looked inside the RE for any damage. It just looks like the finish is flaking off along the bottom. That's not a big deal, is it?
https://www.m4carbine.net/attachment.php?attachmentid=17812&stc=1&d=1376327342
That looks like the dry film lubricant being worn off of the inside of the receiver extension. Looks like mostly at the 9 o'clock position. None of the 4 or 5 A5 equipped lowers that I have exhibit anything like that, so I am going to go ahead and say it's not normal.
Yes, I contacted Adams Arms, and they recommended using a "standard carbine buffer." If they mean switching to a standard carbine buffer tube/spring/buffer, then I'm not going to try that just yet... I bought the VLTOR A-5 for a reason, and want to try to get it working that way first before I ditch the whole thing. If they mean just using a lighter buffer, then I'd love to, but VLTOR's buffers are impossible to find right now. I'm working on swapping out some weights in my A5H2 buffer to lighten it up, but I haven't gotten around to it yet. I've been on vacation for the past week.
I also contacted VLTOR. After a few e-mails back and forth explaining the problem, I haven't heard from them in a few days.
Iraqgunz gave you the exact advice you need to isolate your problem and potentially resolve it. There is something out of whack with either your upper or your lower. You need to test them independently with known working upper/lowers in order to figure out where the problem lies. For all you know you upper came faulty from AA. You will never know that until you test it with a known good lower that is set up with the RE/Buffer that they recommend (Yes, they are talking about a standard carbine style RE, and probably an H buffer). You MAY get your upper working by cracking open you A5 buffer and fiddling with the weights, but the wear you are seeing in the A5 RE is a hint that there may be more wrong than just an incorrect buffer weight.
I doubt that Vltor will be able to help you much. The only way that the A5 is causing the problem is if the RE is off center or crooked. It's possible, but I'd guess there is an issue with the upper or lower before that.
Mall_Ninja
08-13-13, 00:25
He has stated that it was the "standard" buffer from Vltor. According to their own site, they ship the kits with the "standard" buffer and only offer "HEAVIER" than standard buffers. So he already has the lightest A5 buffer Vltor offers.
Problem is, if the carrier is traveling so far rearward that its hitting the rear of the receiver, im wondering if he was shipped a standard carbine buffer and not an A5. The shorter standard size carbine buffer stuck into the longer A5 extension would allow the over travel of the carrier and the resulting damage to the lower...
OP can you supply a pick of your buffer? Can you measure the overall length as well?
elephantrider
08-13-13, 01:27
He has stated that it was the "standard" buffer from Vltor. According to their own site, they ship the kits with the "standard" buffer and only offer "HEAVIER" than standard buffers. So he already has the lightest A5 buffer Vltor offers.
That is incorrect, and you have already been told that it is incorrect once before. Please stop re-posting inaccurate information. Vltor makes two buffers that are lighter than the standard A5 buffer. They are listed in the Vltor store.
Problem is, if the carrier is traveling so far rearward that its hitting the rear of the receiver, im wondering if he was shipped a standard carbine buffer and not an A5. The shorter standard size carbine buffer stuck into the longer A5 extension would allow the over travel of the carrier and the resulting damage to the lower...
The OP already stated that he checked and this is not the case, but I guess you didn't bother to read that either?
Mall_Ninja
08-13-13, 02:56
That is incorrect, and you have already been told that it is incorrect once before. Please stop re-posting inaccurate information. Vltor makes two buffers that are lighter than the standard A5 buffer. They are listed in the Vltor store.
The OP already stated that he checked and this is not the case, but I guess you didn't bother to read that either?
Clearly its "not the case", just look at his RE/lower pic that was posted... :rolleyes:
Failure2Stop
08-13-13, 07:00
Yes, I contacted Adams Arms, and they recommended using a "standard carbine buffer." If they mean switching to a standard carbine buffer tube/spring/buffer, then I'm not going to try that just yet... I bought the VLTOR A-5 for a reason, and want to try to get it working that way first before I ditch the whole thing. If they mean just using a lighter buffer, then I'd love to, but VLTOR's buffers are impossible to find right now. I'm working on swapping out some weights in my A5H2 buffer to lighten it up, but I haven't gotten around to it yet. I've been on vacation for the past week.
I also contacted VLTOR. After a few e-mails back and forth explaining the problem, I haven't heard from them in a few days.
Do you not have the ability to utilize a "standard" receiver extension with a carbine buffer? As in; borrow from a friend?
My advice to to do what they are telling you to do and if that does not solve the problem, get a return authorization so that they can fix their product. What you are describing does not sound like a receiver extension/action spring/buffer issue, however, you either play by their rules or take full responsibility for getting it back up and running.
Yeah, I'm going to try to get ahold of a friend so we can go out and switch uppers and see what the deal is. I meant if that works, I'm not going to just settle for getting rid of the A5 and calling it a day. But that is a part of my troubleshooting plan going forward. Unfortunately I'll be lucky if I can get to the range this coming weekend... It may be 2 weeks before I can try anything. I appreciate all the help y'all have given me.
Failure2Stop
08-13-13, 08:08
Yeah, I'm going to try to get ahold of a friend so we can go out and switch uppers and see what the deal is. I meant if that works, I'm not going to just settle for getting rid of the A5 and calling it a day. But that is a part of my troubleshooting plan going forward. Unfortunately I'll be lucky if I can get to the range this coming weekend... It may be 2 weeks before I can try anything. I appreciate all the help y'all have given me.
Let me make sure I understand you:
If you try the upper on a standard lower, and it works, you are not going to ditch the part on your rifle that is causing your upper not to run; because you believe that it is going to make the gun run better, even though you have no point of comparison?
Let me make sure I understand you:
If you try the upper on a standard lower, and it works, you are not going to ditch the part on your rifle that is causing your upper not to run; because you believe that it is going to make the gun run better, even though you have no point of comparison?
Pretty much, minus all the stuff about what I "believe". It's more like, this is the way I chose to build my gun, in theory it should work just fine, so I am going to make it work. Call it the engineer in me, but I'm not going to just drop the part because it's giving me a headache.
Not to mention, just because my upper will (hypothetically) cycle on another lower with a carbine RE, doesn't mean my upper will cycle on my lower with a carbine RE. Could find out something else is wrong with my lower. Or it might not fire at all and be a defective upper. Time will tell...
It's more like, this is the way I chose to build my gun, in theory it should work just fine, so I am going to make it work. Call it the engineer in me, but I'm not going to just drop the part because it's giving me a headache.Good luck with that, and I mean it in a honest way (non-:rolleyes:). I've learned things in this thread and I hope you do figure things out for the benefit of all of us gaining more understanding.
I bet the engineer in you would like to find the real cause of the problem. The best way to do this is to isolate the problem component(s), starting with upper/lower swaps with a couple of known good guns. One of the lowers should have a carbine RE and buffer. Keep in mind, both your upper and lower could be at fault. Until you do this, you're running in circles and anything that fixes the problem would be blind luck.
I hope this is a hobby gun for you, and you have the luxury of tinkering with it until it runs. If you want something that just plain works... you don't need to look far on this forum.
PA PATRIOT
08-13-13, 21:00
One last idea, if your buffer and spring are the correct version for your A5 I have to wonder if the anti tilt skids on the rear of the AA bolt may have something to do with the abnormal wear in the buffer tube, all that contact/friction inside the tube cant be helping things and maybe the two just aren't compatible?
That being said have fun with your "Project" gun and I hope it works out for you.
Plenty of people have given you advice on how to troubleshoot this. If you choose to ignore it there is nothing more we can do for you.
Pretty much, minus all the stuff about what I "believe". It's more like, this is the way I chose to build my gun, in theory it should work just fine, so I am going to make it work. Call it the engineer in me, but I'm not going to just drop the part because it's giving me a headache.
Not to mention, just because my upper will (hypothetically) cycle on another lower with a carbine RE, doesn't mean my upper will cycle on my lower with a carbine RE. Could find out something else is wrong with my lower. Or it might not fire at all and be a defective upper. Time will tell...
It's more like, this is the way I chose to build my gun, in theory it should work just fine, so I am going to make it work. Call it the engineer in me, but I'm not going to just drop the part because it's giving me a headache.
Well you see a little something new here each and every day. Always fascinating.
Ahh, the much awaited update....
First of all, some people may think I decided to ignore everyone's advice. That's not true. Many people gave good advice. A few threw in some anti-piston and anti-A5 advice, which I did choose to ignore. I wasn't going to just get rid of either one in order to "fix" this problem. I wouldn't call that fixing the problem, I'd call it building a new gun. My next new gun, which will have nothing to do with this gun, is going to be a DI AR with standard carbine RE chambered in 300BLK.
Anyway, there were 3 specific suggestions that I did choose follow.
1) Swap uppers/lowers with a functioning rifle.
2) Use some better ammo.
3) Lighten the buffer.
So the story goes like this...
1) Friend with functioning AR was completely willing to come to the range with me and swap parts. Unfortunately, other things kept getting in the way, so this never actually happened (yet).
2) Ordered 250 rounds of Lake City M855.
3) Ordered a standard carbine buffer and a kitchen scale. Upon receiving the scale, weighed my buffer, and it weighed 6.8oz (HAHAHAHA). Apparently the guy I ordered the Vltor parts from sent me the heaviest buffer Vltor makes (A5H4, all tungsten weights). Anyway, removed 2 of the tungsten weights and replaced with 2 steel weights from the carbine buffer, bringing the weight down to the 5.3oz it should have been as an A5H2.
Result:
Loaded 25 rounds of M855 into 30rd PMAG. All fired, all cycled no problem, bolt locked back on empty mag.
Loaded 30 rounds of the old Independence XM193 into various magazines. All fired, almost all ejected (some rather weakly, landing 6-12 inches away), 1 cycled the next round, none locked the bolt back on empty mag.
Loaded M855 into various magazines, 1 failed to feed, the rest fired and cycled fine.
Came home, did a quick inspection of the buffer tube, and didn't see any real damage other than some scratching all around on the inside... very minor looking.
So it sounds like it was, and still is, a buffer weight issue. I'm going to change the last tungsten weight to steel and it should function fine with all my ammo. If it needs to be lighter than that, I'll need to order a new A5H0 buffer, because the last tungsten weight in mine is the one with the spring attached (which I guess I could swap for steel one without a spring, but I have no more steel weights anyway).
Thanks for all the help guys!
Über heavy buffer.
Makes perfect sense.
Would definitely cause short stroking.
thopkins22
08-22-13, 23:43
The scratching is from the fact that the carrier isn't(and can't with a short stroke piston) operate the way it was designed to.
The gun as designed was an inline piston gun...the carrier ran nice and neat straight to the rear because the forces acting upon it were nicely centered inside of it.
Piston conversions change where the piston is. Instead of being centered inside of the carrier, it moves to the front of the gun and drives an op rod into the area where your bolt carrier key used to live(I realize you probably know this part.) When it's impacted off center, with the relatively short and small bearing surfaces, the carrier tilts as it's driven rearward into the receiver extension.
The good news is that to my knowledge this hasn't led to many serious issues, and the world is okay if not perfect. The bad news is that your inner engineer will now have to deal with something that's not working as designed, and the worse news is that it's due to a "fix." :p
BufordTJustice
08-23-13, 09:38
The scratching is from the fact that the carrier isn't(and can't with a short stroke piston) operate the way it was designed to.
The gun as designed was an inline piston gun...the carrier ran nice and neat straight to the rear because the forces acting upon it were nicely centered inside of it.
Piston conversions change where the piston is. Instead of being centered inside of the carrier, it moves to the front of the gun and drives an op rod into the area where your bolt carrier key used to live(I realize you probably know this part.) When it's impacted off center, with the relatively short and small bearing surfaces, the carrier tilts as it's driven rearward into the receiver extension.
The good news is that to my knowledge this hasn't led to many serious issues, and the world is okay if not perfect. The bad news is that your inner engineer will now have to deal with something that's not working as designed, and the worse news is that it's due to a "fix." :p
You've been reading Stoner's patent calling the AR an "inline piston", haven't you?
Stop it! ;)
For anybody who is curious, it's readable fo-free on Google patents.
thopkins22
08-23-13, 09:45
You've been reading Stoner's patent calling the AR an "inline piston", haven't you?
Stop it! ;)
For anybody who is curious, it's readable fo-free on Google patents.
Well...yes. But then it made sense when I thought about how the bolt and carrier interface and their position within the rifle.
Glad you got it working. So it turns out that the stock A5 system wasn't to blame... fancy that ;).
Mall_Ninja
08-24-13, 00:02
Glad you got it working. So it turns out that the stock A5 system wasn't to blame... fancy that ;).
Well, since the buffer was way to heavy, and it was a Vltor A5 buffer... ;)
Yeah, he thought it was stock A5H2 buffer when it was really the A5H4. That's like installing a H3 buffer thinking it's a H. The stock A5 buffer worked...
PA PATRIOT
08-26-13, 12:36
He's still having some issues that needs to be resolved before calling the rifle good, those failures to extract are a concern and the scoring inside and around the front of the buffer tube may not be carrier tilt but bad fit between the bolt and buffer tube.
Another update...
I opened the buffer back up and replaced one more tungsten weight with a steel one, bringing it down to 4.5oz with 1 tungsten and 3 steel weights. Took it to the range with the last 126 rounds of independence XM193 I had left. Loaded 25 in each type of magazine I had.
First up was a non-window M3 PMAG. The whole mag fed, fired, ejected, and fed again like clockwork.
Next up was a Lancer L5AWM. The first 2 fired, ejected, and fed, but after the 2nd round, the 3rd round stayed in the magazine. I kept trying, but the next 5 or so rounds would fire and eject, but the next round would never get picked up.
Then I tried the same with a window M3 PMAG, then with a USGI mag, with basically the same results. Occasionally I was have 2 or maybe even 3 fire back to back, but nothing consistant. Then there was the rare round getting jammed at an angle as it was being fed into the chamber.
I emptied about 10 rounds from one mag and loaded them into the original PMAG that fired all 25 rounds, but this time I had the same problem I was having with all the other mags.
So what do yall think?
1) Was it just a fluke that the first mag functioned flawlessly the first time?
2) Could the problem have something to do with the heat from firing the first 25 rounds? (I didn't fire them particularly fast or anything. In fact, took a short break half way to walk down range and back)
3) Is Independence XM193 really so weak that it still needs an even lighter buffer while Lake City M855 worked fine with the 5.3oz buffer?
Most likely from here I'm going to have to order a lighter buffer from VLTOR (or at least one of those special steel weights with the spring attached).
PA PATRIOT
09-18-13, 22:19
First I have to say that your buffer weight may still be to heavy and you still have not tried the recommended weight of a standard "H" or Carbine buffer, Second I have never seen IMI 5.56 being "Weak" and it usually runs a little hotter then standard 5.56
That said I still think you are having a issue between the A/A BCG and the VLTOR buffer tube, that scoring is abnormal for the small number of rounds fired and I would once again recommend shooting your upper on another standard AR lower and see what the results are.
So in closing I have to add that if your not going to follow the past suggestions that were already offered then the chances of correcting your current issue is slim. Rigid thinking is not the best route in working out the problems with your AR and just because you think it should work does not mean that it will.
I think one of two things should happen.
1. Follow the previous recommendations.
2. Get rid of the worthless piston upper and get a direct impingement one that will work.
For all you know there may actually be something wrong with the upper itself.
BufordTJustice
09-19-13, 04:36
I think one of two things should happen.
1. Follow the previous recommendations.
2. Get rid of the worthless piston upper and get a direct impingement one that will work.
For all you know there may actually be something wrong with the upper itself.
I have to admit.....that part in bold sounds familiar.
PA PATRIOT
09-19-13, 18:54
I think one of two things should happen.
1. Follow the previous recommendations.
2. Get rid of the worthless piston upper and get a direct impingement one that will work.
For all you know there may actually be something wrong with the upper itself.
"Worthless" maybe a bit over the top when assessing the A/A piston design as there have been many owners post positive comments and reported no issues what so ever with a A/A piston upper on the net.
That said I can speak from experience that my A/A mid length piston upper with a PSA lower, Colt mil-spec buffer tube and a 'H' or Carbine buffer has been just as reliable as my DI guns over the past few years. I don't have my log book handy but I think I have 4800rds fired without issue and while the round count may not be heavy compared to my DI guns the piston design has worked well for me.
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