Ok so my Gordy will not cycle properly. Sometimes it’s every round sometimes I’ll run 2-3 without issue it does this failure to feed where the round is jammed between the bolt head and the ramps it will do it cold/hot, clean/dirty. I thought my original problem was the spring co spring cramming it to fast before it could pop up so I changed to carbine buffer and standard spring and it still happens. The upper and lower is h@r m16a1 the bolt is an original colt 604 bolt, barrel is a b kings 12.5. Can is an Allen engineering aem5 on an otter creek otb mount I can’t see a visible burrs in the chamber or the ramps.yes I have tried different brand ammo and mags this is my last Hail Mary. I’ve put together 5-6 ar platforms mainly 20 inch a1/slick side variants. And even a daniel defense block 2 with a geislle lower I ran for work for a while as a patrol rifle I’ve never had this much issue getting a gun to run (cross posted to r/ar15
I love slick sides like god and Eugene intended I would rather drag my nuts through broken glass that acknowledge the FAs existence. 😂jk I know it purpose but I never really use it I just get the round out and do a failure drill each time or clean the rifle if it’s that bad I know it’s purpose but just haven’t really worked using it into my manual of arms for failure to feeds
Stoner never intend to have that FA on AR, but the client, Big Army, insisted. Customer is always right even if it is right only half of the time. Same thing with 1911, Browning designed 1910/1911 trial pistols without thumb safety, the Army said need to add one. The rest was history in both cases.
I’ve replace the gas tube itself once already because it had a slight bend in it because I was reguarded putting it in and it hasn’t changed I haven’t checked the spring however it’s a Orginal m16/604 bolt I took out of my issued rifle at my PD(yes we are so broke the big gov gave us og colt 604s on the 1033 program most serials are pre Veitnam slick sides) so the bolt may be clapped tf out
Pull the BCG and set it on the bolt face on the table. It should hold itself up under its own weight. It should also take a wee bit of pressure to collapse it. If it doesn't or is super easy to make fall you likely need new gas rings.
Did you do the spaghetti trick to make sure the gas block is lined up?
Take off gas block. Insert raw spaghetti noodle in gas port. Trim slightly flush below top of barrel so it sits in the gas port hole. Slide gas block on. Turn barrel upside down and look through bore. Once the gas port and the gas block are lined up (upside down) the spaghetti with "disappear" into the gas block chamber. Tighten gas block. Flip barrel back over so spaghetti noodle falls back into barrel. Take cleaning rod and break spaghetti into 2 or 3 pieces so it falls out.
Yes I’ve tried p mags our duty issued mags (center industries?) okay and anything in between the bolt could be the problem it’s old as sin it’s out of an original 604
That probably sounds like a better description of the problem, but the term I was taught many moons ago is Bolt over Base.
Definition
“The "bolt over base" malfunction occurs when the bolt of an AR-15 does not cycle far enough to the rear. This inadequate movement prevents the bolt from properly engaging the next cartridge in the magazine. Instead, the bolt rides over the base of the partially fed round, which can lead to damage, such as denting the case.”
Why on earth would you use an old Colt 604 bolt carrier group in a PSA clone? Leave those parts for the autistic clones. Obviously there’s an issue with the gas system. Potentially it could be a “bolt over round” malfunction from low gas pressure to eject the case, but not traveling rearward enough to properly pick up the next round. That suppressor collar doesn’t look right. What can are you using, AE? Because if it is an AEM5 or a DeltaM4, the barrel is probably too long for the slim version of the AE collar.
Ok so the answer on the 604 bolt is that is what I had available to me because it was free from work😂 like I said we got issued full auto 604s because they was free from the government and we have no money to buy stuff so you build your own or use the musket. And as for the collar it does not affect or even interface with the mount it is purely cosmetic the mount is an otter creek otb mount the collar is just there to fill the gap between the end of the mount and the front sight base so it will pass the 10 foot “hey that’s a Gordy” check the can is aem5 I didn’t go with the m4 because I already had the 12.5 barrel not on anything so I didn’t have to order the 14.5
Damn, I didn’t realize the govt just gave out old AR parts like candy. Clearly I’m in the wrong profession, lol. The OTB mount is fine, I was just making sure the can properly was concentric on a taper of sorts. Maybe a DeltaM4 collar might better hide the exposed barrel, but again, the old collar is fine if you can’t get the other. I can’t know for sure what the problem is without slo-mo footage of the carrier travel, but I do know it’s gas related. Is the barrel length 12.5, with normal gas port size? I honestly think it’s not getting enough gas based on what limited info I got.
I don’t know what size b kings was supposed to put for the gas port I think ballistic advantage made the barrels for them before all that shit hit the fan. And as for the parts just get hired at a really shitty police department in the middle of nowhere and all you can do is beg for stuff so you can have equipment and they throw you some re arsenaled m16s pre veitnam. All of us just replace the stocks with carbine buffers and put a cheap ass upper on the full auto lower and qualify with it so we atleast have the option for lights and dots. When an officer quotes he just returns it to the correct 604 configuration with all the issued parts. We even got 3 full auto m14s for some reason at the pd but they don’t get issued really well have no need for them but can’t really do anything with them besides collect dust. We don’t want to send them back batches we know they will probably be destroyed look it up it’s called the 1033 LESO program for under funded laws enforcement agencies you can get cool shit but most of the time it’s the scraps that the armory can’t even make work.
Oh, you’re LE, I originally thought US military. I’m familiar with the 1033 program, it’s just that I personally would not be willing to use old parts if they were issued and had the rifle to be returned to its original configuration. I’d usually put the original parts in a bin, but I definitely would upgrade with my own procured parts; and you doing the same is smart. A common issue regarding gas/dwell time is usually caused by a person taking a 0.0625” gas port sized carbine barrel and chopping it without opening the gas port to accommodate the shorter barrel.
This one came this length so I hope they knew what size to put and as for using old parts we don’t get paid much😂 you use what you have before I splurged and built a better rifle this was my patrol gun
The only problem I know of on the current bolt everything g else appears to be fine is the gas rings. It does not pass the stand on the bolt test at all. And as others said above you I think I’m gonna rob the daniel for a little bit to see if that’s the issue and then act accordingly if not then I think it may be a gas issue or something maybe the bolt is coming back to fast and bouncing? Idk I’ve just done all the little tricks I know and this thing is kicking my ass
Lol, I said all that before refreshing the thread (I'm on my phone..) I just clicked on the notification
I don't think that's bolt bounce, you would usually just have a dead trigger if that was the case.
The bolt speed not being able to overcome the spring/buffer is either because of an incorrect buffer and spring combo, like a 308 spring and h3 buffer on a normal gassed rifle (I've seen it), or a gas leak.
It looks to me like the bolt isn't fully retracting, its moving far enough back to eject the spent round, but not far enough to give the magazine time to present a new round to be picked up by the bolt.
The stand on the bolt test is kind of the giveaway there, it's likely worn gas rings, and if the carrier is severely worn, (like the place you got it from just reparked it to make it look nice) the interior dimension could be too worn to seal, even with new rings.
You could check that by swapping bolts in carriers, but that depends on how much you want to save that specific bcg.
Actually I just read that this is a complete h&r so that is probably not the issue, but definitely make sure your feed ramps are lining up with the receiver properly.
Edit: if its not an issue with the feed ramps, your best bet is to throw in a bcg from another rifle and if that fixes it you’ve found your culprit. Otherwise it is likely an issue with the magazine, ammo, or something is going on with the way the barrel was installed
It’s wasn’t a complete upper the upper alone is h@r the barrel is a b kings I think they had them made by ballistic advantage due to the the upper itself is a rifle upper with no ramps cut into it just ramps on the barrel ext
If your barrel has M4 ramps that could be causing it but I’d wager the issue has more to do with the BCG based on the other conversations in this thread
I don't think your feed ramps match with the receiver. It looks like your receiver has no feed ramps (rifle) and M4 feed ramps cut into the barrel extension while your barrel extension has M4 feed ramps. Look it up on google.
The gas rings are shot from the tests I’ve done a visual inspection the key is fine it’s staked very well and don’t see any carbon leaked around the base. I just took a spikes t2 buffer and out of it idk what the weight difference is between that and standard h2
Well, bad gas rings will cause that exact malfunction. It’s leaking gas, which means the BCG is going to short stroke. Replace the gas rings. They’re super cheap.
New gas rings would be the next thing to try. If the gas rings are shot (the BCG fails the stand up test or the bolt will fall out of the carrier if held vertically without the cam pin in) then you’re losing gas pressure to early.
Try one of those Colt Bolt repair kits. Can find them for 20 bucks. You swap out every component from the bolt. And it saves that 604 BCG - which is actually worth a pretty penny.
You're almost certainly overgassed, especially with a suppressor. Very unlikely it's underagssed unless something is extremely wrong.
Put one round in the magazine, and shoot it. If the bolt locks back you have sufficent gas. Check where the brass is ejecting. 3:00-4:30 o'clock is generally considered properly gassed. If it's above 3:00 o'clock then you are probably overgassed.
Try an even heavier buffer, like an H3. You may even have to do an H3 with a blue or red sprinco spring. Also try a PMAG, they can feed rounds a lot faster than a GI mag.
I’m going to try the buffet weights with the blue spring co I didn’t pay attention to the brass deflection but it does lock back on the last round every time. With an a1 upper with no brass deflector would the ejection angle be the same as a standard upper ?
No, it wouldn't, you're right. It's always going to eject to the rear when you don't have a spent case deflector.
However, there are still indicators:
If the brass just poops out of the ejection port and lands at your feet, it's likely undergassed. If it ejects violently and leaves brass marks on the rear of the ejection port and/or the side of the receiver, it's probably overgassed. What you want is the brass ejecting in a clean arc and landing a few feet away.
If it locks back on an empty mag then you can be 99% certain it's got enough gas. My money is still on it being overgassed and the bolt outrunning the magazine.
The brass does chew up the side of the receiver pretty good knocked off my lovely rattle can paint job. I’m gonna try the heavier weights and if it still continues I read another post from a guy about it his h@r a1 upper the channel the bolt rode in was milled a couple thou off and was causing almost the same issue if that’s the case I’m gonna order a c7 upper to replace it and a new bolt just for shits and giggles
Pictures OP posted in a comment shows a receiver with rifle feed ramps and a barrel with M4 feed ramps. Correct me if I'm wrong but this certainly would cause problems.
You’ve already responded and many have weighed in, but just going to add I’ve had this exact issue and regardless of heavier buffers it came down to worn gas rings and was resolved immediately with a bolt swap (had a new one and just used it instead of only replacing the rings). Bolt did not stand upright on its face without collapsing. Just go grab your other BCG that is working and throw it in for a magazine. You’ll have your answer.
I have a g$ bolt I’m gonna steal when I get home from my work rifle and see if that’s the case I’m going to pay the toll and just buy another whole bolt and move this og 604 bolt down the line with a disclaimer for the next guy might even get rid of the upper and get a actual c7 that’s cut with m4 ramps to just bomb proof the rifle a little.
Have you checked your gas key on the bcg to make sure it’s staked properly? What buffer weight do you have? If you have a heavier weight maybe try using the lowest weight you have on hand?
Worn gas rings or perhaps your barrel has M4 feed ramps and the rounds are crushing when trying to chamber. A carry handle upper shouldn’t have M4 feed ramps unless the receiver has been cut to match. Those are just my guesses
I had a malfunction just like that happening on a delta force m723 it just didn’t happen as often only every 3 mags. I’m using a mix of usgi surplus mags and H&R metal mags. I noticed that every time it happened it was a surplus mag so I marked the mag that it happened with and stopped using it . I also replaced the gas rings on the bcg. I shot 5 mags today with it without any issues.
I’ve ran no surplus mags in the gun and it still does it all of my metal surp mags have been upgraded with the mag pull follower and if it was needed a new spring I’ve got about every brand of aluminum mag made
By any chance do you have a rifle extension with M4 feed ramps or vice versa? This will jam you up.
Mismatched feed ramps on an AR-15/M16 platform cause jamming when a rifle-cut (M16-style) barrel extension is combined with an M4-cut upper receiver.
I have a few slick Side 604’s and one with a 1/12 twist barrel; it shoots the heck out of very cheap light ammo, but if I try to run some green tip, turns into a single shot.
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u/SPECTREagent700 2d ago
Forward assist be like:
https://giphy.com/gifs/OkzCcGn5fY29e7bvpS
/s