Posted: 9/28/2015 4:48:47 PM EDT
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Hi, I just built a new RRA AR15 and am experiencing some failure to feeds. It's a CAR A4, basically. All RRA Parts. It doesn't FTF all the time, and has happened with 5 different, brand new USGI Brownells magazines with tan followers. Throughout the course of fire, the casings were ejecting at the 1:30 pretty consistently so I'm thinking it's overgassed. Ammo was Wolf Gold 55gr .223 FMJ, so nothing really hot. It seemed to only happen after I expended nearly 300 rounds, and the rifle was getting nice and hot. The hotter it got, the more frequently it happened. Any suggestions for a DIY fix? I'm using a standard buffer weight, and am considering buying an H or H2, but dunno which would give the best performance. I'm also willing to switch to a full auto carrier, but I need more than that. I tried a FA carrier at the range and had the same issue after 20 rounds through one mag. |
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Quoted: I would start with further testing using different ammo to see if it is confined to the Wolf Gold or is repeatable with other loads as well. Use the same magazines, buffer, and semi carrier so you're only changing the single variable. Thanks.. Steve/RRA. I tried with PMC X-Tac, which is hotter ammo. While I did not have the issue, I did not shoot enough to really have a chance to find a malfunction as it didnt happen ALL the time, only when the gun got hot. I can say though that I noticed the ejection was getting closer to the 12 o'clock pattern and there was a bit more recoil. What gas port size does RRA use for their 16" Carbine-gas barrels? I can pop off the FSB later and measure it up. Also, I counted my ammo... I ran 445/460 rounds of Wolf Gold, those 15 being the malfunctions, with multiple brand new mags. |
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How long is it taking you to get it hot enough to have the problem occur? I know you said 300 rounds, give or take, but how rapidly are you shooting them to get it "hot"? mag dumps, a lot of rounds over a prolonged range time, or something in between?
Did you clean the rifle (in particular the chamber) between having the failures and trying the PMC? Ultimately, the goal would be to shoot enough of some other ammo to duplicate the problem (or get past the point where It started to act up with the Wolf), but I really don't want you to go to that expense if we can figure out some other potential cause than the ammo/ammo related. Steve/RRA |
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Quoted: How long is it taking you to get it hot enough to have the problem occur? I know you said 300 rounds, give or take, but how rapidly are you shooting them to get it "hot"? mag dumps, a lot of rounds over a prolonged range time, or something in between? Did you clean the rifle (in particular the chamber) between having the failures and trying the PMC? Ultimately, the goal would be to shoot enough of some other ammo to duplicate the problem (or get past the point where It started to act up with the Wolf), but I really don't want you to go to that expense if we can figure out some other potential cause than the ammo/ammo related. Steve/RRA I'd say 2 or 3 seconds so before firing the next round. But I had 10, 30 round mags loaded up ready to go, so I was barely down in time between reloads. The gas tube/handguards had some smoke coming up from them and it didn't start malfunctioning until maybe 5 to 6 consecutive magazines. The range I go to prohibits mag dumping. I did not clean the chamber between swapping ammo. If it helps, I can provide pictures of the brass later tonight to see if there's any scrapes or gouges. For the most part, the brass was still shiney with no "frost" to it as well. Like I mentioned, just based on ejection patterns I am feeling it's overgassed, but just odd it happened after the rifle was heated up and not off the bat. When the malfunction happened, the initial recoil felt normal, just no slam forward like when it chambers a round. I wish I had more ammo to shoot of a different brand, but Wolf Gold is more affordable than others, and better than their Russian bi-metal steel cased. Let me know what other info I can provide to help. |
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When you bring up your ejection position, what reference are you using. Normally 12 o'clock would be directly forward, and three o'clock is directly to the side. Typically, our 223/5.56 ejection pattern will be between 2 and 4 o'clock, primarily dependent on bolt velocity, which itself is a generally a function of the round fired.
Over gassed and under gassed are overused terms in that the gas port diameter is the same within a class of barrels, but I can fire different ammo from five otherwise identical barrels and get different muzzle energy, muzzle velocities, bolt velocities, ejection patterns dwell times, etc..from each of them, with the only difference being the ammo fired through them. That's why I've been asking about the ammo used and your perceptions of what's going on and when. That you're seeing and feeling a difference between the Wolf and PMC loads is an indicator of this... Steve/RRA |
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Quoted: When you bring up your ejection position, what reference are you using. Normally 12 o'clock would be directly forward, and three o'clock is directly to the side. Typically, our 223/5.56 ejection pattern will be between 2 and 4 o'clock, primarily dependent on bolt velocity, which itself is a generally a function of the round fired. Over gassed and under gassed are overused terms in that the gas port diameter is the same within a class of barrels, but I can fire different ammo from five otherwise identical barrels and get different muzzle energy, muzzle velocities, bolt velocities, ejection patterns dwell times, etc..from each of them, with the only difference being the ammo fired through them. That's why I've been asking about the ammo used and your perceptions of what's going on and when. That you're seeing and feeling a difference between the Wolf and PMC loads is an indicator of this... Steve/RRA I've been using the chart below as reference. So yes, 12 o clock would be directly forward as you mentioned. It'll be a few weeks before I hit the range again, and can buy enough ammo to test different brands to find out whether or not it's the ammo or something else. I'll try to get my hands on some PMC X-Tac, Fed. AE., LC 193, and Wolf steel cased military classic. Is there a brand of ammo RRA recommends for optimal performance? I was hoping to stock up on Wolf Gold due to the lower cost but if it will cost me only $20 more to get something much more reliable, I'll do that.  |
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We have a generic statement on ammo: Brass cased ammunition in a loading appropriate to the chamber and bore of the rifle it is to be fired through, factory-loaded by a reputable domestic manufacturer.
I like to use spec M193 or M855 5.56mm ball ammo....they're known commodities and have to make specific velocities to be spec. Steve/RRA |
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Quoted: We have a generic statement on ammo: Brass cased ammunition in a loading appropriate to the chamber and bore of the rifle it is to be fired through, factory-loaded by a reputable domestic manufacturer. I like to use spec M193 or M855 5.56mm ball ammo....they're known commodities and have to make specific velocities to be spec. Steve/RRA Thanks. Next time I buy ammo I'll dump a couple hundred bucks on various domestic production ammo to see if it fixes the problem. |
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I wish you didn't have to go to that extreme, but when it's taking a couple hundred rounds for it to act up....
For testing, try to duplicate your rate of fire. For general use, I would slow it down. The sustained rate of fire for an M4 is only 12 rounds per minute, and you're at 20-30 if you're cranking out rounds every two to three seconds. Steve/RRA |
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Quoted: I wish you didn't have to go to that extreme, but when it's taking a couple hundred rounds for it to act up.... For testing, try to duplicate your rate of fire. For general use, I would slow it down. The sustained rate of fire for an M4 is only 12 rounds per minute, and you're at 20-30 if you're cranking out rounds every two to three seconds. Steve/RRA Sorry, I find the rate of fire comment to be a little hard to believe. So you're saying basically if I want a more reliable rifle, I need to not shoot as fast? I don't think I was shooting anything excessive. The only time I've shot anything excessive was torture testing a new AK74 build, with 1110 rounds without a single malfunction. And that was over the course of 5 hours. Over the course of 4 hours this upper couldn't handle 460 rounds without 15 malfunctions. I guess I had my expectations up too high for RRA. Anyway, enough with that. I'll go and spend more money to test to see if your product is defective or if it's just my ammo. How slow do you suggest I shoot? |
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If you're at the point where your handguards are smoking, your rifle just may be getting a bit hot, and that heat may be contributing to the issue you're having. Nothing more or less intended with that statement.
I don't know anything about the components you bought from RRA and assembled yourself. I assume that everything was assembled properly, the necessary safety checks were made, and all is well in that regard. At that point, you requested help in identifying the cause of an issue that you are having. I've offered ammo and rate of fire (resulting in a heating issue which, as mentioned, may be contributory), but we won't know without further testing. I'm happy to work with you on this, but the insinuation that a collection of components that you assembled add up to a defective RRA product is out of line and needed to be addr3essed. Steve/RRA |
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Quoted: If you're at the point where your handguards are smoking, your rifle just may be getting a bit hot, and that heat may be contributing to the issue you're having. Nothing more or less intended with that statement. I don't know anything about the components you bought from RRA and assembled yourself. I assume that everything was assembled properly, the necessary safety checks were made, and all is well in that regard. At that point, you requested help in identifying the cause of an issue that you are having. I've offered ammo and rate of fire (resulting in a heating issue which, as mentioned, may be contributory), but we won't know without further testing. I'm happy to work with you on this, but the insinuation that a collection of components that you assembled add up to a defective RRA product is out of line and needed to be addr3essed. Steve/RRA Sorry if I'm seeming out of line or insinuating. I'm going to try new ammo, an H2 Buffer (will remove weights to go to H Buffer if needed) and a FA Carrier. I'll keep trying to get this to work. My AK just had me spoiled is all  |
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Quoted: To isolate what is causing you problem, please only make one change at a time. The heavier buffer and '16 carrier will slow the cyclic rate, which may or may not help. Thanks. Steve/RRA |