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Posted: 2/11/2007 12:22:16 PM EDT
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THE SETUP: POF P-416 16" upper with M4 hand guards. RRA 2-stage trigger. Enidine carbine buffer. 2 old 30rd USGI mags, 2 new 10rd C-Products mags [All with grey Magpul followers] Everything lubed up properly. AMMO: Remington UMC 55gr Wolf 55gr FMJ and 62gr HP American Eagle 55gr Various 5.56 (don't remember anymore) THE PROBLEMS ENCOUNTERED: -Rounds gets jammed on the feed ramps. The bullet snags on the lug. Also happens when bolt is released from the held-back position when chambering the first round of the magazine. -Bolt fails to extract rounds from the magazines. -When last round is fired, the bolt is usually held back on the follower rather than the bolt catch. The bolt catches on the follower. -Sometimes the round doesn't get fully chambered. These problems don't ALWAYS happen, but depending on the ammo used and the magazine, the frequency of it happening changes. It has happened with all of the ammo and magazine combinations I've used. I can usually expect at least 1 problem with each magazine. I tend to get more issues with 5.56 than the .223, but that's more of a guess than anything I've documented. On all 3 of the shooting trips I've used the rifle, I've had some problems. The last trip got cut short because the Wolf 62gr had constant FTE's (stuck in the chamber) involving very hard pulling on the charging handle. The trip ended when the rim from the case ripped off and I had no way to dislodge it. Less than 10 rounds of it fired before it happened. The first thing I would like to rule out are the magazines, but I don't have any more other than those to test. I'll try to borrow someone's next time. My next guesses are the Enidine buffer or something with the POF upper. I hope I've covered everything needed for some good troubleshooting. Thoughts? |
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Conditions of the feed ramps, are they smooth, or mill chattered? Does the bolt move freely in the carrier without the cam? The mags are low feeding; this could be due to the mags (old, worn out, and 10 rounders never feed right until tweaked), or due to the action not cycling strongly. As for the Wolf ammo stuck in the chamber, could be chamber conditions such as new rougher plating, fouling, or even just a chamber on the tighter side. Now to make you life simple, get POF on the phone and let them know that you are having problems. They are good about resolving them, even if it means that you will have to send the rifle back to them for a few quick tweaks. |
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I have the exact same problem with my rifle. Failure to feed reliably. It is the DSA dszm4gtc carbine that uses the same Patriot upper as you have. Some of it was the new style teflon mag, the case shoulder would catch on the front of the mag when I would hand strip a round from the mag with a pen. I filed this down and it helped the overall feed, but it still hangs with a round half up the ramp sometimes. I did an inspection of the feed-ramps a while back and noticed some horizontal tooling marks that are right where the bullet tip contacts the bottom of the feed-ramp groove. It's hard to see because Patriot hard chromes the entire barrel/chamber face including the ramps. Shine a light up through the mag-well onto the ramps while looking at them from the back of the upper. I did contact Patriot about this and they said to strip down the upper of all accessories and send it in and they will check it over and polish the ramps. I'm lazy and have not done this yet, plus I'm thinking of asking if I can upgrade to the new chromed upper they have (inside of the upper has a chrome-like finish, very slick). I hear those are nice with very little friction. *update* The silicone nickel coating is not something that can be applied (I didn't think it could be), I would need a new upper and it sounds like it has to be special fit or something.. The rep said it would be atleast $600 minimum to get into one of those, it's an option on a new build. I also tried an old colt 5 round mag I had lying around (one of the 20 rounders colt blocked and pinned when the ban came down) and it fed much more reliably than the defense solutions mag that shipped with the rifle. It did still have a few failures when manually cycling the rifle so I contacted Patriot and sent my barrel back on Thursday the 22nd to have the ramps inspected and polished. No idea on turnaround time but I'll post the results here. Other than the ramp issue I love the rifle and new gas system. Seems to reduce recoil a great deal, much faster follow up shots. |
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