Canajun 1 Posted October 17, 2013 Report Share Posted October 17, 2013 I was shredding some paper today with my new 10 round mags and after 60 or so rounds without any issues, the gun started failing to cock after it successfully ejected a round. The next round chambered as it should, but obviously, I couldn't shoot it, without manually pulling back on the charging handle. I'm thinking it is probably a cleaning issue, since I haven't had the bolt out and cleaned it yet. The gun has a Tac-12 lower. How do I get the upper and lower apart? Is there a bolt under the buffer tube, like where it would be on a stock gun? Thanks! Quote Link to post Share on other sites
Hunter308 6 Posted October 17, 2013 Report Share Posted October 17, 2013 Take your pick. Choose one, choose all. Quote Link to post Share on other sites
Canajun 1 Posted October 17, 2013 Author Report Share Posted October 17, 2013 Right... but these are all stock guns. I did a search, and Firebird does not have disassembly instructions anywhere. Quote Link to post Share on other sites
Rebel Katt 6 Posted October 18, 2013 Report Share Posted October 18, 2013 Yes, the screw is accessible by removing the buffer tube. Are you familiar with the rest of the process? RK Quote Link to post Share on other sites
Canajun 1 Posted October 18, 2013 Author Report Share Posted October 18, 2013 Thanks. Yep. I've had pretty much everything else apart. Looks like I'm buying an AR15 wrench tomorrow. I'm thinking there's something in the firing pin mechanism inside the bolt that is gummed up with gunk to cause that malfunction. It was running flawlessly, then the same deal every pop. The gun cocks manually just fine, and fires every time. Maybe I'll take the bolt apart and clean and lube everything tonight. Then try it again in the morningl. Quote Link to post Share on other sites
Armand Willis 4 Posted October 18, 2013 Report Share Posted October 18, 2013 (edited) Another variable could be the brand of ammo being shot, evidently. Edited October 18, 2013 by The Shop Monkey Quote Link to post Share on other sites
Canajun 1 Posted October 18, 2013 Author Report Share Posted October 18, 2013 No, I was using Winchester and Remington loads that I'd never had a problem with before. After looking at it, it seems that something in the hammer mechanism is gunked up enough to stick it just long enough to keep it from locking back in the microsecond that the bolt slides back and forth. If it's ejecting the shell, the bolt is sliding twice as far back as is necessary to cock the hammer. I'll have to take it apart and give it a good cleaning and go from there. Quote Link to post Share on other sites
james lambert 3,059 Posted October 19, 2013 Report Share Posted October 19, 2013 We have had two disconecters break It seems with the last AR15 triggers we used, the rear of the disco can contact the slot during operation causing a failure. If it turns out that this is your problem, contact me and I will send you a new one. Jim Quote Link to post Share on other sites
Canajun 1 Posted October 21, 2013 Author Report Share Posted October 21, 2013 (edited) OK... I figured it out. The hook on the hammer that interlocks with the hook on the trigger mechanism (which, I believe is to keep it from going full auto) is worn, and there was a burr resulting that kept the hammer locked back, even though the trigger was released, until the bolt was pulled back. See pics. I filed off the burr, and lubricated it. https://dl.dropboxusercontent.com/u/8965737/IMG_1413.JPG https://dl.dropboxusercontent.com/u/8965737/IMG_1415.JPG Also, I noticed that the bolt is catching on the inside of the upper receiver. If I hold the receiver upside down, and push the bolt back gently, I can actually get it to grab hard so that it won't move. Note the worn spot in front of the bolt, on the top side of the indentation. https://dl.dropboxusercontent.com/u/8965737/IMG_1419.JPG I haven't done anything with this issue yet. I suspect this is why it still only 50-50 on cycling light loads. Should I grind this spot down? That seems the safer option to just letting it smack if the bolt jumps up any inside the receiver. Anyway, the hammer/ trigger issue seems to have fixed the more pressing issue... this is with Winchester Universal loads... http://youtu.be/sIL0fVrScs0 Edited October 21, 2013 by Canajun Quote Link to post Share on other sites
Anubis 38 Posted October 21, 2013 Report Share Posted October 21, 2013 OK... I figured it out. The hook on the hammer that interlocks with the hook on the trigger mechanism (which, I believe is to keep it from going full auto) is worn, and there was a burr resulting that kept the hammer locked back, even though the trigger was released, until the bolt was pulled back. See pics. I filed off the burr, and lubricated it. https://dl.dropboxusercontent.com/u/8965737/IMG_1413.JPG https://dl.dropboxusercontent.com/u/8965737/IMG_1415.JPG How many rounds through the gun? As you mentioned, the secondary sear is what prevents the hammer from following the bolt foward when it chambers a new round. As you release the trigger, the disconnector releases the hammer and it catches on the primary sear surface of the trigger. If the wear on your hammer continues it can get to the point where the secondary sear no longer functions, and there is a possibility of your gun either going full auto or, more likely, the hammer just following and preventing the gun from functioning. As far as your bolt catching in the rear of the upper, in some of the uppers the Turks did not complete the clearance boring for the bolt. In all liklihood this is catching on the right rear corner of the bolt against that incomplete clearance. You can fix that with a dremel, just remove a small amount of material at a time and check for fit. Quote Link to post Share on other sites
Canajun 1 Posted October 21, 2013 Author Report Share Posted October 21, 2013 I bought the gun from Joe Dirt, on this forum. He said he only put 50 through it. This is consistent with his posts. I put less than, but close to 200 through it. Seems like a lot of wear for 250 rounds. I have a Barrett REC7, and a Colt Match Target with several hundred... well, probably thousands through them, and neither one of them have any like issues. I will set to finding my dremel tool later today and see if I can get a box of Rio's run through it after that. Thanks! The next fix is the safety selector switch. It's all flopping around and loose. I went to whack a goose yesterday and it had jumped the bump stops on the lower and was pointing backward... I straightened it out and still got the goose. Any ideas on that one? Quote Link to post Share on other sites
Anubis 38 Posted October 21, 2013 Report Share Posted October 21, 2013 (edited) As far as the wear on the hammer goes, there was a side by side comparison done on this forum. Unfortunately the discussion on that thread devolved into some pretty heated comments. The owner of the gun was adamant that it had only had 80 rounds fired. We observed about half of the wear you show on your hammer on the example we had. We did a Rockwell test on the hammer and it wasn't even close to the hardness that is absolutely required for these components. Your original hammer and disconnector are manufactured from an appropriate material and have the correct heat treat, they're just not 922r compliant. You could reinstall them and resolve that issue. Now for the safety, is it the factory safety? Also what detent are you using, the factory ball detent, the factory cap and spring, or the detent that's supplied with the Firebird lower? Edited October 21, 2013 by Anubis Quote Link to post Share on other sites
Canajun 1 Posted October 21, 2013 Author Report Share Posted October 21, 2013 It looks like the factory one... The powder coat is different. Quote Link to post Share on other sites
Anubis 38 Posted October 22, 2013 Report Share Posted October 22, 2013 If the safety detent is a ball detent instead of the spring and cap system this can be caused by it backing off a little. The tension from the detent is what holds the safety in place. The Firebird ambi safetys can't walk like this due to the levers on either side retaining the whole assembly in place, but the screws can come loose on the levers. I would suggest using blue locktite on them. In any case with any safety that uses the ball detent instead of the spring and cap system it can back off and cause the safety to rotate freely. Quote Link to post Share on other sites
Canajun 1 Posted October 31, 2013 Author Report Share Posted October 31, 2013 Thanks for the safety detent, Anubis! Got it in the mail today. Works like a charm. Now it feels like one of my Barrett's! Good, solid click, no slack in the safety lever, anymore! Quote Link to post Share on other sites
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