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Posted: 2/6/2016 9:08:38 PM EDT
I was shooting a mixture of reman ammo from two online retailers today in a new Daniel Defense V9 LW that I cleaned two days ago. I was having very frequent FTF problems and I am trying to figure out if it's my gun or the ammo. I could hear the hammer drop, and I would have to mortar each ftf round out. I saved all those ftf rounds and would load them in a magazine to shoot again. Second time through the gun was about a 50/50 chance of ftf. I wasn't sure which ammo was in which mags (I loaded them prior to shooting), so I loaded a mag with only one particular brand of reman and loaded the V9. I had 21 out of 30 rounds ftf... I loaded that 21 back into the same mag, and put that in a four year old RRA Predator Pursuit. I have never ran reman ammo in that RRA and I have never had a single ftf. Probably 10 of those 21 ftf rounds failed in the RRA. My Daniel Defense runs new 55 gr vmax perfectly. This makes me think it's an ammo problem and not a gun problem. I have attached a picture of some of the ftf rounds. What do you guys think?
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If the bolt does not fully lock up (front of the carrier tight against the back of the barrel extension, then the back of the carrier (where the tip of the bolt protrudes out of it with the bolt fully locked up), will not allow the FP to reach the primer to allow enough FP tip pressure to ignite the primer.
To see this, just pull the B/C out of the rig, flip it key side down and pull the bolt all the way out, push the FP tight against the back of the carrier, and notice that the tip of the FP in not protuding out the face of the bolt. As for problem, first one to check is to pull the bolt off the carrier, then with just the carrier and key, dry fit it into the upper receiver to make sure that the sides of the key are not binding on the uppper receiver channel, and gas tube is correctly index with the key. Hence the B/C should move freely in the upper receiver, and the gas tube should enter smoothly into the key when the front of the carrier get about an inch from touching the face of the barrel extension. If the gas tube needs to be tweaked to align with the the key, then tweak the gas tube over the center of the barrel to index is correctly. Second problem could be that you suck at cleaning and CLP lubing the upper receiver bearing areas. Short verse here, start with a good copper solvent like Sweets copper solvent to remove all the copper fouling from the bore itself (does not require a lot of scrubbing), once you have that cleaned and dry, the break out a Ar-15 chamber brush to scrub the chamber by hand with CLP, then push the fouled CLP down the barrel from the bore to get both the chamber and bore dry. Even with the chamber and bore dry, enough CLP traces will still be on the chamber and bore for short term storage. As for the rest of the rifle, it cleaned first with CLP, the the fouled CLP removed, and new fresh CLP applied to the upper receiver bearing areas. Note the quick way to CLP lube the upper receiver bearing areas, just give the B/C a good shot of CLP inside and out, drop it wet into the upper, then empty cycle the B/C a few times to migrate the CLP on it, to the upper bearing areas. Lastly, it could just be that the ammo is out of spec, and why is not allowing the bolt to fully lock up in the first place. So if you weed out the two above first, and still notice that the bolt is not fully locking up with the ammo in question, then it ammo. Note, when the bolt does slam into the back of the carrier with the bolt not fully locked up, the force of the hammer against the back of the bolt most of the time will lock the bolt up instead (when you check afterwards with the round not fired). The problem, the force of the hammer to the FP with the bolt not locked home, is only enough to allow the bolt to lock up, but the force is lost doing this, and not enough FP pressure to ignite the primer once the bolt has locked up. I bring this up since one of the rounds may look like the FP dented it enough to ignite it, but it was not a full impact strike from the bolt being fully locked up in the first place. Note, when you have the bolt apart cleaning it, if you find a O ring around the extractor spring, remove it!!!!! Hence the problem could be that the extractor spring is already a Extra tension spring, and with the O ring added to add more extractor tension, the extractor can not slip over the case rim at loading smoothly to allow the bolt to lock up correctly in the first place. Barring that, , if the carrier is not binding up/gas tube is aligned with the carrier key, the suspect that your head space may be too tight on the rig if the ammo gauges out fine instead. Ammo test gauge, 
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Thanks a lot for the detailed response. It is not the first problem. I did exactly what you said and the carrier and key move through the upper freely and there is no bind up when the key indexes the gas tube.
I don't have any cleaning stuff with me right now, so I can't reclean and lube it at the moment. I'll have to do that tomorrow afternoon when I am back home and then go to the range next weekend to test again. |
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Quoted:
Thanks a lot for the detailed response. It is not the first problem. I did exactly what you said and the carrier and key move through the upper freely and there is no bind up when the key indexes the gas tube. I don't have any cleaning stuff with me right now, so I can't re-clean and lube it at the moment. I'll have to do that tomorrow afternoon when I am back home and then go to the range next weekend to test again. If you are going to shoot re-manufactured ammo, then an ammo test gauge will be something that you want to pick up and have with you. Hence, some of the brass may have been first fired in a over size chamber (cross wall dimensions) before being reloaded, and this can cause such cases to be over sized (even after been full sized) just above the web section of the case and not want to fit correctly in a tight cross wall chamber barrel. |
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Quoted:
If you are going to shoot re-manufactured ammo, then an ammo test gauge will be something that you want to pick up and have with you. Hence, some of the brass may have been first fired in a over size chamber (cross wall dimensions) before being reloaded, and this can cause such cases to be over sized (even after been full sized) just above the web section of the case and not want to fit correctly in a tight cross wall chamber barrel. Quoted:
Quoted:
Thanks a lot for the detailed response. It is not the first problem. I did exactly what you said and the carrier and key move through the upper freely and there is no bind up when the key indexes the gas tube. I don't have any cleaning stuff with me right now, so I can't re-clean and lube it at the moment. I'll have to do that tomorrow afternoon when I am back home and then go to the range next weekend to test again. If you are going to shoot re-manufactured ammo, then an ammo test gauge will be something that you want to pick up and have with you. Hence, some of the brass may have been first fired in a over size chamber (cross wall dimensions) before being reloaded, and this can cause such cases to be over sized (even after been full sized) just above the web section of the case and not want to fit correctly in a tight cross wall chamber barrel. Do they not do this at the factory before packaging them to sell? |
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Do they not do this at the factory before packaging them to sell?
Not always. That's why I don't shoot remanufactured unless I'm the one who made it. New ammo, as a general rule comes from the factory way shorter than SAAMI minimum dimensions. The shortest I have ever seen was .010" shorter than minimum SAAMI headspace. Once fired it stretches like crazy. When resized it will resist more or less depending too many factors for me to go into here. The bottom line is whoever resizes the brass has to constantly monitor headspace on the finished product to make sure it is at, or just under SAAMI minimum. Some people take their jobs seriously, some not so seriously. A momentary lapse can cause stuff to sneak through quality control. The number of times a case has been fired increases it's resistance to being resized (work hardening). Not enough resizing lube or too much lube can change headspace by more than .004" overall. Changing shell holder brands or dies will change headspace when resizing and will have to be adjusted for using quality tools. Hornady's Lock-N-Load cartridge headspace gage is the best value on the market and will allow you to check ammo at home. It works for wide variety of calibers so it's the most economical way to go. Measurements in .001" is easier for me to measure than calibrating my old eyes to any drop in gage. Your ammo must have at least .003" shorter headspace than the tightest semi-auto chamber in that caliber you own. You measure your fired brass headspace, at least 10 cases, and use the shortest reading -.003" as your "good to go" ammo. |
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Commercial Reloading Companies are loading thousands of rounds at a time at a very high rate of speed. You'd think that they would be checking the quality of their finished product at the very least, but QC costs time and money, so some companies do not do a lot of it.
Having to mortar unfired rounds out of the gun points to a serious problem. You claim to have cleaned it, so let's assume that you did, and know what you're doing. That would make the problem, either an extremely tight (machined too small in diameter chamber on the barrel, OR reloaded ammo that was not properly resized. This would also account for the FTF (failure to fire) problem. Tapping on the Forward Assist after each round is chambered may help if the bolt not being fully closed and locked is the problem (or may just jam the round harder). If the ammo is oversized (or the chamber undersized), and the round is not going into the chamber fully, then the bolt will not fully close, and rotate to lock. Unless the bolt is fully closed, the design of the AR-15 bolt and firing pin will not let the firing pin tip strike the primer on the round with enough force to fire it. Also when the bolt is not completely closed and locked up pulling the trigger result in the hammer hitting the firing pin, and the firing ping hitting the rear of the bolt and forcing the bolt more closed (jamming the round further into the chamber, instead of impacting on the primer). |
| Thanks for the replies. I don't know if it's worth my time to buy this ammo and have to check the sizing at home before shooting, rather than just buying factory new. I keep coming back to the fact that I can shoot factory new in the gun from the same manufacturer with no problems. In regards to cleaning- the gun is brand new and had maybe 100 rounds through it prior to that cleaning before shooting the other day. So let's say I didn't clean it at all, 100 rounds shouldn't dirty it enough to point to that being the problem, right? |
I haven't cleaned it since I shot this weekend and had all the problems. I just stuck a mag of reman from suspect brand in the V9 and charged it. Bolt is not fully closing on rounds. I can use the forward assist and sometimes get the bolt to close all the way. Even then, some of the rounds stick and I had to mortar one out in my bedroom, so I quit. I put those same rounds back in the same mag and did the same thing with my RRA and the same thing happened. Then I put a mag of new 55 gr vmax ammo in the V9 and was able to charge through rounds flawlessly. Here are some pics to show how dirty the V9 is. I don't think that's the problem.
RRA not fully closed on suspect ammo, granted this gun is much dirtier and needs lube. 
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