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Posted: 1/30/2011 8:06:50 PM EDT
| Well I finally got my 9mm DDLES lower along with a RRA upper together. I am using 32rd metalform mags, with a ramped RRA bolt. I originally had a RRA LPK with 9mm hammer, but I bought a regular 223 hammer off the EE to used with the ramped bolt. After putting it together using the 9mm buffer it would double and triple and the hammer would end up in the fired position the casings were ejecting at about the 1oclock position. I figured the trigger and hammer were not working properly since it was letting it drop and fire multiple times. I changed out the FCG with a bill springfield FCG, and it would still double and leave the hammer in the fired position. I changed out the buffer to a PWS T2 that I have and it pretty much works flawlessly unless I fire very rapidly and it will occasionally not completely eject the shell all the way and try to bring the next round into battery. The bolt hold open works and the casings eject at about the 2-3 oclock position. Any thing else I should try to get it to runn 100% when fired rapidly? Do I need to use a heavy buffer, or can I try a lighter buffer? Thanks for your help, and I hope my text above is understandable.. |
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Some of the 9mm AR's that I have seen double/triple were from a firing pin issue (no spring or wrong spring) or a disconnector issue (gun wouldn't pass function check, but owner fired it anyway).
Did you function check your gun before live fire? Did it pass? If it passes, it could be that your ramped bolt isn't fully resetting your hammer every time under live fire and allowing it to follow, which could lead to unwanted doubles/triples. Low powered ammo and a heavy buffer could also simulate this - a short-stroking of sorts, that is just enough to cycle the action and eject rounds, but not enough to fully reset the trigger every time. Short stroking could also explain the ejection issues. You may want to check the ejector position to ensure it is proper. Probably wouldn't hurt to check the extractor also - RRA sometimes uses a crappy roll pin to hold it in place and it can allow the extractor to clock slightly out of position - best bet is to replace the roll pin with a longer tension pin from the hardware store. |
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Quoted:
Some of the 9mm AR's that I have seen double/triple were from a firing pin issue (no spring or wrong spring) or a disconnector issue (gun wouldn't pass function check, but owner fired it anyway). Did you function check your gun before live fire? Did it pass? If it passes, it could be that your ramped bolt isn't fully resetting your hammer every time under live fire and allowing it to follow, which could lead to unwanted doubles/triples. Low powered ammo and a heavy buffer could also simulate this - a short-stroking of sorts, that is just enough to cycle the action and eject rounds, but not enough to fully reset the trigger every time. Short stroking could also explain the ejection issues. You may want to check the ejector position to ensure it is proper. Probably wouldn't hurt to check the extractor also - RRA sometimes uses a crappy roll pin to hold it in place and it can allow the extractor to clock slightly out of position - best bet is to replace the roll pin with a longer tension pin from the hardware store. Thanks for this info I will check those things, and let you know what I come up with. Thanks again..Wesley |
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Function checked my 9mm properly today, and when i hold the trigger down and cock the hammer back if i let off of the trigger slowly it will drop the hammer... Gonna try a different FCG tomorrow..
My rifle is ejecting the casings at about the 2-3 oclock position.. Where would be the optimal position for them to eject? What should I try to possibly fix that problem? The ammunition that I am using is CCI Blazer 115 grain. I will be picking up a box of 9mm from Academy in the morning to see if that changes anything.. Any suggestions on the brand ammo I should try? |
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Quoted:
Questions about the hammer, both the first "regular 223 hammer" and the one in the FCG you replaced it with. Is it "rounded" or "notched?" A notched hammer will definitely have problems with a ramped 9mm bolt; the typical ramping angle is intended to mimic the ramp on a standard M16 bolt carrier, and works best with a hammer that has the same face profile as an M16 hammer-i.e. the "rounded" AR hammer.
but I bought a regular 223 hammer off the EE to used with the ramped bolt. Comparison of notched and rounded AR hammers,  ––––
Rounded hammer from DPMS via PK Firearms––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––-Notched hammer from CCT Firearms The rounded hammer should work with any AR configuration-9mm, .22, 5.56mm, 6.8mm, etc... Notched hammers choke on .22s and 9mms. And don't even think about a "9mm hammer" working with anything but an UNramped 9mm bolt. 
From Ranier Arms. Edit: note that "submit" is NOT "preview." Mind which button you click! Had to fix some tags... |
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Quoted:
Function checked my 9mm properly today, and when i hold the trigger down and cock the hammer back if i let off of the trigger slowly it will drop the hammer... Gonna try a different FCG tomorrow.. This is a very important thing to do when building up any gun or swapping parts around. It only takes a few seconds to do a function check. Another thing that many find beneficial is the old load , fire 1 - load 2, fire 2 - load 3, fire 3 test when first live firing a new build. Make sure the gun passes each test before moving on to fully loaded mags so you don't risk a 30+ round unexpected full auto runaway... Quoted:
My rifle is ejecting the casings at about the 2-3 oclock position.. Where would be the optimal position for them to eject? What should I try to possibly fix that problem? The ammunition that I am using is CCI Blazer 115 grain. I will be picking up a box of 9mm from Academy in the morning to see if that changes anything.. Any suggestions on the brand ammo I should try? I would say that your ejection is just fine - 9mm ARs tend to throw brass in the 1-3 o'clock position. I would not change anything. |
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Ok I think I got it pretty much figured out. I put a Daniels Defense FCG and it passed function test. The only thing is it is a notched hammer, which some people say will not work. It fires appropriately, and only had a couple failure to eject all the way out, and that was out of 200 rounds that I will say is due to the cheap ammunition "cci blazer 115grain" and prolly not being oiled enough, but that is another question I will ask towards the bottom of this post. Yes I always load 1 then shoot, then load 2 then shoot, then load 3 then shoot, then load full mag. I do that to make sure the BHO is functioning properly. I checked the extractor on the bolt as some have suggested, and it looks fine and it tight.
My next question is how wet "oiled" does a 9mm like to be? At this time it is a little dryer than I normally run my 5.56 ar's. Thanks again for all the help.. ETA to add pic's 
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| What action (buffer) spring are you using? Standard carbine spring? Are you using any spacers inside the back of the receiver extension (buffer tube)? Also, how is the ejector on your DDLES lower? Does your ejector have any play/looseness? It should have some. Jon from DDLES said that the ejector is a free-floating design to eliminate any adjustments to the ejector. |
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Spikes T2 with a carbine spring. The rra buffer malfunctioned more often. But I believe I just figured out the problem, the cheap blaZer ammo. Just dumped 96 flawless rounds of federal 115 grain brass cased ammo through it, and it even feels better shooting it. I'm gonna try the RRA buffer in it thursday.
Eta yes the ejector has some looseness, and I have 4 quarters under buffer spring. |
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Quoted:
A notched hammer will have problems with some bolts. I can't recommend one out of the box for any arbitrary bolt because of the difference between different bolt ramp angles and how much notch with what dimensions the hammer has. If your DD FCG works consistently, notched or not, keep it. But I think you've lucked out with this combination.
The only thing is it is a notched hammer, which some people say will not work. |
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Quoted:
Jon from DDLES said that the ejector is a free-floating design to eliminate any adjustments to the ejector. The ejector need to be "high and tight" with the bolt due to manufacturing differences and tolerances. Is the DDLES ejector spring loaded or is it just loose? Ideally, I would prefer a nice and tight ejector that can be set to the proper position and will remain there, rather than one that "floats"... If it floats too far, you may get erratic ejection issues... Hahn upgraded their bottom load and dedicated top load blocks a year or so ago so all their ejectors are secured internally and do not "float". Quoted:
But I believe I just figured out the problem, the cheap blaZer ammo. Posted in your other thread also - ditch the aluminum blazer in blowback guns. It works for some and not for others - best to stay with brass cased ammo to avoid function issues related to ammo. |
| Also wanted to add that Two of my Metalform mags had curved lips, and they were contributing to the feeding problem. Got them replaced with the straight lipped ones, and now this gun is 100%.. Will update back after I get about 500 rounds with no malfunctions.. |
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