AR Sponsor
Posted: 10/14/2013 9:24:26 PM EDT
|
hello,
I finally got one of my ddles 9mm lowers built and have an upper that I assembled and I am having problems with it. With the upper off the lower I can do a function test and the lower passes normally ie (I pull the trigger and the hammer falls. While holding the trigger back I recock the hammer and the disconnector catches the hammer and when I release the trigger it catches on the sear.) Works perfectly like any ar should. The problem I am running into is when I function check with the upper on the rifle. If I rack the charging handle with the trigger released the carrier cocks the hammer which is normal. I pull the trigger and the hammer falls. While holding the trigger back, if I rack the charging handle the carrier does not recock the hammer and catch on the disconnector like it should which in turn when the trigger is released it should catch on the sear but it does not. The lpk I am using I had in another rifle that ran fine. So I took the upper and put it on another lower I had and the same thing happens. I tried this with three different 9mm bolt carriers and all had the same effect. can anyone help me figure this out? It seems like possibly the carrier is not pushing the hammer down far enough??? but I don't know how that is possible... double and triple checked the lpk is installed correctly. I think this is a problem with the upper as the upper produces the same result on other lowers. Thanks, Thomas |
| What style of hammer and buffer are you using? Trying to use the "9mm" hammer with a ramped style bolt usually results in the hammer not coming back far enough to reset properly. Some ramping styles don't work correctly with any hammer if you're using an overtravel-limiting buffer. |
| it is a standard lpk I believe it was a dpms or a stag kit. all the bolts are cmmg ramped 9mm bolts. the buffer I was trying to use is a standard carbine buffer just to function check. my 9q is gonna be here tomorrow. I evenw ent so far as to take the buffer and spring out of the lower and charge the weapon with the trigger held back and use gravity to get the bolt back home and still the same thing. could it be an out of spec upper? I find it hard to believe that 3 different bolts are messed up... |
|
http://i154.photobucket.com/albums/s243/tommyid1/image-5.jpg
That's the hammer I'm using. Are these not compatible with the cmmg ramped bolts? |
|
Quoted:
Okay so I was under the impression that any std ar hammer will work with a ramped bolt... I read something about a rounded hammer? Do I need a rounded one? Could I just fill the v with weld or just buy a new hammer? You need the hammer without the notch, you can weld it if you want. the one in the middle |
|
Quoted:
Do I need a rounded one? Kinda sounds like it. My ramped bolts won't work at all with anything else, and don't even work reliably with them. Ramped bolts are great but have to be done correctly, which mine were not, along with any others that have a 9mm bolt ramped at the same angle and depth as a standard bolt carrier. |
AR Sponsor