Picked up and minor league lower and a decent lower parts group. Installed a carbine buffer spring and a decent baseline buffer. First time try out, with Hornady .300 whisper, first couple of rounds fired and ejected. Then, click, no fire. No auto eject. Manually eject a live round. Load a fresh round. Bang. Again no auto ejection, had to manually eject a live round again and insert another round to fire.
Trying to trouble shoot problem. The buffer spring in the Magpul battle stock is 11 inches long uncompressed. I do have another spring in the drawer in 10.5 inches. Any clues on if I used the wrong buffer spring? Froglubed, 22 degrees F. Wondering if lower lower quality lower parts group trigger/hammer could contribute.
Really could use some help. The Noveske ran so well on my patrol rifle and I just wanted to build a dedicated lower to avoid swapping the .223 for .300. Thanks.
I can almost guarantee the hammer spring is not full power. Try swapping it out with a different, full power spring. I had the same problem using a JP lightweight hammer spring. I swapped it out for the heavier one and threw away the lighter spring.
Thanks in advance guys. As stated in first post, Hornady .300 Whisper Basically a no name LPK. What I’m trying to describe is that the issue is intermittent. I have to manually load a round into the chamber to get the rifle to fire. Sometimes it does fire. Sometines it doesn’t. LPK was installed by new armorer. Gas block solid. Dry fire on bench is perfect ie charge handle, pull trigger, hammer falls. Primer strikes on fired cases are solid. Four of the ejected rounds that did not fire have a incredibly light (hard to see) firing pin strike. The lower is a “AR Fifteen” lower from Kent, WA. Could we discuss disconnector spring proper installation?
If the disconnector spring is lost the AR becomes a single shot. Pulling that charging handle gets old after awhile
Shine a light down into the trigger assembly and you should be able to see if the disconnector spring is still seated properly. The spring should seat all the way at the bottom of the trigger assembly and “lock” in to the machined groove.
The fact that you are getting light primer strikes makes me wonder if there isn’t something else wrong with your trigger installation.
The disconnector is held in the receiver by a pin through it. It will move with or without the disconnector spring assuming the hammer is in the vertical position.
Take out the trigger assembly and check it. It’s just two pins.
Mark and Lew, I went ahead and removed both trigger and hammer assembly and I found that the disconnector spring was indedd upside down so I put the fat end of the spring down and looked everything else over. Mark, the spring is not yellow, could you share what that would mean, if so? thanks again guys :dance3: ill give it another test in the same weather, just colder.
If the disco spring was upside down, you found your problem. JP sells yellow and red reduced power springs which are know for light primer strikes. I would test again when you can and bet you will be fine.
TacMark and Lew… winnah, winnah, chicken dinna… combo of upside down disconector spring and after I dug up some illustrations of how a hammer spring should appear installed, and it wasn’t correct, I went in, made the corrections and took the .300 out in 13F and unloaded a mag without a hiccup. Thanks guys.
Keep your weapons as far away as possible from “THAT” armorer. He botched two simple procedures that are correctly shown in numerous videos and manuals. The guy actually gets paid to be that incompetent? So sad.
This thread should be a learning tool. The next time someone says I don’t need to learn how to work on my AR, or any competent “gunsmith” can do basic work on an AR I want to direct them here.
I’ve learned through experience of 25 plus years around guns (new to the AR platform)the difference between armorers and gunsmiths, no offense, to either specialty vs. career. In this case, I was giving a new armorer (volunteer) a chance to build up a lower for me for his experience and self confidence. I’d never take a weapon from armorer or gunsmith and deem it worthy without a test drive. In my case, I actually learned a couple of lessons from this build from a human riding a learning curve… and with the help of my M4 friends, the case of trouble shooting a new build. I will have a low key talk with said armorer, pointing out the errors, especially Eric’s illustrated epic and most frequented cause of light primer strikes on the new AR build. Be safe.
Basically a no name LPK. What I’m trying to describe is that the issue is intermittent. I have to manually load a round into the chamber to get the rifle to fire. Sometimes it does fire. Sometines it doesn’t. LPK was installed by new armorer. Gas block solid. Dry fire on bench is perfect ie charge handle, pull trigger, hammer falls. Primer strikes on fired cases are solid. Four of the ejected rounds that did not fire have a incredibly light (hard to see) firing pin strike. The lower is a “AR Fifteen” lower from Kent, WA. Could we discuss disconnector spring proper installation?
