will not lock back on empty

[jonny rotton]

i just finished building a 16" aa fluted barreled upper. it will not lock back on an empty
magazine. any ideas what it could be?? i checked the gas block alignment, and the
port is not plugged.

[Jagorrell84]

Does your magazine have the Hold Open on Last Round Tab? What magazine are you running?

[ricsmall]

Give a complete description of buffer type, reciever extension, buffer spring, BCG brand and type and I'm sure we'll get it figured out. Adjustable gas block or no?

Richard

[jonny rotton]

elander and asc mags. fixed gas block that is centered over the gas port. just a regular bolt carrier and ar spring and buffer. i do not know those brands. i did pick up a nickel
boron carrier i will use now.

[Drillboss]

Can we assume that the bolt catch does work when you use the charging handle? If so, I have to suspect an issue with the gas flow. I used a YHM clamp-on for my AA 16" build. Their instructions said to leave a 0.03" gap between the shoulder and the block. And if you keep reading, it says except for the model number I had. I missed that part. Mine would lock back on factory loads, but not with some starting charge reloads. After adjusting the gas block, it worked fine.

[Ragedracer1977]

I have a couple ASC mags that do not 'trip' the bolt catch.

[ricsmall]

elander and asc mags. fixed gas block that is centered over the gas port. just a regular bolt carrier and ar spring and buffer. i do not know those brands. i did pick up a nickel
boron carrier i will use now.

If it's an ar15 neutered carrier as opposed to an m16 carrier, that could be a contributing factor. Sounds like it could be over gassed but hard to say really. Where is your brass landing, if muzzle direction represents 12:00, my brass lands about 3:00 when my gun is running smoothest. Check out the chart below for a good start at troubleshooting. If ur brass is right in the sweet zone, other troubles are present.


ETA. Look at different carriers in added link
Richard

http://rs829.pbsrc.com/albums/zz211/Quentin68/ar15carriers.jpg?w=480&h=480&fit=clip

http://i829.photobucket.com/albums/zz211/Quentin68/ARejectionpattern.jpg

[devildogandboy]

does the bolt catch function freely or is it sluggish like no oil?

Bruce