I bought a preassembled 20" free float, bull barrell upper from model1sales.com and just got a chance to shoot it yesterday. I refuses to eject or cycle the bolt at all. I tried 15-20 rounds from 4 different manufacturers and none of them ejected. The bolt runs smoothly through the upper when hand cycled. I pulled the bolt and the port where the gas enters the bolt was perfectly clean, no fouling at all. This makes it seem like no gas is coming through the gas tube, but I don't know how to check that or fix it.... :confused:

Sounds like a misaligned gas block, or a forgotten gas port.

Call M1S, they should make it right.

does it have a gas tube?
is it upside down?

When you hand cycle a round through it, does it extract and eject the round from the chamber?

If so, it sounds like a gas tube/gas port problem as the others have said.

If not, take a good look at your bcg.

make sure the gaps on the gas rings are off set.

Call the mfg

If you don't want to wait punch the pins on the gas block and take it off to inspect. Google ar gas block removal. Or just call model 1.

Just blow down the gas tube, if you don't get air coming out of the barrel, then the port or gas tube is clogged.

Wether it is or not doesn't really matter, call the folks you ordered it from and tell them its fawked up, they should send you a call tag for it.

buy from pete next time.:flipoff2: