Common mistakes made by a home build

[PhuLish]

I was recently reading a thread about how carbine instructors say most problems that occur during class come from a home build. What are the most common malfunctions that occur besides having it blow up in your face? My first problem was I didn't properly align the gas block, the gun would cycle but wouldn't stay open when the last round was fired.

[Leonidas24]

Hammer spring backwards, mis-aligned gas block, and improperly torqued barrel or bolt carrier key are the main mistakes I can think of.

[Nightgunner]

Trying to save a buck and buying low quality parts. Ask me how that one worked out :mad:

[PhuLish]

Trying to save a buck and buying low quality parts. Ask me how that one worked out :mad:

What was the result of that?

[BCmJUnKie]

Hammer spring backwards, mis-aligned gas block, and improperly torqued barrel or bolt carrier key are the main mistakes I can think of.

Not to mention springs/detents reversed, unstaked/improper staking jobs, castle nuts reversed, sights reversed, gas tubes misaligned, torque specs not met.

"Tight enough" or "Thats good" is not on the side of any torque wrench I own

[Nightgunner]

What was the result of that?

FTE, FTF, and buying the part twice. Once the cheapo, second time for good.