What keeps pins from falling?

[d_goldsmith]

Real

What I imagine should happen.

Are the pin chambers like this \ / slightly? That doesn't make sense though unless the pins are like that also, but that opens up a whole new set of questions about the top pins.

[n2oah]

The holes for the pins in the plug are only drilled deep enough for the lock to operate. What you have posted is an inaccurate sketch of how the lock actually is. I believe that sketch is to illustrate how the shearline works, not why the pins don't fall out.

[Romstar]

The picture you have posted isn't quite accurate.

The bottom pins do rest on the top ward in the keyway. Your sketch is mearly for illustration purposes.

Take a few locks apart, and you will see where the pins rest.

Romstar

[I Pik U]

The pin holes are round and drilled only part way down into the plug. Usually just a bit deeper than the longest factory spec tumbler.
Not necessarily down to the first ward, as it depends on the keyway shape.

[d_goldsmith]

The picture you have posted isn't quite accurate.

The bottom pins do rest on the top ward in the keyway. Your sketch is mearly for illustration purposes.

Take a few locks apart, and you will see where the pins rest.

Romstar

When you say "The bottom pins do rest on the top ward in the keyway" do you mean that is the way locks work, or that is the way my picture shows?

I can tell by looking in to my locks that the pins rest above what I believe is the first ward, but I guess it is possible that there is a higher ward that I can't tell is a ward?

[d_goldsmith]

The pin holes are round and drilled only part way down into the plug. Usually just a bit deeper than the longest factory spec tumbler.
Not necessarily down to the first ward, as it depends on the keyway shape.

Thank you for not implying that I'm slow and just answering my question

So does that mean the bottom of the drill hole is slightly rounded, causing the pin to stop there?

[Kaotik]

I wouldn't think so, being that the holes will be drilled into the cylinder completely. *If you'll notice the taper on the key pins are the same angle as the top ward they rest on.

Try sticking something like a straight pin or the tip of your hook pick and see if you can pull it down to the ward. The only reason I can think this is happening is the spring is over compressed and the top edge of the key pin is slightly sticking to the flat bottom edge of the driver pin by some lubricant or sticky debris.

[I Pik U]

So does that mean the bottom of the drill hole is slightly rounded, causing the pin to stop there?

The bottom of the holes will be tapered like the end of a drill bit. The keyway passes through these drilled holes. It's the bottom of the holes that stop the pins. Often the holes will go down further than the highest wards.