Odd bolt carrier machining?

[Jerret]

I recently received a bolt carrier where the top portion of the hammer/firing pin area was machined a little differently. Does anyone know of a reason to machine it like this, or have ever seen this before? The best I can guess is some cost savings because of less tool changes and/or it's a mistake.

Thanks.

[lysander]

Simplifies machining. No broaching required.

[Jerret]

Simplifies machining. No broaching required.

Thanks!