14.5" w/pinned FH vs 16" barrel on an AR15?


ADCO did one for me a couple years back, about $50 once the shipping was paid. Any device will work you just have to be sure it gets to the 16 inch mark, most go 16.1" to be safe. If you use a Flaming Pig like Robo did above make sure to take into account the front portion with the cone that is removable does not count in the measurement, only what is permanent.
ADCO has several services and will answer any questions if you call.


Can they chop chrome lined barrels?


Yes. Randall has a whole article about it.