Thanks to Joel Babcock for allowing me to repost this thread from the 1911Forum :
http://forums.1911forum.com/showthread.php?t=130683
From Joel Babcock:
"Attached are some photos from the late 20's to the late 30's of a few phases of production. I will not publish photos undoctored at this time. I'm sure you'll understand I don't own the rights to do that....I doubt.
The Colt Factory

The Steel Room, hundreds of different types of steel; rods, bars, flats, and strips waiting to begin their journey through the plant.
The Forge Shop, where gigantic drop forges beat such parts as frames, slides and receivers from solid bars of steel. The pile on the left in the photo are receivers, and slides on the right.
The Heat Treat Room, where the ovens give steel the proper strength and toughness.
Drilling Machines, where millions of holes are drilled in receivers and frames every year. Note the rack of receivers lower left in photo.
Broach Machines, for cutting out the inside sections of frames and receivers. Note the rack of receivers lower right in photo.
Profiling Machines, note the stack of receivers between the workers.
Barrel drilling machine, where the barrels are drilled in a delicate operation necessary to produce a perfect barrel.
Barrel rifling machine, an operation that calls for skill, care and years of training....done on a machine of special design.
Barrel Proof testing machine....this photo was obviously taken in a staged photo, at least it seems the proofer would be wearing some kind of hearing protection as the proof loads were 25% overloads.
Rough polish, this worker is working on Woodsman pistols.
Final Polish room, where small and large parts are polished.

Bluing Furnace, a drum revolves slowly until the operation is completed. They are built to hold a maximum number of pieces, yet allow ample room for air circulation with no chance for parts touching each other. There are racks for barrels, racks for hammers, triggers, extractors, grip safety, etc. All screws and pins are blued in bulk in the small furnaces. Matched parts, such as slide and receiver are alternately fastened in place in the bluing rack. The bluing room has twin rows of revolving drums - thirty large furnaces and eight small parts furnaces.
Assembly Room, dozens of highly skilled experts fitting parts until complete.
Grip Checkering room, where hand checkering is putting on the sharp diamond points for automatic pistols and revolvers.
Repair/Shipping Depts. under the Supervision of one individual, and the pistols are boxed, wrapped and shipped.
Stock Room, guns ready for shipment.

Colt frame forging in my collection.

"
Thanks again Joel for the awesome piece of Colt history!!