U.S. Patent No. 1,391,496
This patent drawing does not show the “tail” which appeared on many early prototype breech blocks.

U.S. Patent No. 1,401,552
Shows the cam extractor with spring
& plunger that appears on early prototypes.

Two views of a prototype breech block
with tailpiece, clearly showing
the cammed extractor and tail.

Interim Breech Block, shown upside
down, with cartridge guide lug clearly visible (top right).

Production Breech Block, with no
cartridge guide lug, and showing a
shortened, integral tail, just like the
interim breech block.

Copyright 2007
by Ed Buffaloe.