Breech pin

Breech´ pin`

1.A strong iron or steel plug screwed into the breech of a musket or other firearm, to close the bottom of the bore.
Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
Removing the new multiple breech pin differs from the original.
This is all you need do to remove the breech pin. Warning: In sliding off the dustcover to the rear, after about 3/8-inch of dustcover rail is exposed, a recess with a small coil spring and ball bearing are revealed.
Use the firing pin to push out the breech pin (#014) by pulling the barrel slightly forward and holding it there as you push.
You install the firing pin and its locking piece after reinstalling the breech pin.
Slide the breech pin and toggle out towards the rear of the barrel extension (6).