Part BP1169A Small Primer Arm Assembly for product BREECH LOCK CLASSIC CAST
A square hole is present on the side of the Primer Arm. If your Primer Arm does not have this feature, you would need the part.

Part BP1169A Small Primer Arm Assembly for product BREECH LOCK CLASSIC CAST
A square hole is present on the side of the Primer Arm. If your Primer Arm does not have this feature, you would need the part.
