Why do automatic pistals have holes in the hammers?

[TFLeader]

Why do many automatic pistols have holes in the hammers? Broomshandles and Browning Hi Powers come to mind.

Is to to reduce weight? Seems like that could be done other ways. Many of the ones I have seen actually have several machining steps in the hole making process, like the size configuration of the hole is important.

 

[Stef]

A lighter hammer moves faster which reduces lock time.

 

[TFLeader]

A lighter hammer moves faster which reduces lock time.

Agree, but usually military firearm production has a lot to do with cost and number of machining steps. The hole requires an additional (if not more, some holes are counter bored on both sides) steps. Why not just lighten the design like a 1911 hammer. I have to think the round hole has an additional reason.

 

[MACGYVR]

My theory is the hole strengthens the hammer. It prevents the hammer from deforming overtime. If you notice, that hole is directly lined up to strike the firing pin. All the forced is placed on the pin side of the hole and the hole transfers the impact around itself sending that force up and down in the hammer.

If it was solid, the forced would go straight through the hammer horizontally and would eventually create a stress fracture.

 

[MisterHappy]

My late dad (WWII Small Arms Armorer) explained it to me this way: The rounded hammer made it easier to cock (on a SA, e.g Browning Hi-Power) by pushing it down on your leg ( or saddle, if mounted) Remember, when auto pistols were introduced, cavalry was still a force to be reckoned with. Not saying that this is the "real" reason, but a lot of military practice and "tradition" dates to this sort of thing. Now, if we take this theory on face value, then the hole in the rounded hammer will lighten it, and, as stated above, reduce lock time.

Once this is established as the "correct" way to make a hammer, tradition and inertia take over, and absent a REAL NEED for change, it will stay.

Of course, on a pocket pistol the rounded hammer makes it less likely to snag, while still giving the option of cocking / lowering the hammer by hand.

 

[jpattersonnh]

OK. the real reason is... Start at a more modern firearm. The Sig P6 has a cut and drilled hammer. Why? If the pistol was dropped and the handgun is out of spec a simple gauge will tell. Pretty simple!