So as I was out walking this morning, letting my mind roam about unguided, I realized that I couldn't come up with an example of a DA or DAO longarm.  Oh, I'm sure that someone somewhere somewhen made one, but I cannot think of a contemporary example.  The majority longarms I can think of depend on cycling the action to cock the firing mechanism.  A minority have exposed hammers or firing pins that can be cocked without cycling the action, but they still must be cocked by hand.

Which got me to wondering why DA handguns exist.  I mean, the evolutionary course of the revolver is clear enough.  But once the concept of using recoil to cock the action became established, why didn't DA die away?  There are even semi-auto, single-action revolvers out there, which serve to prove the concept if nothing else.

I expect people will bring up the whole "you want to MEAN to shoot a bad guy" premise.  But, if heavy trigger pulls really DID prevent accidental shootings, then why wouldn't the armed forces or police forces of the world be using heavy trigger pulls on their longarms? 

What do you think?  Is DA a concept that should be developed in longarms, or is it an evolutionary step that should be bred out of handguns?

I didn't look this up on Google like I should. Because I am just going to take a stab at this. Most of the handguns I know (not all but most) replaced a mechanical safety with the DA. In other words, the ability to keep the hammer/firing pin from being cocked until you are ready to fire is about as safe as you can get without a mechanical safety. This removes some mechanism and weight. I suspect you will find DA semi-autos more on the small size frames than on the mid or full size frames.

Rifles are not meant to be holstered and are meant to be shot at longer distances than handguns. Meaning that having a DA trigger will adversely affect ones ability to hit things at 500 yards. Most handgun battles take place within 12 feet or so.

Mossberg 590DA shotgun in 2000-2001. I'm not sure if anyone actually bought one locally.

What do you think?  Is DA a concept that should be developed in longarms, or is it an evolutionary step that should be bred out of handguns?

If there was a market for DA long guns we'd have one by now.  As for DA/DAO handguns, as long as there are police departments and lawyers there will be DA/DAO pistols.

Just noodling this around in my head, my first thought on this is that since rifles have much higher pressures, they have harder primers and therefore need a more energetic firing pin or striker blow. Most bolt rifles are striker-fired, which means a long trip from cocked to fired, which means trigger finger muscles like your bicep.

taurus/rossi revolver type?

http://www.rossiusa.com/product-list.cfm?category=15

Pistol caliber DA rifles

...............What do you think?  Is DA a concept that should be developed in longarms, or is it an evolutionary step that should be bred out of handguns?

DA for longarms...........I dunno.

DA for pistols I think is something that is a reasonable characteristic to keep, especially in revolvers.