I was curious IF I could find all the internal parts would it even be possible? I was thinking about maybe making a 3953NL.

There are other things but the biggie is this part:
Smith & Wesson Firing Pin Retainer S&W 3953TSW - MPN: 266910000

To replace the decock assembly. I believe the sear lever is a must-change alsk but some smart feller will show up with the exact details.
The trigger is WAY better with the 3953 pre-cock slide movement and hammer, which essentially brings the hammer to half-cock each cycle of the slide, but you lose re-strike capability. (Although I think you can accomplish that with a 3913 as well but will need the right hammer)

Would the converted 3913 have the half cock feature with the 3953 guts? I remember reading something about the need of longer slide and frame?

No need for that but you would need the right hammer, unless you wanted to mod your existing hammer.

6906 Conversion to DAO

The answer is: YES (with a qualification)

First, an explanation.

S&W has offered 3 styles of "DAO".

The 1st style was featured in the DAO models with the extended slide and frame.
In this style, the slide "pre-cocks" the hammer about half way with each shot so it is actually more of a half cocked single action.
Because the hammer is half cocked, it protrudes from the rear of the pistol quite noticeably.
That is why S&W extended the slide and frame on these models, to shroud the hammer.
These are generally conceded to have the best "DAO" trigger pull because you are moving the hammer the shortest distance when firing.

You CAN put those internals in a TDA (DA/SA) frame and slide but the hammer will protrude freakishly out of the rear of the pistol when half cocked.

The second style is TSW DAO.
This is essentially the same mechanism as the first style with the exception that the hammer is much less "pre-cocked" than on the original style.
S&W did this so that they could put this action in the standard length slides and frames.
This is the style and conversion parts used in my older thread: 6906 Conversion to DAO
Doing this style of conversion would effectively change a 3913 into a 3953TSW.
Of the 2 partially cocked, DAO styles, these have a longer and less desirable trigger pull than the 1st style.

Last, but not least, is the 3914DAO style. (Also called NYPD, 2nd strike capable, or true double action.)
These are essentially DA/SA pistols that have had the single action notch deleted from the hammer and the manual safety body replaced with a "firing pin retainer" (unmovable dummy safety body).

This 3rd style is the easiest conversion to make but also has the "worst" trigger pull as it is simply the double action pull of the DA/SA pistols.

Does this help answer your question?

John

Learned a few things I didn't know, once again. Besides the pictures, it's one of the main reasons why I'm drawn to this forum so much. You just never know when an education is lurking amongst all the sweet photos.

How do you (or is it possible) to tell which action is in which model? I've passed on a deal or two because of the DOA feature, which I (wrongly) assumed them all to be the last of your descriptions JohnHL.

A "pre-cocked" version sounds pretty interesting to me now. Thanks for the education.

First, look at the hammer.

If the rear of the hammer (where the spur would be) has a weird, half circle shape that protrudes from the rear of the slide, it is a pre-cocked model.
These will have the extended frame and slide.
If it is NOT a TSW model than it is the 1st style.

If it IS a TSW model, it is the second style. (No extended slide and frame.)

The third style has a spurless hammer that looks the same as any other spurless hammer. (Also no extended slide and frame.)
Luckily, there are only a few models with this 3rd style, true DAO mechanism.
If it is a 3914DAO, CS9D, CS40D, CS45D, or 457D (I think) it is a 3rd style, true DAO.
These are the only models of this style I've ever heard of.

John

Those two posts are SO good, they should be a sticky or otherwise linked to or labeled as a forum resource. Fantastic info!

Edited for brevity, not lack of excellence.

I did a conversion of this type using advice from JohnHL. Essentially what he describes here, but he also gave me some tips on doing the actual work.

It works well, but I still ended up converting the 457 back to TDA mode.

It's a technically easy conversion, just a bit fiddly getting all of the parts back in place.

Once the conversion was done, the gun shot fine. The reason I converted it back is because after a while it becomes a bear to shoot. I put the first 50 rounds through with no problem. At about round 75, my forearm started to hurt like heck. I barely made it to 100.

Of course in a self defense situation, I'm unlikely to fire 10, let alone 100 rounds. Still, to remain proficient more than one or two magazines are required.

Of course, I have the parts to convert a 3913 to DAO, except for the 3913 itself. If I find one for short money, I'll likely buy it and do the conversion all over again.

For more sustained shooting, I'll stick with my pre rail 3953TSW.

__________________
Can open, worms everywhere.

The idea of converting my 908 to DAO keeps tugging at my heart strings.

Hmmm. So, I can convert my early (STG) 6906 to DAO and reduce the trigger reach.
I don't know just how much the hammer would protrude, with the first style (like my 5946 with the extended frame/slide).
Tempted to stick the DAO hammer in my 6906 as a mock-up, just to see how it will look.

Also, I'd love to build a 3946.

__________________
What would Jim Cirillo do?

Good heart health is important!

Convert your 908 and protect your heart before the strings get all stretched out.

John

If you're going for a mock-up or test fit, also install the 5946 sear with the hammer.

When you see how much the 1st style hammer protrudes from the rear of the slide in the ready to fire position, I'll wager you probably won't like it.

Using TSW DAO parts, it makes for a slick set-up, but it will NOT be the shorter trigger pull of your earlier style 5946.

John

P.S. Still got the XS1100?