ecrawmer
Member
I'm just curious if anyone's had tried this out before. Does it essentially turn the gun into DAO or is there something else I'm missing?
Anyone try putting a DAO hammer in their DA/SA?
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Dragonwycke
Member
I don't know but this guy does. He's the Man at LSG Mfg. in Commanche, TX. and is a S&W Warranty facility. Does excellent work! [email protected] (Frank Smith)
Pisgah
Member
The only difference between DA/SA and DAO only is that the DAO hammer has no single-action notch. You can take a regular hammer, file off the SA notch, and voila -- DAO.
Fastbolt
Member
There are some differences in the parts used in the DAO & Traditional Double Action (TDA, commonly also called DA/SA) metal-framed S&W pistols.
In general, each type uses different hammers, sears and triggers.
In addition to the frame & slide differences between the original (old) and new style DAO models, machined hammers & sears were used in the old DAO models.
Newer DAO guns use MIM parts.
The proper combination of hammer & sear MUST be used, meaning machined hammers used with machined sears and MIM hammers used with MIM sears. Improperly trying to mix hammers & sears will result in improper contact at critical spots between the parts.
The DAO trigger assembly is different than the TDA trigger in an area behind & above the trigger (not visible from outside of the frame when the gun is assembled).
Also, in DAO guns the sear release lever is a 'spacer', lacking the bottom leg (since decocking isn't needed) and having 2 small holes in the upper part of the lever).
The TDA hammers have sets of paired notches called the Single Action notch, Pickup notch and the Throw notch (corresponding sets of notches in the drawbar engage the Pickup & Throw notches to draw back the hammer and fire it in DA when the trigger functions the drawbar in DA mode).
The DAO hammer has a Location notch and a Throw notch. When the gun is 'charged' (slide retracted and released, such as when loading the chamber) the hammer is 'located' to the rear by the sear nose so the throw notch can be rotated forward and engage the drawbar. The sear nose does this by catching & fitting inside the hammer's location notch.
The DAO & TDA hammers are totally different in configuration. The DAO hammer's location notch is NOT the same as the TDA hammer's pickup notch (or any other notch on a TDA hammer). Not even close. A DAO hammer IS NOT a TDA hammer with the SA notch ground off. FWIW, one of the causes of unwanted/unintended double-taps & bursts in a S&W TDA gun (which is obviously a safety concern & problem that should be immediately corrected) is the hammer's SA notch being damaged or worn so that it's unable to catch and hold the hammer in SA. (Could also be caused by a damaged sear or sear spring, too.)
The 'new' MIM sears can be used in the new-style guns with either TDA or DAO hammers as long as MIM hammers are being used. (There's an interesting story and bit of trivia I heard in an armorer class about how & when this was determined, but that's a story for another day.
)
S&W factory technicians, a licensed gunsmith familiar with S&W pistols or a certified S&W armorer can convert a new style TDA pistol to DAO (and replace the manual safety assembly with a firing pin retainer, if desired) using the appropriate parts.
The new style DAO parts were designed with being able to convert the then-new TSW guns from one design to the other by LE customers, instead of having to buy different guns if a change in design/operation was desired.
Converting a gun with a regular TDA slide (which is shorter at the rear than the old-style DAO slides) means the DAO hammer can't be 'located' (partially cocked, so to speak) as far to the rear, which means the new-style DAO parts give a little longer DAO trigger stroke than was needed in the older style dedicated DAO guns.
This info is naturally somewhat over-simplified, and there are some other things involved when discussing old & new style DAO guns & parts, but it explains some of the differences involved.
In general, each type uses different hammers, sears and triggers.
In addition to the frame & slide differences between the original (old) and new style DAO models, machined hammers & sears were used in the old DAO models.
Newer DAO guns use MIM parts.
The proper combination of hammer & sear MUST be used, meaning machined hammers used with machined sears and MIM hammers used with MIM sears. Improperly trying to mix hammers & sears will result in improper contact at critical spots between the parts.
The DAO trigger assembly is different than the TDA trigger in an area behind & above the trigger (not visible from outside of the frame when the gun is assembled).
Also, in DAO guns the sear release lever is a 'spacer', lacking the bottom leg (since decocking isn't needed) and having 2 small holes in the upper part of the lever).
The TDA hammers have sets of paired notches called the Single Action notch, Pickup notch and the Throw notch (corresponding sets of notches in the drawbar engage the Pickup & Throw notches to draw back the hammer and fire it in DA when the trigger functions the drawbar in DA mode).
The DAO hammer has a Location notch and a Throw notch. When the gun is 'charged' (slide retracted and released, such as when loading the chamber) the hammer is 'located' to the rear by the sear nose so the throw notch can be rotated forward and engage the drawbar. The sear nose does this by catching & fitting inside the hammer's location notch.
The DAO & TDA hammers are totally different in configuration. The DAO hammer's location notch is NOT the same as the TDA hammer's pickup notch (or any other notch on a TDA hammer). Not even close. A DAO hammer IS NOT a TDA hammer with the SA notch ground off. FWIW, one of the causes of unwanted/unintended double-taps & bursts in a S&W TDA gun (which is obviously a safety concern & problem that should be immediately corrected) is the hammer's SA notch being damaged or worn so that it's unable to catch and hold the hammer in SA. (Could also be caused by a damaged sear or sear spring, too.)
The 'new' MIM sears can be used in the new-style guns with either TDA or DAO hammers as long as MIM hammers are being used. (There's an interesting story and bit of trivia I heard in an armorer class about how & when this was determined, but that's a story for another day.
)S&W factory technicians, a licensed gunsmith familiar with S&W pistols or a certified S&W armorer can convert a new style TDA pistol to DAO (and replace the manual safety assembly with a firing pin retainer, if desired) using the appropriate parts.
The new style DAO parts were designed with being able to convert the then-new TSW guns from one design to the other by LE customers, instead of having to buy different guns if a change in design/operation was desired.
Converting a gun with a regular TDA slide (which is shorter at the rear than the old-style DAO slides) means the DAO hammer can't be 'located' (partially cocked, so to speak) as far to the rear, which means the new-style DAO parts give a little longer DAO trigger stroke than was needed in the older style dedicated DAO guns.
This info is naturally somewhat over-simplified, and there are some other things involved when discussing old & new style DAO guns & parts, but it explains some of the differences involved.
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Cruiser RN
Member
I am not a gunsmith but I love the DAO Configuration.I sent my CS9 back to S+W for the conversion and a trigger job.It came back with the old DA/SA switch and slide holes filled.They also sent back the removed parts if it ever is changed back.the 175 dollars was well spent and judging from the returned parts it is a little more work than changing the hammer.....God Bless......Mike
Fastbolt, thanks for all the great info! That was very helpful. I do have another question. I know on the older Second Gen guns they had a built in half cock notch on their hammers. You could feel the notch when pulling though DA. On these hammers since they have that half cock notch would eliminating the SA notch work to keep the guns from going full auto?
I'm learning new stuff everyday!
I'm learning new stuff everyday!
inboost
Member
Great info Fastbolt, thanks for sharing it! So it sounds like for a later gun with MIM parts the required items for a conversion would be
- DAO Trigger
- DAO Hammer
- DAO Sear Release Lever
- Firing Pin Retainer
The odd thing is that the website published S&W parts list shows the trigger as the same part number across all models of CS45 (gun I'm working on now). It only lists a different hammer, firing pin retainer, and sideplate assembly of all things for the CS45D model which appears to be the DAO version of this gun. It also lists the same sear release lever across all models, but I suspect if the firing pin retainer is replaced with the leverless plug the DAO units use then it's no problem to leave the release lever in the gun the way it sits? I would hope the firing pin retainer plug for the DAO would have a slot cut to clear the release lever.
Does one typically need to fit any of these parts or are they production line drop-in tolerance items?
KurtC
Member
The CS45D uses a different setup than the TSW DAO models. The CS45D fires from a full stroke of the trigger (the hammer is never partially cocked). Therefore, it uses the same trigger as standard DA/SA models.
If the factory converts a CS45 to DAO, they use the partially cocked version as used on the TSW models.
If the factory converts a CS45 to DAO, they use the partially cocked version as used on the TSW models.
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inboost
Member
KurtC,
Thanks for filling in the gaps for me. So I suppose if I wanted to build a factory style conversion that leaves the hammer in a pre-charged state I'd need to grab parts from another chassis in the 455x series?
Thanks for filling in the gaps for me. So I suppose if I wanted to build a factory style conversion that leaves the hammer in a pre-charged state I'd need to grab parts from another chassis in the 455x series?
KurtC
Member
The part numbers should be the same for the 4553TSW, 4586TSW and 4583TSW. Do not use the 4553TSW OBS (Obsolete).
inboost
Member
Thanks for the clarification KurtC. The hammer and trigger indeed have different part numbers from the CS45D model.
for the CS45D (all models really)
for the CS45D (all models really)
- 262190000 TRIGGER ASSY, BLUE
- 266610000 HAMMER ASS'Y DA
- 266850000 TRIGGER ASS'Y
- 266880000 HAMMER ASS'Y
Another question for the experts...
So if I wanted to make my 908 a DAO gun could I simply get this hammer & sear kit?
Smith & Wesson Hammer and Sear Kit S&W 1086, 3944, 3946, 4586, 5943, 5943SSV, 5944, 5946, 3953, 3954, 4054, 6944, 6946 - MidwayUSA
Thanks, mostly just curious, but for $41 it's not too much if I just wanted to try it out.
So if I wanted to make my 908 a DAO gun could I simply get this hammer & sear kit?
Smith & Wesson Hammer and Sear Kit S&W 1086, 3944, 3946, 4586, 5943, 5943SSV, 5944, 5946, 3953, 3954, 4054, 6944, 6946 - MidwayUSA
Thanks, mostly just curious, but for $41 it's not too much if I just wanted to try it out.
KurtC
Member
That kit appears to be for the early DAO models, which had the proprietary frames and slides. For a 908, I believe you would need the DAO parts designed for the late models, such as the post '99 model 3953TSW.
