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Old 12-29-2019, 07:36 PM
JohnHL JohnHL is online now
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Quote:
Originally Posted by BLUEDOT37 View Post
I wondered how easy it would be to convert the 4040PD to shoot the 357Sig, being it's on the 9mm frame & already a .40.

I tried my 3914DAO & 3913TSW barrels in the 4040PD.

The dimensions at the chamber are essentially the same & the hoods are close & don't seem like they'd be a problem, but the difference in diameter of the muzzle was sloppy (about .010" difference). How much difference for yours?

The tip to the 40's barrel is belled while the 9mm's is more hour-glass shaped.
S&W used two different sized, fixed (pressed in) barrel bushings.
One for the 9mm single and double stack pistols(smaller i.d.) and one for the 40 s&w double stack pistols (larger i.d.).

A third, larger barrel bushing was used on the single stack 40 s&w pistols built on the 45 frame (i.e. the 4013/4 non-TSW models), but we aren't talking about those now.

That is why a 9mm barrel is loose in a 40 s&w slide with a 40 s&w barrel bushing and a 40s&w barrel won't fit in a 9mm slide with a 9mm barrel bushing.

The only exception are the 4" barreled 5903/5906/5943/5946TSW and the 4" barreled 4003/4006/4043/4046TSW models.

Both use the larger i.d. 40 s&w fixed barrel bushing (probably for some commonality in manufacturing).

I believe the hole S&W bores in the muzzle of the slides is the same size and swapping the bushings is easy enough, except S&W won't sell the bushings separately to the public.

If you want to swap bushings in your 4040 with a smaller 9mm bushing from a "donor" slide, then you could rechamber a 3913 barrel to work in your 4040.

Quote:
Why did you have to chamfer the chamber mouth?
Cutting the 9mm chamber to the 40 s&w sized 357 Sig leaves a sharp edge at the chamber mouth.
To avoid stress risers and possibly help with feeding (although bottle necked cartridges don't seem to need much feeding help) I chamfered the chamber mouths.


Quote:
The camming lugs are different between the -TSW & non-TSWs?
Yes.

Again, only on the 9mm and 40s&w TSW models and NOT on the 45 TSW (I guess they felt that the lower pressure 45 didn't need it?).

S&W refers to it as "delayed unlocking".
They steepened the angle of the unlocking lugs on the frame and barrel so that the slide and barrel stay locked together for a slightly longer period of time, letting more gas escape the muzzle before the cartridge ejects.

It was designed to lower "felt recoil".

Sorry for the delay in responding.

Holidays and family stuff.

John

Last edited by JohnHL; 12-29-2019 at 09:48 PM.
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