Reaming Model 442 Cylinder for .357 Magnum

[IllinoisFineGuns]

I have a very nice Stainless Steel Model 442 in .38 Special +P.
I noticed that the cylinder is long enough to accept a .357 Magnum cartridge, except the cylinder has not been reamed all
the way through to accept the cartridge. If I were to ream the
cylinder all the way through, the .357 Magnum cartridge would fit
into the cylinder perfectly. My question is: Would the frame tolerate the higher pressure of the .357 Magnum cartridge?

 

[AJ]

Talk to a qualified gunsmith. If he is willing to warrantee his work then maybe. I would just buy a .357 snub light weight. Just sold a S&W 342 Ti in .38 Special. With +P ammo it hurt my hands with arthritis to shoot. They made a model to replace this but not sure what it was. Not real pleasant to shoot.

 

[murphydog]

Welcome!

The model 442 has an alloy frame and a carbon steel cylinder. The factory makes alloy frame .357s, presumably built to handle the 35000 psi maximum pressure of this round as opposed to the 21000 psi of .38 Special + P. With this 67% increase in pressure and the availability of .357 J frames I doubt this is a wise idea.

 

[Glashaus]

Just get a 640-1 before you grenade your alloy frame 442

 

[tlawler]

Don’t do it!

 

[Ackley1952]

Listen to AJ

 

[pasound]

Don't do it. Get a 60-15. It's steel, still beats the **** out of me with magnum loads, (even with Hogues) but at least will take them...

 

[s&wchad]

I have a very nice Stainless Steel Model 442 in .38 Special +P.
I noticed that the cylinder is long enough to accept a .357 Magnum cartridge, except the cylinder has not been reamed all
the way through to accept the cartridge. If I were to ream the
cylinder all the way through, the .357 Magnum cartridge would fit
into the cylinder perfectly. My question is: Would the frame tolerate the higher pressure of the .357 Magnum cartridge?

NO...
Modern light weight J frames made to handle the .357 cartridge have a much stronger alloy frame that includes small amounts of scandium in the mix. It makes a world of difference...

I’ll aso add that the 442’s have a carbon steel barrel and cylinder and an aluminum alloy frame. 642’s have a stainless steel cylinder and barrel and the same frame as the 442, but with a different finish. Neither are intended to handle the .357 Magnum cartridge.

The 442’s and 642’s are excellent carry guns. If you want to shoot .357’s out of an alloy J frame Centennial, buy a 340Pd.

 

[Screwball]

Personally, if there is a gun available in that chambering from S&W… I’d just buy a 340PD.

Now before everyone starts down the “you’ll blow yourself up” road, I did convert my 642-1 to 9mm. I carry it religiously, and no issues have popped up in the almost six years I’ve had it converted (plenty of other members/shooters on other forums have had similar results). I train a lot with UMC bulk 115 grain, which has a POI identical to my carry rounds (Hornady XTP 147 grain).

 

[steelslaver]

While I might not be as cautious as some people, I don't think this is a good idea. While cylinder is what lets go when a gun blows, we see one once in the while where the barrel blew off, but that is odd and probably due to the thin area under barrel at yoke. I just can't imagine it is good for the top strap and lower area of an alloy frame. I for one do believe the scandium alloy frames are quite a bit stronger that normal aluminum alloy frames, but still the amount of material is just not there

But, to me the main thing is a small alloy J frame is a small concealable self defense tool. It ain't a target gun, it ain't for hunting. IF you ever need it to save your life you best be good with it, and that means 2 things, you need to practice with it and you need to do that with what you carry in it. So, besides probably being hard on your gun it will be really hard on YOU, and if you need to get off multiple shots off in a hurry to save your buns that extra recoil WILL work against you. Remember, fire power is fine, accuracy is final.

I recently picked up a airweight 637 rated for +P and it is enough of a handful that I wouldn't want to fire 357 magnums in it.

 

[hyena]

Welcome to the forum. Looks like you're from Illinois. Let me know if you decide to follow through with that. I want to make sure I'm not anywhere close by when you shoot it.

 

[Seven High]

That modification would void the factory’s warranty.

 

[steelslaver]

Midway has titanium J frame 357 cylinders for $137 if your really looking to give your self a sore hand. I do not believe the gun will blow up, the factory made 357 cylinder wouldn't, But, once again I think it isn't a good idea even if the gun don't let go. Besides the alloy +P J frame I have a 640-1 J 357 all steel and I only feed it 38s. I wear XX gloves and have worked steel all my life, I can take the recoil for a couple cylinders, but I can put 5 round in a paper plate at 7 yards faster with a J 38 than a 357.

I mostly carry a 325 snub which is a handful, but has bigger grips and about twice the weight of a alloy J frame

 

[Jason Demond]

One should bow to conventional wisdom on things like this.

Sure a person could do this, and the frame may even take it for a bit. The real question you should be asking yourself, is how much you value your functional hand. You probably wouldn't lose it, but do you really want to take the chance?

 

[stansdds]

I would not try to convert a Model 442 to 357 Magnum.



I'm sure the cylinder strength would not be the problem, but I'm not sure the frame of the 442 will handle the recoil impact of the cylinder banging back and forth under the significantly greater recoil of 357 Magnum.



Should you decide to sell a rechambered 442, you might find that no one will buy it.



Personally, having a 640-1, I cannot imaging firing 357 Magnum loads in a lightweight revolver. I now stoke mine with 38 Special +P. I'd rather have a firearm and ammo combination that I can easily control and deliver rapid and accurate follow up shots than one that is going to be more than a handful to control and slow to get back on target.

 

[gwpercle]

Light weight , J-frame 357 magnums are a brother trucker to shoot ... the recoil is vicious , follow up shots are slow and poor , muzzel blast is disconcerting ... you seldom are given time to don ear protection in an emergency .
Do what you want ... I've been there , done it , didn't like the results and have gone back to 38 Special ammo in a 637 AirWeight that I can shoot accurately with fast follow up shots .
Remember .... Only hits count ... a magnum miss could get you killed ...
Gary

 

[M29since14]

I wouldn’t ream it. The idea of an Airweight .357 J-frame is overrated, IMO. I have said it before: S&W missed the boat with the 340PD. If it could be done properly, and I presume it could be, a 940PD would have been a much better idea. I would buy a spare cylinder for my 340 and have it reamed for 9mm, but that is not really an ideal way to proceed.

 

[mikerjf]

Per Screwballs 9mm post, I never really noticed before that 9mm and 357 have the same max pressure rating (35,000 psi).

Consider that the 9mm 1) requires cylinder material removed because of the slightly larger diameter at the base; and 2) being shorter, applies the pressure to a smaller length of the cylinder.

Seems like 9mm should be harder on the cylinder than 357.

 

[smithra_66]

Don't mutilate a good gun.

Buy a 357 snub if that's what you want.

 

[lefty_jake]

I would not convert an alloy .38 special to .357 for all of the reasons discussed in this thread.

But I do want to mention that for firing .357 in any J-frame, grips make all the difference. What really makes a J-frame painful under recoil is the small and concealable grips. A larger grip makes a big difference in spreading the recoil impact, and this greatly improves the feel in the hand.

I have fired some .357 rounds from a 340PD with Pachmayr Compact grips, and it was tolerable. I am not saying it was pleasant, but it was potentially usable. With smaller grips on an alloy frame, .38 +P would definitely be my limit. And I am sure the larger grips would help even more on a heavier steel frame.

But the tradeoff is size. The Pachmayr grips are large enough that they make the whole gun larger than people want from a J-frame. I should also note that what really matters is the thickness at the top of the grip. The force needs to be spread out in exactly the area where your hand hurts, which is generally from the base of the thumb over to the forefinger. Many grips are fatter near the bottom, which I do not find is a useful shape for cushioning recoil.