Converting J frame to shoot 9mm

Screwball · #**151** 05-09-2022, 09:07 PM

Quote:

Originally Posted by JDinAZ

I’d like to read about the 942 you mentioned. Web search doesn’t pop up a good page with info on it. It’s probably the same setup as my 296 was. Airweight as in scandium frame

Title on top of the pages, written by Supica and Nahas.

JDinAZ · #**152** 05-09-2022, 09:16 PM

Quote:

Originally Posted by Screwball

Title on top of the pages, written by Supica and Nahas.

That’s pretty cool. Was hoping it was a titanium cylinder hens teeth gun to look around for one

I see it says allow but doesn’t specify aluminum or scandium. That would be an interesting determination to figure out for sure

Screwball · #**153** 05-09-2022, 09:33 PM

Quote:

Originally Posted by JDinAZ

That’s pretty cool. Was hoping it was a titanium cylinder hens teeth gun to look around for one

I see it says allow but doesn’t specify aluminum or scandium. That would be an interesting determination to figure out for sure

Aluminum…

942 came out in 1999.

JDinAZ · #**154** 05-09-2022, 09:59 PM

Quote:

Originally Posted by Screwball

Aluminum…

942 came out in 1999.

I see that a prototype was done then. Did they also do a production run for the public.

Some of my interest and subsequent reluctance with the 357/9mm in a 38 frame thing comes from many folks contacting me to ask if I will run conversions on my CNC for them. I have the programming already written as I built the fixture and CNC machined a test on an aluminum round to fit moon clips about four years ago.

I’ve never agreed to do it for anyone due to the rating on the aluminum frame guns not being stamped 357/9mm. Only marked 38 If this all proves out to be true that the aluminum frame is actually rated for 357/9mm I may have to start doing the conversion for folks.

If it proves safe to do I’d be thankful to y’all for proving it is safe, as I could probably pull it off at a very reasonable cost for folks cnc machined, reamed, chamfered, polished.

JimCunn · #**155** 05-09-2022, 10:04 PM

"Post the calculations that support your claim that the aluminum j frame is engineered to handle 357 and 9mm"

You and I both know that I have never made that claim, and that you have never posted anything to support your assertion that the engineering design is inadequate 😉

Screwball · #**156** 05-09-2022, 10:04 PM

No, it was the one gun that went to Clapp… who didn’t give it any praise. It is currently in a private collection.

Got to remember, the 940 wasn’t a success in any angle. People remember cases sticking, unless you shot +P. Add in J-frames being difficult to shoot, and nobody liking the lighter .357s… it probably was a good thing for S&W to pass than it be a ****** product. Another thing to add, ammunition isn’t where it is now. Hornady crimps are perfect, whereas other companies could lead to crimp jump.

Not arguing/starting stuff, but what round count would you consider “safe?”

JDinAZ · #**157** 05-09-2022, 10:33 PM

Quote:

Originally Posted by JimCunn

"Post the calculations that support your claim that the aluminum j frame is engineered to handle 357 and 9mm"

You and I both know that I have never made that claim, and that you have never posted anything to support your assertion that the engineering design is inadequate 😉

As I posted above on this page. I actually hope I am proven wrong on the true rating of the aluminum frames. I’ve told so many people no over the years when they ask if I convert cylinders for 9mm. I already wrote my CNC program to do it years ago but never have done it for anyone

I’ve always said no cause the aluminum guns aren’t marked for that kind of pressure. Which is all the data that is needed to supoort my assertion.

I’m not here to butt heads with anyone.

But you did claim that the aluminum frame is fine for 357/9mm but no engineering data to support that

Would you endorse putting a 357 cyl with 357 ammo on an aluminum J frame

JDinAZ · #**158** 05-09-2022, 10:42 PM

Quote:

Originally Posted by Screwball

No, it was the one gun that went to Clapp… who didn’t give it any praise. It is currently in a private collection.

Got to remember, the 940 wasn’t a success in any angle. People remember cases sticking, unless you shot +P. Add in J-frames being difficult to shoot, and nobody liking the lighter .357s… it probably was a good thing for S&W to pass than it be a ****** product. Another thing to add, ammunition isn’t where it is now. Hornady crimps are perfect, whereas other companies could lead to crimp jump.

Not arguing/starting stuff, but what round count would you consider “safe?”

I’m not arguing either man. I stick with what the guns are marked for. I may be playing it too safe. Who knows

I’m just reluctant since the factory doesn’t make an aluminum framed 357. From a manufacturing and marketplace standpoint it’s hard to believe that smith wouldn’t make an aluminum framed 357 for just a couple bucks more than the 38 only. If the frame would take it in accordance with their engineering standards

It’s be a big win in additional volume sales to say the least. A pocket rocket that would run either 38 or 357 for about 550. Rather than 1000ish for a 340/360. I think the 642 shows about 538 retail on smiths site. It’s be no more than chambering cylinders a little deeper for the longer 357 case

Heck they could mark em 38/357 so even new gun folks know 38 is fine also if they don’t want to sledgehammer their hand with 357

But there has to be a viable reason they don’t make em like that

Maybe it’s also a flame cutting thing. Don’t the scandium 357s have a blast shield up under the top strap. My 329PD does

JimCunn · #**159** 05-09-2022, 10:59 PM

"Maybe it’s also a flame cutting thing"

And maybe not.
My three aluminum framed, titanium cylindered 637-2 9mm J-frames haven't had any problems with flame cutting.

JimCunn · #**160** 05-09-2022, 11:06 PM

"But you did claim that the aluminum frame is fine for 357/9mm"

Post a quote, in context.
That said, I've noticed that so far, my three 637-2 titanium cylindered 9mm J-frames have incurred zero damage from 9mm. I have .357 titanium cylinders for them, but don't shoot .357 because 9mm recoil is painful enough.

JDinAZ · #**161** 05-09-2022, 11:08 PM

Quote:

Originally Posted by JimCunn

"Maybe it’s also a flame cutting thing"

And maybe not.
My three aluminum framed, titanium cylindered 637-2 9mm J-frames haven't had any problems with flame cutting.

Cool then it rules that out

Can you answer the question I asked above

Being that you have an aluminum j frame. Would you say it’s safe put a 357 cylinder on it and run 357 ammo in it

Do you see where my conundrum in this whole thing is. No one will endorse using a 357 cyl and ammo in an aluminum j that is marked for 38. But 9mm is right at the same level of SAAMI pressure

JDinAZ · #**162** 05-09-2022, 11:43 PM

Quote:

Originally Posted by JimCunn

"But you did claim that the aluminum frame is fine for 357/9mm"

Post a quote, in context.
That said, I've noticed that so far, my three 637-2 titanium cylindered 9mm J-frames have incurred zero damage from 9mm. I have .357 titanium cylinders for them, but don't shoot .357 because 9mm recoil is painful enough.

Literally the whole past page man. And your post I just quoted where you asked me to quote you in context

Your endorsement of 9mm in aluminum j frames. You mentioned just above you have three aluminum j frames that are converted

Quote:

Originally Posted by JimCunn

"The 38 Spl is MUCH more powerful than 9mm if you can reload your own and not be beholden to what ammo companies make".

Wouldn't it be quicker and easier to just use over the counter .357Mag ammo if you want that much more power? It takes less than two minutes to replace the 9mm cylinder/crane assembly with the .357Mag assembly. I don't often do it because the 9mm recoil is painful enough to suit me.

This one you insinuate just swapping to a 357 cyclider because it’s easier

See my conundrum.

I could be wrong and like I said. I kinda hope I am wrong on this one. I’d love to run a dedicated cylinder conversion line in the shop. But I have a hard time going outside the approved frame rating from the factory

Screwball · #**163** 05-10-2022, 09:17 PM

Quote:

Originally Posted by Save Ferrous!

It is pretty amazing what a revolver can be called on to do. But if you can't fire the gun more than a handful of rounds before your hand is numb, you're not really setting yourself up to fight with confidence. So most of this just seems like exotica rather than practicality.

Having carried the same revolver in .38 +P, and then shot a LCR in .357 Magnum… I don’t consider 9mm to be excessive.

I shoot all my carry ammo yearly, which is a full box of Hornady XTP (standard pressure, 147 grain). Throughout the year, I practice with my stash of bulk UMC 115 grain… which has an identical POI as the Hornady (why I bought it in bulk). Both will hold crimps for the four rounds, but I did test Hornady with multiple cylinders, just for peace of mind (I did three four-round groups on the same test round… no bullet movement).

A 100 round range session isn’t hurtful, nor is my hand numb afterwards.

Maybe it’s me, as I grew up shooting .44 Magnum. Literally, 12 years old… shooting standard Magnum loads out of a 6” 629, not Specials. I have an M&P40C that I am planning on utilizing my new .357 SIG barrel once ammo somewhat stabilizes. But I enjoy shooting my 9mm 642.

Baltimoreed11754 · #**164** 05-10-2022, 11:04 PM

I had my scandium .38 spcl j frame cylinder cut for moon clips. Plus-P is more than sufficient in such a light gun to my thinking. 9mm would be a bear.

winchester62 · #**165** 05-11-2022, 12:10 PM

Quote:

Originally Posted by Save Ferrous!

I read the whole thread, and I'm the proud owner of a .38/9mm K frame conversion. And I really don't get why someone would bother with this sort of thing in a J frame. I understand that it is neato, and I see the ballistic argument. But they make .357 and .38 +P defense loads that should get you there - and they hurt enough in a really light revolver.

A five shot .38 may not be a cannon, but most folks would acknowledge that it is probably good enough. And if you like revolvers and like super light weight, an ultralight with .38 standard pressure seems like a reasonable compromise.

But if that isn't good enough, I just can't see the argument against just spending $450 on a Kahr CM-9 and being able to fire 7 rounds of hot 9mm from a platform with relatively little painful kick and accuracy similar to a J frame while being notably smaller. But maybe I'm looking at autos as being reliable enough and not convinced revolvers - especially ones fired much with heavy kicking ammo - are going to be any more reliable. (Bullet jump especially considered.)

It is pretty amazing what a revolver can be called on to do. But if you can't fire the gun more than a handful of rounds before your hand is numb, you're not really setting yourself up to fight with confidence. So most of this just seems like exotica rather than practicality.

As you say, some people might not prefer the conversion in a light J frame. How would you say the conversion is in a k frame? Pleasant? Between a 38 and 357? Would you do the conversion again if you were making the decision now? I'm a few days away from sending my 64 4 inch heavy barrel off if I don't change my mind. My motive is cheaper factory ammo and I like the idea of quick reloads too. Thanks for any feedback. I hope nobody minds the k frame creep.

HeyJoe · #**166** 05-11-2022, 12:33 PM

Quote:

Originally Posted by Save Ferrous!

I read the whole thread, and I'm the proud owner of a .38/9mm K frame conversion. And I really don't get why someone would bother with this sort of thing in a J frame. I understand that it is neato, and I see the ballistic argument. But they make .357 and .38 +P defense loads that should get you there - and they hurt enough in a really light revolver.

A five shot .38 may not be a cannon, but most folks would acknowledge that it is probably good enough. And if you like revolvers and like super light weight, an ultralight with .38 standard pressure seems like a reasonable compromise.

But if that isn't good enough, I just can't see the argument against just spending $450 on a Kahr CM-9 and being able to fire 7 rounds of hot 9mm from a platform with relatively little painful kick and accuracy similar to a J frame while being notably smaller. But maybe I'm looking at autos as being reliable enough and not convinced revolvers - especially ones fired much with heavy kicking ammo - are going to be any more reliable. (Bullet jump especially considered.)

It is pretty amazing what a revolver can be called on to do. But if you can't fire the gun more than a handful of rounds before your hand is numb, you're not really setting yourself up to fight with confidence. So most of this just seems like exotica rather than practicality.

the same argument you present can be used against your converting a k frame to 9mm. People do it because it is possible and they want too, just like you did, no further justification needed.

JimCunn · #**167** 05-12-2022, 02:43 PM

May not be practical, but I have three of them.
I usually carry with the 9mm cylinder.