Converting J frame to shoot 9mm

[JimCunn]

"Man, for that I would have just bought a reloading press"

I've got several reloading presses and have been reloading since the 1960s.
If you count labor, reloading is much more expensive than over the counter purchases. As I grow older, I reload less.
Moon clips are much quicker and easier to handle than speed strips. They are one of the major enhancements of the conversion.

"if you can reload your own"

I can, but would rather spend my free time behind the stick of antique taildragger airplanes.

You can also jack up the power of 9mm, but why punish your hand?

 

[JimCunn]

"A long (sad for me) story, mostly concerning a converted cylinder and crane that needed to be re-fitted to my 442 (and, apparently, to any other J-frame other than the original "donor" assembly to be sent in).....,"

Yeah. It usually takes me 15 minutes to an hour per cylinder to do that. I do it while watching television.

I buy used J-frame cranes on e-bay. They are sometimes warped, and I have to straighten them - but that goes pretty rapidly as well. I usually buy new titanium center pins to get the weight down a bit more. They are .357Mag, and I have to shorten them a bit to fit. I use titanium cylinders for the same reason. In the back of my mind, I've been thinking about hollowing out the grips and removing some material from inside the frame for the same reason.

Depending on the grips, I'm presently at 11.5 ounces to 12.5 ounces for my 637-2 J-frames. I'd like to shed another ounce.

I also rework my actions to provide about a 3.5-4 pound double action trigger pull and 1 pound single action. I smooth up the Internals but don't mess with the sears.

 

[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.

 

[Rock185]

I was just reading through this interesting new/old thread. I've said before that I like the 9mm cartridge and 9mm revolvers. But, I realize most revolver shooters would probably prefer revolvers chambered in traditional rimmed revolver cartridges. I get it. I have revolvers chambered in those traditional rimmed cartridges too.

I can't offer much in the way of argument that 9mm revolvers are better than .38/.357 revolvers. I've had other 9mm revolvers, and still enjoy shooting a 940, SP101 and, not a converted J-Frame, but a converted 686. Can't justify converting the 686 on any rational grounds, other than it's just hobby stuff I felt like doing. If all my hobby stuff had to have some practical purpose, I guess it wouldn't be a hobby anymore

Amusingly perhaps, the 4" 686 9mm conversion often as not produces velocities lower than the little 2" 940. For instance, a favorite carry load of mine, the Federal 124 +P HST, produces 1195 FPS in the 2" 940 and only 1012 FPS in the 4" 686 conversion. IMI 124 NATO ball produces 1079 FPS in the 2" 940; a lackluster 1077 FPS in the 4" 686 conversion. Other ammunition tested produced similar results. All that generous freebore in the cylinder before reaching the cylinder throats I guess. I sure can't claim those results are very practical...

 

[reccpd101]

I'm just now venturing into converting a 360 J frame to 9mm using a Model 60 357 cylinder. All my converted K & L frames have used 38 or 357 cylinders converted by Pinnacle. I have been very pleased with them.

I'll post an update when completed and range tested.

 

[winchester62]

I just bought a police trade in 64-5 and a spare cylinder and crane off fleabay with the intent of having a revolver that is convertible to 9mm. Eventually it will pay for itself due to the cost difference between factory 9mm vs factory 38 special. I could reload and probably will one day, but for now I'll just shoot the heck out of this thing if I manage to get it done. My good friend and shooting buddy thinks I'm wasting my money. One of us might change our mind after it's all said and done. Time will tell.

Edited to add: I know this is a J frame thread, but I thought it would be ok to throw in a little K frame 9mm conversion action too.

 

[JDinAZ]

"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.

Correct it is simple to swap cylinders.

IF you are using a magnum frame. Steel stainless or scandium

It is worth noting that (not to my knowledge) smith has never made an aluminum framed 357 j frame gun.

If the aluminum J frame smith could, by smiths determination handle magnum pressure loads, from a manufacturing standpoint smith would make an aluminum j frame 357 and offer it to the public. It costs less to manufacture a gun from aluminum than it does steel stainless or scandium.

The aluminum framed J is not engineered to withstand magnum pressures. Which 357 and 9mm are neck and neck on SAAMI pressures

Swap or conversion in a J that began life as a 357 magnum would be within the manufacturers engineered frame strengths

Swap or conversion of an aluminum J 442 642 438 638 et al would exceed the frames engineered abilities

 

[PALADIN85020]

I've been shooting .38/357 and 9mm out of the same gun for years. No problem at all.

John

 

[Screwball]

Swap or conversion of an aluminum J 442 642 438 638 et al would exceed the frames engineered abilities

Well, quite a few of us have been doing it for some time… so can’t argue track record.

I mean, if you look into 9mm conversions of J-frames… you get threads back to 2009. I’ve yet to see one that failed or even caused an issue.

The member I spoke to prior to converting my 642, who was one of the original converters, sold his and knows the guy who bought it… he still shoots it.

 

[JDinAZ]

Well, quite a few of us have been doing it for some time… so can’t argue track record.

I mean, if you look into 9mm conversions of J-frames… you get threads back to 2009. I’ve yet to see one that failed or even caused an issue.

The member I spoke to prior to converting my 642, who was one of the original converters, sold his and knows the guy who bought it… he still shoots it.

That may be. But will smith issue you a letter stating that you can use a 357 cylinder and 357 ammo in a 38 or 38+p j frame. No they won’t.

People can do what they want.

But the fact remains you should not run a 357 cylinder with 357 ammo in a 38+p rated frame. Running 9mm in a 38+p frame is the same equivalent SAAMI pressures as 357 which is what ratings get based on

Would you endorse and take responsibility for someone running a 357 cylinder and ammo in a 38+p frame.

Failing to make the distinction between the frame ratings is a valid point to bring about. Many new gun owners should not be mislead that they can swap a 357 cylinder onto a 38+p frame safely

 

[JimCunn]

"Many new gun owners should not be mislead that they can swap a 357 cylinder onto a 38+p frame safely"

Many new gun owners should not be allowed to tie their own shoe laces.

 

[JimCunn]

"Many new gun owners should not be mislead that they can swap a 357 cylinder onto a 38+p frame safely"

Why did S&W enlarge the Airweight J-frame windows to accept .357 cylinders?

 

[JimCunn]

"But will smith issue you a letter stating that you can"

Corporate lawyers don't allow issuance of letters saying you CAN do anything.

 

[JimCunn]

"The aluminum framed J is not engineered to withstand magnum pressures".

How do you know that? Are you now, or were you ever a design engineer on S&W Staff?

 

[JimCunn]

"People can do what they want".

Thank God.

 

[JDinAZ]

"Many new gun owners should not be mislead that they can swap a 357 cylinder onto a 38+p frame safely"

Why did S&W enlarge the Airweight J-frame windows to accept .357 cylinders?

Very simple. So they didn’t have to make two different frames. One for 38 only. One for 357.

If the aluminum frames were rated for 357 they would stamp 357 on the barrels and sell low cost 357 at the same price within a couple bucks of the 38 only guns and corner the market with it

 

[JDinAZ]

"The aluminum framed J is not engineered to withstand magnum pressures".

How do you know that? Are you now, or were you ever a design engineer on S&W Staff?

See last post

If the aluminum in smiths engineering opinion would handle 357. They would just chamber them all for 357 since you can still use 38 also. There would be no need to manufacture a 38 only marked j frame

Less cost for aluminum frame. Conquer affordable pocket 357 and 36 market with one gun

 

[JimCunn]

"If the aluminum frames were rated for 357 they would stamp 357 on the barrels and sell low cost 357 at the same price within a couple bucks of the 38 only guns and corner the market with it".

Would they? It's a small market - 9mm and .357 recoil is painful in a 12 ounce revolver. You gotta be willing to accept that if you're gonna shoot one. Most people don't appear to be willing to do that. Easy to lose money catering to a small market. Has nothing to do with safety.

 

[JimCunn]

"Less cost for aluminum frame".

How much less?
Quantify it for uss.

 

[JimCunn]

"Swap or conversion of an aluminum J 442 642 438 638 et al would exceed the frames engineered abilities"

Do us all a favor and post the calculations demonstrating that.