Converting J frame to shoot 9mm

[zogger]

I am considering having TK Custom convert my Model 60-14 3" to be able to shoot 9mm along with 38 Special and 357 Magnums. Has anyone had this conversion done and how did it work out for you?

Thanks!

 

[JimCunn]

I've done it to three 637-2 airweight J-frames, using titanium cylinders and center pins to reduce weight (12.5 oz).
Works great, with good accuracy.

 

[326MOD10]

Had TK Custom do a 360J cylinder and an older Model 60 unfluted cylinder for me.

Both work well and the work was top notch.

 

[cleans up]

I have a 340 that was converted to accept 9mm up to 9x23 (IIRC, I've never shot anything but store bought 9x19). One of my few true keepers.

It's a great mod, chances are you'll not only love it, but if your a higher volume shooter who doesn't reload it can pay for itself.

DO IT!

 

[JimCunn]

It's also much faster to reload.
I keep three extra moon clips in a Walmart pill bottle.

 

[cleans up]

It''s also much faster to reload.
I keep three extra moon clips in a Walmart pill bottle.

I'm curious who you found to machine the titanium cylinder. My understand was that in general only the steel cylinders can be modified. I know that's not technically true but I couldn't find anyone one when I searched a few years ago. I thought (assumed) it might be due to the higher case pressures of 9mm vs the difficulty of machining titanium, but I could be wrong.

 

[DonD]

Have no background on this conversion but one might think that shooting a round that's .355 out of a bore that's .357 would result in a good bit of blowby past the slug. Don

 

[Mike SC Hunter]

Have no background on this conversion but one might think that shooting a round that's .355 out of a bore that's .357 would result in a good bit of blowby past the slug. Don

And I wonder why too?

 

[mikerjf]

Anybody check for crimp jump in the lightweights?

 

[JimCunn]

TKC did my three titanium cylinder conversions (I think they may have since quit doing them). My last one was done about six months ago.
With the titanium cylinder and the Altamont combat grips, the 637-2 weighs 12.5 oz.
No crimp jump with 147gr 9mm JHP - I haven't tried .357 mag in them, and don't intend to, even though the peak pressures are the same and projectile weights are similar. Muzzle energy for the 147gr 9mm conversion with 1-7/8" barrel averages 292 ft-lb if I remember correctly.
No blowby or accuracy problems, the J-frame 9mm & .38Sp barrels reportedly have the same land diameter (that has been addressed here before, by others).
With the titanium cylinders, I do need to keep projectile weights above 120 grains to inhibit cylinder face erosion.

 

[cjtraining]

Is there an advantage to convert a j-frame to shoot 9mm?

 

[JimCunn]

Several reasons.
9mm is more powerful than .38Sp+P.
Most of my other pistols are 9mm.
Cause I could.
9mm is cheaper than .38Sp, but you'll never shoot enough of it to pay for the conversion.

 

[Qc Pistolero]

Both the .357 and 9 mm operate at over 30K PSI pressure while the .38 +P will do it at a tiny bit over 20K PSI.
If the gun can take .357 pressure it will take 9mm pressure.But dimensions both in width and length of the hole to be drilled in the cylinder might be problematic.Besides,performancewise,the 9 is quite limited in bullet shape and weight compared to the .38.
And if you, like I,are a believer in penetration,the .38 has a lot more flexibility than the 9(9mm max 147gr;.38 you can go up to 200gr while a 158 to 170 gr will offer optimum in an agressive SWC shape).
As a conclusion,financially speaking,I'd say that your money would be better invested somewhere else than this conversion.

 

[Gamer]

The idea 9mm in a small frame wheel gun appealed to me for the increased Velocity presviuosly mentioned. I bought a Ruger LCR and tried it out. With target ammo I did experience crip jump more than once. I believe it was Winchester white box and some American Eagle. However, with Hornady and Gold dots dots I did not have an issue. I have since purchased some HST in volume to test as a carry load when I get back to the range.

 

[The_Truth]

Truly pointless unless you're a 9mm fanboy

 

[JimCunn]

Helps if you like your bug to use the same ammo as your primary.
In a airweight, also gives a lot more power than .38SP+P without the severe recoil of .357Mag.

 

[malph]

Helps if you like your bug to use the same ammo as your primary.
In a airweight, also gives a lot more power than .38SP+P without the severe recoil of .357Mag.

I know this used to be true. Is it still true? .357Mag is a really flexible round depending on powder and projectile chosen.

Aren't there 357Mag defensive loads now that are designed to be used in shorter barrel revolvers?

I think this idea of converting tevolvers to 9mm has become a "because I can and want to" exercise. Nothing wrong with that. Freedom is great.

 

[JimCunn]

"As a conclusion, financially speaking, I'd say that your money would be better invested somewhere else than this conversion".

No argument there, but since my three 637-2 airweights each have three cylinder and yoke assemblies (original unmodified stainless, unmodified titanium .38Sp/.357Mag, and titanium 9mm conversion), I don't see financial investment as a consideration. I do confess that I am somewhat overrun with cylinders and yokes.

BTW, I use 158gr .38Sp and 147gr 9mm.
Not much into .357Mag in a 12oz gun.

 

[Marshal Tom]

I had considered it in the past but also just having my M&P 340 cut for MOON's for faster reloading of .38's. I realize that the shorter and in most cases more rounded configuration of the 9mm would likely feed easier. Have any of you done that or purchased a revolver already cut for moon clips and how well does that work?

 

[JimCunn]

"Freedom is great".

True 'nuff, it is.