I have a soft spot for 3" .357 Magnums as they seem to be the sweet spot for concealed carry balancing conceal-ability with reasonable ballistic efficiency if you choose the load well.  

I found a S&W Model 13 in the 3" round butt heavy barrel FBI model in the local gun shop at an excellent price due to some carry wear.  While it's been carried a bit it appeared to have very few rounds put through it with very tight lockup, minimal end play, no end shake, and an excellent trigger that is crisp and clean and breaks at 3.5 pounds in SA mode and somewhere slightly north of 9 pounds in DA mode.

The standard grip was well suited for concealed carry and was fine with .38 Special loads, but wasn't comfortable to shoot with .357 Mag loads.



I tried a Hogue Monogrip on it, as I like them on my J-Frame S&Ws.  It was quite comfortable with .357 Mag loads, but it didn't work well on the this K-frame as the left side of the grip interferes with the speed loader.


Another local gun shop had a Pachmayr Compac grip for a round butt K frame and it turned out to be ideal for the Model 13.   It's small enough to conceal well on the  Model 13, given that it's bordering on the large size of conceal-ability with  a larger grip. It also works very well with my Model 10 HKS speed loaders, and stress fire style reloads are quick and positive.  



The Pachmayr Gripper grips on my 2 3/4 Speed Six push it over the edge size wise and unfortunately, it's the only grip Pachmayr makes for the Service/Security Speed Six models, and they no longer catalog a grip at all for the round butt Speed Six.






------

With the Pachmayr Compac grip installed 150 rounds of .38 Special  158 gr LSWCs were very pleasant to shoot and the 50 rounds of my .357 Mag 125 gr self defense load were 'sporty' to shoot, but didn't cause any discomfort over the entire 50 rounds.

As noted above the trigger is excellent on this revolver and while the DA pull is somewhere slightly above the 9 pound limit on my trigger pull gauge, it stages extremely well and is very predictable, giving excellent control in releasing the shot when the sight alignment is perfect.

I started at 7 yards shooting double action where it kept 12 rounds inside the X ring on a B-27 target offhand, with an isosceles stance.  At 12 yards it held the 10 ring with 10 rounds with a couple of rounds just into the 9 ring (and I suspect they were my fault).  At 25 yards it held the 9 ring primarily, with again a pair of holes that drifted just into the 8 ring (and again I suspect it's the shooter responsible for that.   Not bad for offhand, D/A mode shooting.

I expended 12 of the remaining 14 rounds in the box drawing and shooting failure to stop drills back at the 7 yard line where at speed it still held the 9 ring for all 8 rounds for the first two shots and all 4 rounds for the head shots.

I proceeded with the 150 rounds of .38 Special LSWC loads and found the accuracy was, not surprisingly, even better.  The rear sight is a bit narrow and I suspect if it were opened up just a bit, it would demonstrate slightly better accuracy.

I finished up with six rounds with 20 grains of Win 296 under a 125 gr XTP - a near maximum load and my preferred Model 92 load - and the recoil was still comfortable, although (typical for heavy loads of 296 in a short barrel .357 magnum revolver) it pelted the left side of my face with powder grains on every shot.  

----

In short, it looks like a concealed carry winner and I've ordered a Covert Carry IWB holster for it from the folks at Wild Bill's Concealment down the road an hour or so in Garner NC.

Nice write up, I just finished up a 3" Colt Agent project to do what your revolver does. Shoot 38spl +p, be easy to carry and shoot well. Nice find!

Love mine! The previous owner seemed to just shoot .38's in it as I had a heck of a time getting out the residue
in the cylinder. It's my favorite atv'n and woods bummin' revolver. Usually it's stuffed in an equally old Bianchi crossdraw holster.

ETA: Dang it if those shooters don't look exactly like 2 I've seen on another forum.

I like the Compact Professionals on snub K's

I had my 4" square butt Model 65 converted to a a 3" round butt version several years ago. It is a great carry pistol......

Who did you have do the conversion?  Mine is an old run of the mill police gun and I've had several people tell me they won't do the round butt conversion because the serial number is on the bottom of the grip.  I know it was a popular conversion at one time so not sure why folks don't want to do it now.  I also want the barrel cut to 3" and maybe slabbed like the old Super Ks.

FBI "model" as a moniker but hopefully not a FBI model 13.  Some went to the MN state police and others.

Why the note?  At the end of revolver issuance, the agents were offered their revolvers at USGov original purchase prices from S&W.  $72-75 each.  Often for brand new virtually unused guns.  Smarter agents using semi auto pistols, but having no revolver, got a NIB 13 issued to them.

BUT, ALL of the 10-6, 10-8, and 3" 13s were collected from agents and destroyed at the insistence of GSA.  GSA decided the USGov could not trust working agents in the late 1990s to purchase a 6 shot "weapon of mass destruction" as originally intended.  The same people now carrying Glocks and SIGs.  

Sales canceled.  Guns recovered.  Turned in. Destroyed. Any "FBI" revolver of this variety in the wild is stolen.

Here's my nickel plated Model 13.

Yup.... the only reason why FBI 1076 pistols are in the wild is because S&W actually bought them back from the Feds. They weren't FBI property at the end of it all. They were back to being S&W property.

 

The Model 13s were all Fed property and were Captain Crunched.

I had it done many years ago by a gunsmith down in Alamogordo, who sadly is no longer in business. I think he did only around 9 or 10 of these conversions before he retired. As for the serial number issue, I brought a set of RB grips with me for him to use as a template and it didn't affect the serial number on the grip at all.....

Yep.  Sad one.  I had a brand new NIB 13 3" issued to me.  Never even bothered to fire it since it function tested perfectly.  Taken back and destroyed.  The worster thing was I had a couple friends that didn't want their 10-6/10-8s because $72 was too much to waste.  I was just going to buy theirs for spares after they shuffled the paper.  

The GSA actually called them a weapon of mass destruction and claimed the liability for selling them to the same agents that carried them was so onerous the USGov could not afford the chance an FBI agent would go Postal.  And here I thought the USPS was a separate corporation.

Smith bought back the 1076s because they were turning into junk since the silly agents actually fired them 8 times a year for practice rather than just buying them and loading them and putting them into a nightstand which is where most Smith products end up.  Actually had a Smith rep tell me that, that they were shot too much.  My goodness, a solid steel heavy auto fired with a pussy cat mild load like a light loaded .40 in a 10mm case.  The production line 1076s were really bad from the get-go.  The replacement set of Custom Shop 1076s mostly worked fine for a few thousand rounds and then did the same thing as the production line guns:  i.e., every know fubar.

I signed for the shipment of Custom Shop 1076's, sorted through 25 of them in the case, picked the one with the best trigger NIB, and assigned it to myself.  Fired it one training day.  Too damn heavy to carry around.  Cleaned and put away till junked.  Just keep using my SIG P220.  At least my pants were not lopsided.  Happily replaced that with my personally owned Glock 22 that made it through the factory order and Quantico check months faster than the issue 22s.  So I kept my own when I retired.  Been running ever since.  Absolute Perfection for 19 years so far.

As a practical matter, the coolest FBI revolver was the Office of Naval Intelligence hand me down to SWAT guys Smith 19s that were a 4" factory round butt.  They were also crunched at the end.  I had my own version made in 1975 except it was a 4" M66 that Davis or Bain&Davis in California re-did into a round butt.  Most perfect revolver I have ever owned.  The round butt K frames shot 147 +P+ .38 HydraShok and 148 wadcutter and 158 loads to different points of impact sufficient that adjustable sights were a good idea.

Alas..... California used to be such a great place for guns. Sucks what happened there and also what happened to the FBI guns. Revolvers in general are fantastic guns when done right and the day of well done wheel guns are coming to a close.

Nice looking revolver OP.....if it were mine I would send it off to Metalife and have it hard chromed.

MIC...your 65 was the inspiration for my 681 that I roundbutted and cut to 3".......there's a pic of it on here somwhere. Always loved your 65.

Hell yes.  I want one of these bad.

 
Love 3 inch wheel guns....





My Model 13 and GP100 with the compact grips





US Postal Inspector Contract Gun





Model 65 Factory DAO

Thanks! It's been a great carry gun. It was one of three that I built when I went through the S&W Armorers course back in the early 80's. Each of the students were allowed to buy one of the guns they built for around $70.00 or $80.00 As I recall.

A round butt 681would be an awesome carry pistol……I would love to see pics of that beauty…

OP, sent you an IM about grips for your Ruger.

Really nice revolver  

Be careful shooting hot 125gr magnums in the K-frame

It's hard on the forcing cone

...and S&W isn't making replacement barrels anymore  

Ask and ye shall receive. Novak tritium front sight and Tyler adapter....but it now sports some vintage Magnas.

I appreciate the concern, but it's not the 125 gr bullets that cause the problem and I'd like to put that myth to bed, or at least put it in its proper context.

Unfortunately, people have massively over simplified the issue and blame 125 gr bullets when they are not the major cause of the problem with forcing cone erosion and forcing cone cracks in K frames with high rounds counts of .357 magnum ammo.  

There are several factors involved, but the primary culprit is the powder used.

The design of the Model 19

Like the Model 19, the Model 13 was really designed to be carried with .357 Magnum but primarily shot with .38 Special. That's an artifact of the days when law enforcement agencies had their officers practice with .38 Special but carry .357 Magnum.  The Model 19 was designed around that practice and was never intended for a steady diet of .357 Magnum ammo.  

The forcing cone in the K-frame .357s is fairly thin and it's thinnest on the bottom side due to the machining that was done to provide clearance for the crane. High round counts of .357 Magnum loads tend to produce throat erosion.  Those  little V shaped cuts in the throat create stress risers that can cause cracks - particularly in the lower portion of the forcing cone where the metal is thinnest.

The 125 gr bullet theory

The popular belief is that the erosion and cracks are caused by the use of shorter, lighter bullets, and the theory is that the shorter bullet allows hot gasses to flow past the bullet as it leaves the case and then preheat the forcing cone before the bullet arrives, making the metal for prone to erosion.

That's not quite farm animal stupid and on the face of it is sounds both logical and plausible.  However, the theory doesn't hold up to any serious consideration of the thermodynamics involved as the time available is so short that no significant heating could occur - yet this short bullet theory and accompanying explanation get repeated so often that people regard them as facts.

There are also historical roots for the belief.  The association between shorter bullets and cracked forcing cones has its roots in coincidental development of 125 gr .357 Magnum law enforcement loads that replaced the older 158 gr law enforcement loads at the same time that police departments started getting sued for under training officers.   The result of the lawsuits was changes in training practices and most police departments with officers carrying .357 Magnum ammo switched from practicing with .38 Special to practicing with .357 Magnum. At the same time in response to the general concern for under straining officers, many departments started shooting more practice rounds.   So, at the same point in time, you have 125 gr .357 mag loads coming to into use, along with the use of .357 mag loads for training, and an increase in training rounds fired - all in a revolver that was designed to be primarily fired with .38 Special  

The end result was that the Model 19, a revolver designed to be shot with .38 Special and carried with .357 Mag, was instead being shot all the time with .357 Mag ammo. The occurrence of cracks in a small percentage of Model 19s wasn't all that surprising.  However, because the load being used was usually a 125 gr .357 Magnum load, the shorter bullet got all the blame.  

What really causes throat erosion in the .357 Magnum

The major factor in throat erosion in the .357 magnum - and one that is almost totally ignored - is the use of slow burning colloidal ball powders in many full power .357 magnum loads.  There are two related internet myths that just won't die that come into play here.  

First there is the belief that all powder is burned inside the case, even with slow burning colonial ball powders like Win 296.   The fallacy of that is easy to demonstrate to shooters, but even when you do many of them refuse to believe it, because they have heard it so often and buy into authoritarian arguments, even when evidence to the contrary is literally hitting them in the face.

For example if you read my original post you'll note I shot 50 rounds of .357 mag loaded with a maximum load of a flake powder (9.0 grains of Unique) with no powder being thrown in my face, yet each and every round of 296 loaded ammo did exactly that. Clearly the powder isn't being fully burnt, and that large charge of hot, abrasive powder is flowing through the forcing cone at over 1200 fps.  Shooters however will start blaming the revolver's timing, or leading of the forcing cone, etc, to explain the problem and never realize it is the powder being used that causes the problem.   Why?  Because many of them believe the myth that the powder is all burned in the case.

Second, there is a belief that maximum loads of slow burning powders will produce maximum possible velocities even in short barrel .357s.   I suspect this myth is a follow on to the theory that all powder is burned in the case, even with slow burning colloidal ball powders like Win 296.   That's probably bolstered by the accurate perception that felt recoil is just as high or higher with these large charges of slow burning powder than is the case with faster burning flake powders and in the absence of actual chronograph data, the shooters are using felt recoil as a measure of velocity.

Sadly, they believe this so strongly that even when you show them chronograph data to the contrary they'll refuse to believe it as it does not agree with their perception of the felt recoil.   What these shooters don't understand is that powder has mass and when that mass acquires velocity it creates additional recoil.  They also don't understand that the propellant gasses exit at a muzzle velocity about 3 times faster than the bullet's muzzle velocity, creating more recoil than you'd expect for an extra 10-11 grains of slower burning powder.  

Fast versus slow powders in short barrel .357s

The 9.0 gr of Unique load mentioned above generates 1296 fps average velocity in a 3" barrel with a standard deviation of only 17 fps - based on extensive chronograph data. It's not only producing high velocities for the barrel length, but it is also doing it very consistently.   In comparison 20 grains of 296 under the same 125 gr bullet will produce an average velocity of only 1148 fps with a standard deviation of 35 fps in the same 3" barrel.   Yet despite the velocity being 148 fps slower the felt recoil is very similar.

The major difference is that with 296 you have 11 grains more partially burnt powder and gas exiting the barrel at about 2-3 times the muzzle velocity of the bullet, creating more recoil.  As a self defense load, 20 grains of 296 under a 125 gr bullet makes no sense in a 3" barrel, as you get just as much recoil but less velocity.  

Where I use that load is in my 20" and 24" Model 92s where is produces 2,170 fps and 2,210 fps respectively with standard deviations of around 15 fps.   Win 296, as a slow burning colloidal ball powder, shines in .357 rifles and carbines where the slow burn rate can create a high pressure differential driving the bullet through the entire bore.    You'll also see the advantage in 6": and 8" .357s where again the longer barrel allows more efficient use of the slower burning powder.

Where lighter bullets do come into play

When you are using a slow burning colloidal ball pistol powder like 296 or a flattened spherical powder like 2400, lighter bullets equate to larger powder charges.  For example with a 125 gr bullet you have a max load of 20.0 grs of 296, compared to only 16.0 grains with a 158 gr bullet.  That's 25% more powder in the 125 gr load compared to the 158 gr load, and 25% more heat as well as more potential erosion per shot as the larger charge and increased heat in the 125 gr load creates more partially burnt powder flowing through the forcing cone, increasing forcing cone erosion.

You don't see that in 110 gr loads as those same slow burning ball powders don;t have enough efficiency so they don;t get used much and thus that leaves the 125 gr bullet holding the bag - when it's really the powder at fault.  The bad news of course is that all those shooters using a slow burning ball powder in with 140-158 gr bullets in their .357s are unnecessarily increasing throat erosion by using that powder, but think they are safe as they are not using 125 gr bullets.  And if they crack a K-frame forcing cone, they'll still blame it on any number of 125 gr bullets that might have bene shot in it in the past.  

In summary

It's not the bullet but the powder that is doing the damage and if your .357 magnum load is hitting you in the face with partially burnt powder it's also eating your forcing cone as that hot abrasive powder is flowing through it.  Smaller charges will reduce the rate of erosion, and larger bullets will have smaller charges, but it's still the powder doing the damage - not the bullet.

My advice then, particularly in barrels of 4" and shorter is to stay away from colloidal ball powders and flattened spherical powders as you gain little or nothing in velocity, and don't worry about the bullet weight.  

Also if you're shooting commercial ammo and it is hitting you in the face with powder grains, switch to a different load that doesn't as that powder will be eroding your forcing cone.  

Forcing cone erosion is less likely to lead to cracks in larger frame revolvers due to the thicker forcing cones, but it's still not a good thing, particularly if you shoot a lot.

Lotta words and interesting theories and facts.

A side issue in K frame Smiths is the 1990's LEO +P+ .38 special ammo for which there is no SAMMI spec.  A LE Agency designates the bullet and velocity, waives all ammo factory liability, and Federal or WW produces the desired product.  The LE agencies intended the +P+ ammo to be loaded in .38 Special cases to at least .357 performance AND be used only in .357 revolvers.
 
Federal in the 1990's had a USGov contract for +P+ .38.  They loaded it so it was only at the upper +P pressure range but put it into +P+ headstamped .38 cases. Mildish pressure with full desired velocity.  147 grain HydraShok bullet identical to the 9mm 147 HydraShok loading for the same agencies.  Federal engineers are fairly smart.  They regretted the +P+ headstamps because they could have sold tons more as +P .38s.  Word from Federal engineer to my ear.

WW is/was not so smart.  They bid on the same contracts.  They used a 147 grain bullet at the same velocity, but the pressure was off the scale.  A C or D serial number Smith Model 10 soon split the cylinder, who cares about the forcing cone.  The same idiot ammo split and broke K frame Smith .357s and had to be withdrawn.  Looking for something to do with it, guys tried it in N frame .357s.  OK, but noisy.  They tried it in Rossi carbines and split the barrel/ chamber.  What of that stuff that escaped into the wild, wrecked a lot of guns.

The words a post up can discuss .357 ammo to death.  It was mild stuff compared to the far more common and worrysome  "its only a .38" bullshit a lot of LE agencies tried to claim as not being the dreaded "magnum."

I'm not sure how this is relevant to the 125 gr bullet issue, and I don't understand the point you are trying to make.

There's a long history of loads operating at much higher pressure than standard .38 pressures going back to the .38/44 which was the inspiration for .357 magnum development.  Aside from the .38/44 which was designed for large frame revolvers, there have been numerous law enforcement only loads in the .38 Special case adopted before and after the .38 +P standard was adopted by SAAMI in 1972 that were well over .38 +P pressure.

Some of these ".38 Special" loads were operating at pressures as high as 30,000 psi and were effectively mini .357 Magnums.   These loads were usually an attempt field a .357 Magnum  revolver chambered in .38 Special, but with .357 Magnum performance in order to avoid the negative press and politics of the agency using the .357 Magnum cartridge.  The agency involved could have officers carrying revolvers chambered in .38 Special shooting using a .38 Special cartridge but at or nearly at .357 magnum pressures.

But none of these rounds were ever intended to be shot in older Model 10 revolvers.  The Model 19 was more than just a K-frame revolver with K-frame dimensions, the steel used was stronger to allow higher pressures of the .357 Magnum.

well,  I've been handloading .357 with H110/w296 and UNIQUE ( aka combustible dirt ) since the 1980's

i use 22grs H110 for 125gr,...but don't own any 3" magnums

in my 4", 5", and 6" they chrony more velocity than unique

i also run them in a 16" carbine  

I've heard different theories,.....and have seen model 19's with cracked forcing cones

so I limit there use to L-frame revolvers

That's a pretty gun. Sure makes the Ruger look like a mutt.

Those grips are ugly but comfy.

Mine are a little stinky yet, too. I've got a set on my M67.

That is a beauty!

The silver T-grip looks great. I also have a Model 64 with the thin profile (Pencil) barrel that I would love to put a T-grip on……

Lotsa theories about guns and ammo.  Lotsa theories in the one post.  I made some parallel personal observations.

Note that those 10-6 and 10-8s were only grudgingly admitted by Smith to be safe with .38 +P at the time, yet were fed a steady diet of +P+.  Thankfully mostly the Federal version, not WWs or the Secret Service 125 version.

The 13s were .357s.  Maybe a biggie or maybe not.  The 19s and 66s were .357s also.

One problem with theories is that stressed K frames didn't ordinarily split cylinders or forcing cones.  More common damage was that the frame window stretched until headspace exceeded the firing pin length.  A gradual process.

.357 factory SAMMI ammo was being de-tuned over two generations.  Some of the +P+ stuff exceeded the then in use .357 as time went on.

While a K frame .357 sometimes split forcing cones, Gawd knows how much of what ammo was fired in those guns before failure.

Some of that LE ammo should never have been loaded.

I will say the Fed 147 +P+ was the most accurate ammo I ever fired in a handgun.

Controlled Chaos Arms of Baxter, IA has done several of these. They have machined the barrel sides into flats and remark them as 357 Mag. They also did something similar for me on my Travel Gun, see the thread elsewhere in this section.

Here is a 4" that they did for me, I may have this one converted to a 3":

My first run S&W Performance Center "F comp":













 

Wish I could put a FO front sight on all my fixed sight K-frames. Not many people doing this sort of work these days.

The Guards (no police authority off campus) at the Federal Agency I work for stored their wheel guns for years after they switched to autoloaders; one day about 15 years ago they contacted the department I worked in at the time about destroying the revolvers as no other Fed. Agency wanted them. My boss made me set them up and split them long ways with a plasma torch. I cut up 36 handguns that day two .32 K frame S&W's, 2 Colt Detective Specials, and the rest Mod 14's&15's and pre number K frames all in .38 special. It was the worst day I have EVER had at work. At that time I figured it was about $ 8-10K worth of guns, who knows the value now.  I recall the property custodian got pissy because I insisted on opening the cylinder on each gun and checking to make sure it wasn't loaded.



 

3" K-Frames are cool. A few years ago I found this lightly used Model 65-5.



Shortly after I bought it and took this pic, I went to S&W's website and ordered one of the last pairs of Uncle Mike's boot grips they had in stock. The gun is sitting in a lock box in the end table next to me, loaded with Remington .38 Special +P 158 grain LSWCHP "FBI Loads."