So what is a good .357 round for an M66

[flip180]

I have been doing quite a bit of searching and have found that the M66 shouldn't be shot with a steady diet of .357 due to structual insufficiency. I have gathered that 110 and 125gr. rounds should be avoided. It will see alot of .38 ammo also but, I want to shoot a regular diet of .357 out of it also. I get the feeling that I might as well keep the GP100 for steady .357 magnum range use and use the M66 for a mix of .38 and .357 loads. Who here has shot their M66's enough to exploit this problem or is it a matter of "well, I heard somebody say" kinda thing. I'm fixing to get into reloading my own range ammo and want to standardize bullet weights for my .38 and .357 for use in my 642, M66 and quite possibly GP100.

Thanks, Robert.

 

[Lone Star]

Robert,

You just answered your own question. Use .357 enough to stay familiar with how it shoots in your M66, and shoot most of the .357's you fire in the GP-100.

I've owned seven M19's and 66's over the years. The M66 four-inch I bought in 1990 is one of my most treasured handguns, ever. I've carried it almost daily in my security job. It is an excellent blend of balance, appearance, fine trigger action, power and weight.

I load it with .357 Hydra-Shoks for duty or when camping in wild country, and with lead HP .38 ammo when working indoors or in thick crowds.

I've owned heavier guns, and am about to replace a GP-100 I sold due to quality control issues. I love N-frame and M686 S&W's as well as anyone, I think. But for a daily carry gun that also makes a good hiking/traveling companion, I think the M66 is the best sidearm yet.

Truth be told, one shouldn't fire .357 ammo routinely. It's hard on ANY gun. You only need it for gunfights and for animals too large to kill cleanly with .38 Special rounds. Most people shoot a lot more jackrabbits than they do deer! Coyotes are about where you need to step up to .357 power.

Lone Star

 

[flip180]

"You just answered your own question. Use .357 enough to stay familiar with how it shoots in your M66, and shoot most of the .357's you fire in the GP-100."

I hate it when I do that:banghead: . Maybe I'm looking for a reason to keep the GP100 and not sell it to recoup the money I paid on the M66. I had it out today and set it out next to the M66 and my 642 and even though it is a Ruger and not an S&W, it is still and brickhouse of a gun.

Robert.

 

[Jim March]

What's your barrel length in the 66, and for that matter both other guns?

I ask because the Gold Dot 158grain 357s loaded to about 1,250fps in a 4" tube is a great load from a 4" or 6" barrel, decent in a 3", *maybe* problematic in a 2". It's less wear'n'tear on the gun than the hottest 125grain loads like the Remington and Cor-Bon.

As a 38spl+P lesser load that'll print about the same place, the Remington or Winchester 158grain LSWC-HP+P are marginal in a 2" (about 850fps depending on the gun), will work great in a 4"+. Bufallo Bore's upcoming version is supposed to be hotter, at 1,000fps from a 2" and would be a really good alternative for steel-frame guns that you don't want to run at full 357 horsepower.

 

[flip180]

The GP has the 4in heavy bbl with the 66 having the 2.5in bbl.

Robert.

 

[gyp_c2]

hmmm...

I don't know what loads you are planning on using but I put over 5000 rds through my 66 with no problems what-so-ever...That was a compressed load of 296 under a 125 sierra...Incredibly accurate and a hell of a whallop...but, no problems.
I guess there are probably heavier loads but I can't imagine anything being usable beyond that...except a heavier bullet for hunting...and you don't really need to practice with that heavy a load, I just liked it. Put a real sense of "Magnum" to the .357...I must admit....

ps...I don't advocate doing that for anyone, I just did it because I knew the gun and am an experienced reloader...If you don't have any experience, you need to start from scratch and do plenty of research and work your loads up slowly from a well published book or three...Start low and slow and be CONSISTENT...never take anything for granted and if you have any doubts, break it down and start over...NEVER SHOOT SOMEONES RELOADS...except your own...

 

[Jim March]

Got access to a chrony?

The 158 Gold Dot 357s as loaded for defense by Speer, Georgia Arms, Black Hills and Proload need to pull between 1,150 - 1,200 for peak expansion. Technically, they need 1,100 minimum but I personally like some padding on that.

See how the various versions fly in that 66. If you get one doing a steady 1,200 then bingo, that's a very good answer that a K-Frame can eat scads of without getting wonky.

 

[stans]

The concensus is that it is the 110 and 125 grain magnum loads that erode and eventually crack the forcing cone on the 19 and 66. Stick with heavier bullets and you should be fine. I do not advocate shooting unlimited amounts of full power magnums in a 19 or 66, they were not designed for that much abuse. When the 19 was introduced, it was assumed that most people, and this was the case, would practice with 38's and shoot magnums occasionally. When people and police departments started shooting carry ammo for practice, the weaknesses of the 19 and 66 surfaced. S&W answered with the L frame revolvers.

 

[Hal]

I found that with my 66 snubbie, the best load was the Cor -Bon 125 gr .38spl +P.

It shot very close to the same POI as the 125 gr .357mag Golden Sabers @ distances between 20 and 30 feet.

FWIW. My 66 2 1/2 inch didn't shoot anything other than fast stepping 125 gr loads, both .357 and .38's. I tried several slower loads and several heavier loads, and the only thing it shot were hot 125 gr loads.

The gun's long gone, but I still like the Cor Bon 125 gr. .38Spl +p for my other K frames. It comes very close (Rem lists the GS @ 1200 something and the CB is 1125 fps) to .357mag levels without the flash and recoil.

For shoot'em up range stuff.
I've found that 5.7 gr of Unique under a 158 gr lead bullet in a .357 case comes very close to the same feel as the lighter Cor Bon. POI is off though, but not by a huge margin.