OK, first let me admit to having whatever small S&W expertise I do have in the realm of revolvers. That said, I have been venturing into the field of autos, in particular the 39 series. I have a couple of basic questions that will seem very elementary to the cognoscenti but not to me.

First and foremost what is the ammo prescription vs proscription For the aluminum alloy? I know that the really hot ammo intended for subguns is definitely a no-no, but what about the standard European issue NATO ammo, which is a bit hotter than US commercial stuff? I’m also wondering about a steady diet of +P from the US(?)

My second question involves rear sight assemblies. I know the slide cuts for the “lollipop” style and the ‘57 Chevy tail fin style must be specific. I’m curious though as to whether the cut for the non-adjustable sight and that for the Novak style are the same or whether each of them has a unique cut profile for a total of four?

Disclaimer; I did a quick scan of SCSW4, and while I may have just missed it, didn’t find either of these questions addressed. TIA for any info you might provide.

Froggie

Ref ammo, good ole American factory or std vel. ammo in the alloy frames.
Never bothered with +P or Alum. case Blazer.
Ref. rear sight. The factory made an adj. sight and believe Millett also did.

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Mike 2796
SoFo Bunch member

The cut is the same but the rear of the slide must be machined for the Novak sight to work.

As to your first question.
NATO 124gr 9mm ammo is rated at 1200fps and 396 ft/lbs. It is HOT ammo. I would not suggest use of a steady diet of +P ammo for any firearm. It will cause excessive wear On the gun over time. It will also depend on how much you shoot. I might fire 200 rounds a year. No worries there. I carry +P ammo in my Carry gun (Speer Gold Dot 124gr) Or HST 124gr reg vel. but practice with standard velocity ammo. JMO

As to your second question.
jsbethel has a good answer. You can always call S&W and ask them. Also ask about the hardness of the frame, steel vs aluminum.
Enjoy your 39 series auto!

Be SAFE and Shoot Often!

Aw heck .... I thought for a moment we were going to talk about cars. Cop cars, hot rods, rat rods, classics, etc.

Sorry Doug... my current interest in things automotive is pretty pedestrian. I used to build and drive Austin Healey Mk I (Frog Eye) Sprites. My last one was British Racing Green, hence my long held screen name!

Green Frog

Frog, a Bug Eye was my first car. It was a green go-kart.
It ran like a bandit. Thanks for the memory.

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Mike 2796
SoFo Bunch member

Although you can shoot NATO, +P, and even +P+ ammo in the aluminum alloy receiver S&W pistols (Illinois State Police pioneered much of this), it will accelerate wear and you should change the recoil spring somewhere around 2000 rounds. These pistols will last longer with standard pressure ammo and with that the recoil spring should last somewhere in the neighborhood of 3500-4000 rounds.


With modern defensive ammo, +P and +P+ are no longer required for reliable expansion. With modern ammo, +P usually results in faster expansion, but decreases penetration.

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VCDL, GOA, NRA

I only shoot commercial 9mm ammo in my 9mm handguns. I do not use ANY military 9mm surplus ammo in them. Years ago some unscrupulous dealers were selling war surplus 9mm ammo which was designated "For SMG use only" as conventional 9mm ammo. Many guns were damaged by this ammo. I'm sure most of it has been used up but one can never be sure about repackaged military surplus ammo. I prefer to be on the safe side.

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Bill

Am I correct in assuming that a change from the aluminum 39-2 receiver to a 639 stainless unit will increase net strength and durability? My new project I’ve been discussing is a hybrid two tone with a blue 439 upper and a stainless 639 lower. The donor gun will get here Friday or Saturday if the pony doesn’t die. I think it will give some level of improved strength and durability, but I wonder if it can be quantified(?)

Froggie

PS I still won’t be using subgun ammo in it of course, but will I have enough increased margin of strength to use the occasional Euro sourced 9mm NATO, or should I forget it altogether?

You can buy Winchester White Box with black letters 124 gr (NATO) ammo for around $9 per box. I will fire maybe 20 rounds of it along with 115gr standard velocity when I practice every 3 months or so (my secessions are always less than 50 rounds).
Shooting a $9 box of ammo vs a $40 box of Speer Gold Dot +P seems like a good idea to me and gives you the same recoil impulse. JMO

P.S. Above Winchester ammo is 1200fps. Speer Gold Dot 124gr +P
is 1220 fps just as a comparison.

Be SAFE and Shoot Often!

The stainless steel 639 receiver is heavier and more durable than the aluminum 439 receiver. Same goes for the carbon steel 539 receiver... if you can find one. I'd stay away from ammo that was specifically made for sub-machine guns, but in a steel or stainless steel receiver, NATO, +P, and +P+ are just fine. I still recommend more frequent recoil spring changes with the hotter ammo as you can get peening of the slide and receiver impact surfaces.

I think a blued 439 slide on a 639 receiver would look great.

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VCDL, GOA, NRA

In my naïveté I had come to pretty much the same conclusions. I’ll be picking up a well broken in 635 later today, then after I function test it “as is” I plan to make the slide swap this afternoon, utilizing all the best parts from the donor gun and the orphan slide to build my “Franken-Smith.” Hopefully pictures will follow.

BTW, would it be better to use OEM springs for those periodic replacements, or would Wolff springs be as good or better?

Froggie

I use S&W Factory springs in all of my 2nd and 3rd gen pistols with the exception of my 357 Sig conversions.

In those I use heavier weight Wolff recoil and hammer springs to absorb the extra shock.

357 Sig is 5000 lbs. more pressure than a 40 s&w and those extra forces must be dealt with either by spring resistance or frame battering.

I choose spring resistance, others may choose frame destruction.

John

S&W springs are excellent quality, Wolff might be a little better quality.

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VCDL, GOA, NRA

That's what I thought, too!!!!!!!!

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Come and take it!!

It's going to be interesting to see how your project turns out!

I made up a two tone hybrid, but it's the reverse... a 559 blued steel frame and a 659 stainless upper... with a comp and a curved back strap that was sold by S&W as an accessory. The grips are Uncle Mike's, which are thinner than factory wood, feels great on a double stack.

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Conrad
SWCA #1830 SWHF #222

The bushing comp and the curved backstrap are rare and hard to find items for the 1st and 2nd gen S&W pistols.

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VCDL, GOA, NRA

As a Life Member of SNM I shoot only steel frames. Bullseye shooters never asked for lighter frames and many rounds did they fire ?
My understanding is the 9MM has always been a "hot" round so a heavier gun and springs will extend shooting life. And I have found that with careful reloading the 9MM can be very accurate.

Two reasons for aluminum allow receivers. First, they are lighter weight and easier for a soldier or law enforcement officer to carry every day, all day long. Second, aluminum is easier to machine than steel or stainless steel. They are not more durable than steel or stainless and do not lend themselves to rail tightening that is done to bullseye competition pistols.

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VCDL, GOA, NRA

Well, it looks like I’m headed in the right direction. I’ve got Dad’s old 39-2 set up the way he and I envisioned it, and when I need a light and flexible semi-auto 9mm to carry around, I’ve got it.

Meanwhile, for a rough-and-ready use and more extended shooting, the plan to build up a 639 with its durable stainless steel receiver will be my go-to gun. It will have the same control features as for now, but will also be able to serve as a test bed for future improvements.

All of this is new territory for a guy who has been carrying revolvers for a long time, but it has been an interesting journey.

Froggie