+P in a M642-1 is ok, but not in a M10-5 4” barrel

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fotojake

New member
How come? That K-framed 10-5 (tapered barrel) certainly seems more stout than that lightweight 642-1.

S&W replied to an email and said that +P wasn’t certified in the 10-5...

“Lastly, Smith and Wesson firearms did not start to be rated for Plus P until 1997. Any firearm made before that is not rated for use of Plus P ammunition.”

Any theories?
 
The metal has to be sufficiently hardened to handle the pressure. It's the cylinder that has to take the pressure, since that is where the pressure will peak, not the barrel. Pressure tends to peak after only limited bullet travel.

Perhaps - they aren't confident that the metallurgy of the pre-1997 is up to a diet of extra pressure loads. either way, it's their advice.
 
Well, they're right. The 10-5 wasn't rated for P+. Of course there was no such thing as P+ back in it's day. I personally wouldn't hesitate to fire them from time to time in any S&W or Colt made since World War II. The gun is not going to blow up in your hand. In THEORY, if you shoot enough of them, you might loosen the gun up to the point you'd have to have some maintenance done. That would probably take about a truck-load of ammo, but you could probably do it.

I own three Model 10's. A 10-2, and a couple of -5's. I don't shoot P+ in them because I don't see much sense in shooting expensive ammo to punch a hole in a piece of paper. If I was ever going to use one of them for self-defense, yea, I might shoot a few just to check the point of impact and recoil, but in my experience neither of those change enough to really worry about.

YMMV
 
so same material and process to make a model 19 cylinder was used for the model 10 cylinder (except for size) and the model 10 "can't" shoot" .38 +p? this story is only because (as mentioned above) the +p designation wasn't used back then....Hi-Vel made a 110 gr. .38 special load for the border patrol way back yon...... it was essentially a light .357 load. just throwing that out there....
 
so same material and process to make a model 19 cylinder was used for the model 10 cylinder (except for size) and the model 10 "can't" shoot" .38 +p?
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not exactly.

First off, there is a difference between the model 19 and model 10 cylinders, and that is the heat treatment S&W applies. They aren't the same. Magnum cylinders get a different heat treatment than standard calibers.

Does this make a difference? I'd say at .38+p pressures, no, but at magnum pressures, yes.

second, S&W is not saying you cannot use +p in the model 10. They are saying they don't "rate" or "certify" the model 10 for +p ammo.

The difference is subtle, but important.

What is missing is the explanation WHY S&W doesn't rate that gun for +p.
It has nothing to do with the gun's strength, it has to do with legal liability.

S&W never tested the model 10 with +p ammo. And since they never did their own tests, they will not rate/certify the gun for ammo they didn't test in it, on the record.

Off the record, guys who work there will tell you the gun is plenty strong enough, and you can look at NY, Chicago, and LA PDs using those guns with +p ammo for decades without issues due to +p pressures.

I personally wouldn't hesitate to fire them from time to time in any S&W or Colt made since World War II. The gun is not going to blow up in your hand. In THEORY, if you shoot enough of them, you might loosen the gun up to the point you'd have to have some maintenance done. That would probably take about a truck-load of ammo, but you could probably do it.
Click to expand...

I pretty much agree with this, but it may not take a whole truckload of ammo, depending on the specific gun. For example, I have a Colt Agent .38 (alloy frame Detective Special). Back when Colt was making them, they DID rate the gun for +p ammo.

HOWEVER, they asked that at 1,000 rounds you return the gun to Colt for inspection, and possible repair. And every thousand rounds there after, as well.

Very few people would ever hit that round count from that kind of gun, but if you did, Colt wanted to check the gun, just to be sure everything was ok.

Personally, I put 1,000 rounds far below a "truckload". :D
 
I pretty much agree with this, but it may not take a whole truckload of ammo, depending on the specific gun. For example, I have a Colt Agent .38 (alloy frame Detective Special). Back when Colt was making them, they DID rate the gun for +p ammo.
Click to expand...

Well, yea, but then a Colt Agent 38, with an alloy frame, isn't exactly a Model 10 eiither. ;) :D
 
If anyone remembers the gun writer named Jan Libourel who wrote for Guns & Ammo for many years he stated S&W told him they heat treat the 38 special and 44 special cylinders the same way they heat treat the 357 and 44 mag cylinders.

So I think you will be safe shooting the weaker +P ammo in your gun.
 
The old s&w rule used to be, if it had a model number, it was safe with +P.
That said, I've shot a couple hundred rounds of +P in my pre-Model 10...it eats them like candy.
 
Here's my well used 1942 M&P pictured with some of the 500 rounds of Remington +P and 600 rounds of my own +P+ that I put through it in a two week period to see if anything would happen. Came as no surprise at all that nothing did.


standard.jpg
 
Regarding Smith's response to the OP about use of plus P .38s, it's
true if Smith says so that they didn't mark the barrels +P until
1997.

I think that came about because so many questions were being asked
about the J-frame Smiths. The response the OP got from Smith was
a blanket response but I really doubt it actually refers in practice to
the K-frame models.

Someone at the home office took the conservative route and pointed
to the Plus P markings for a J-frame. I doubt the Smith responder
had any more technical knowledge of the company's metallurgical
history than Mother Teresa. Well, maybe a little more than that
sainted lady. But not much.

I don't believe any K-frames were ever so marked.

And history and practice indicates the K-frames in steel
are perfectly adequate to handle the so-called Plus Ps.
 
Any theories?
Click to expand...

No, just some facts.
1997 is when S&W began using the new “J Magnum” frame on all their J frames. Hence the new 357 magnum J frames and the 38 Special guns being rated for +P.

For K frames guns, S&W has long stated that if they are model marked (about 1957 forward) they are safe with +P.

Jim
 
I am looking at an old Smith and Wesson Revolver owner’s manual with “Revised 6/93” printing date. It contains a revolver ammunition chart in which it clearly states that a Model 10 (no dash number specified) is marked as rated for +P 38 Special ammunition. It has a further warning that +P ammunition should not be used in revolvers produced prior to 1958.

Horse’s mouth.

A number of J-frames with steel frames were rated for +P prior to 1997, but not all for some reason. None of the aluminum framed revolvers were so rated until the introduction of the J-magnum frame in 1997. Some model 640’s were marked +P+ but mine is not.
 
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