S&W Model 37 Date of Manufacture & +P Compatability

I don't think it is rated +P.

Question: What exactly do you intend to accomplish by using +P ammo in this J-Frame?

For some reason, serial number information found in the Standard Catalog of Smith & Wesson, isn't very detailed for the numbered series J frames. However, there is enough information there to make an fairly educated "guess". We know that the "J" letter series began in 1969, so we know your gun is older than that. It lists serial # 295000 as 1962, so we know your gun is older than that. It lists serial # 125000 as 1957, so we know your gun is newer than that. And that is about as close as I can come. Given the numbers listed and your serial number, it would be a good guess that yours came out in the 1961-1962 time frame.

As for the +P ammo, there is no reason to suspect that some occasional shooting of it will damage your revolver. You would certainly not want to shoot a steady diet of it. Doing so would most likely accelerate wear, and too much of it could crack the frame. But that is the same concern for one purchased new today. Moderation is the key. I carry +P in my 642. I shoot +P in it on an infrequent basis. Shoot enough of it to become comfortable in knowing what it feels like and where it shoots.

Having been on the internet firearms forums since before they were called "websites" or "forums," your question is interesting because it used to come up regularly. I can tell you that back in the early 2000s, on TFL and the S&W Forum, there was frequent discussion of this exact topic. Consensus generally was you'd meteorically speed up wear on an Airweight with a steady diet of Plus P and risk catastrophic failure. There were anecdotal reports in the early days of Model 37 frame cracking with limited use of Plus P (on the other hand, older 37s have failed with standard pressure ammo). Then there was a long-time member of the S&W Forum who shot thousands of rounds of the higher pressure loads through a Model 12 (the K-frame Airweight) with no apparent effect. My thinking though, is that there's absolutely no reason to go the Plus P route in an old Airweight. First, it's brutal to fire. Second, there are alternatives that allow you to shoot what you carry, that have also been tested and do quite well in the standard testing.

Maybe take a look at some of Buffalo Bore's hard-cast wadcutters in the heavier weights (150 grain or more): https://www.midwayusa.com/product/1...38-special-150-grain-lead-wadcutter-box-of-20. It's generally known that out of a two inch barrel, .38 SPL doesn't acquire enough velocity (even Plus P) to always reliably expand JHPs. A hard-cast bullet is old school technology, but it's proven. I like this one myself for my older revolvers: https://www.ammoland.com/2013/12/38-special-wont-shoot-plus-p-buffalo-bore/#axzz5ofvoZK59

Back when I bought one of those 37-2DAO snubs that were released on the market after a foreign contract was canceled, I was curious if they were rated for +P. I was seeing a lot of contradictory info being posted online among gun forums.

Being a S&W armorer, I decided to call the factory and ask them about it. The first answer I got was a hesitant "yes" about using +P from the customer service call taker, after they'd asked someone else. However, then I pressed and asked for some details, explaining I'd read that some of the 37-2DAO's had barrels with +P markings, and some didn't. Why the different barrels?

I was told they were going to put me on hold and call over to Revolver Production and ask about it for me. When they came back on the line I was told that Production had told them that none of the older style "short frame" Airweight 37's had been made with the use of +P ammo in mind. Only the newer model Airweights (like the 637's, etc) made on the longer frames (think longer cylinder frame windows and cylinders) had been designed and intended to be used with +P ammo.

Apparently, it seemed that in order to make that particular overseas production run of the 37-2DAO's they'd used a number of 442 barrels that were marked +P, and some regular M37 barrels that weren't marked for +P. The inference seemed to be that the offshore police agency would never use +P, anyway, but only standard pressure ammo, so it hadn't been considered a problem to use both types of carbon steel Airweight barrels to complete the order. I asked them what would happen if some of the American buyers who had bought the guns with the +P marked barrels used +P ammo and experienced damage to the frame (like a crack in the frame under the rear of the barrel)? The response was that they'd have to handle that sort of problem under their warranty. How could they blame the customer if they'd used +P in one of the guns made with a barrel clearly marked for +P?

The upshot of it was that I decided to never use +P ammo in my older style 37-2DAO. I only use standard pressure loads in that neat little DAO Airweight. I save the +P ammo for my pair of 642-1's that are clearly marked as approved for a diet of +P, and in my steel J's and M&P 340's.

Just my experience and thoughts.

Your revolver was made before there was such a thing as plus P ammunition. In the early 70s SAAMI changed the specs for a few handgun calibers. They actually lowered the allowed pressure of the cartridge and at the same time they came up with the plus P specifications. Plus P pressures were basically the same as what the previous max allowed pressure had been before they lowered it.
That being said, common sense says a more powerful load will lead to more wear & tear on any gun

IMO the only ammo you need for an alloy J frame is factory target wad cutters or equivalent. Works great as a SD load.

JMO

When I carry my Model 38, I load it with Remington 158gn +P swchp. I don’t shoot it much, though. Frame cracking under the barrel is very real with the old Airweights.

My son carries a well loved model 37 loaded with the Winchester 130gr Train and Defend JHP. Here is some gel testing done by Lucky Gunner on that ammo.

FWIW, after I bought my 37-2DAO back about '05 (I think it was?), I looked around and started using standard pressure 110gr JHP loads in it. I settled on the Federal Hydra-Shok and Winchester STHP. Both shot very well (accurately) in my Airweight, in my hands. Maybe the JHP's might even deform or expand. If so, that was an added benefit to me.

A little later I picked up some of the standard pressure American Gunner 125gr XTP's to add some slightly heavier bullet weight, although I wasn't expecting much in the way of bullet upset/expansion out of the short barrels.

I eventually decided to try some of the Hornady 110gr standard pressure FTX/Critical Defense. I was pleasantly surprised by it producing less "snap" than both the Fed & W-W standard pressure 110gr loads, and it demonstrated itself to be a tack-driver out of my little Airweight, and then one of my M&P 340's. I decided to stock up on a few boxes of it and have it available as an alternate load, even in my +P capable J's.

Granted, I still think it's handy to have the heavier +P loads available in 125gr, 130gr & 135gr for my +P capable J's, as sometimes bullet weight might matter a little, but the ease and controllability of the 110gr FTX loads makes rapid shot strings about as easy as anyone might ask. It made me think I might as well be shooting the low powered 130gr ball or 148gr target wadcutters.

We have some nice ammo options being developed for the little snub revolvers nowadays.

The early Air Wt revolvers didn't do well with some of the early Hi velocity ammo like Super Vel. I remember reading in the gun magazines about police officers reporting their air wt's being damaged to the point of ruin with only a box or two using the "police ammo" of that time. It was mostly from the ammo stretching the frame, not KB's.

I own a modern 637 air weight rated for +P as my EDC and have no worry about shooting such ammo in my gun. I load it with factory +P, currently Federal 130gr HST, Remington 125gr Golden Sabers, or Speer SB 135gr Gold Dots. Each of these loads do well in the YouTube gel and denim expansion and penetration tests from snubs. The HST's are chambered for initial carry but they're a bit difficult to load quickly from the Safariland speed loaders so the longer easier loading Golden Sabers or Gold Dots fill the role as spare ammo.

If you own a 60's - 70's J frame not +P rated I would recommend to carry +P ammo only if you wish but shoot It minimally. If you want to keep your gun in good operating condition use standard velocity ammo for practice and even consider using it for defense. Stay away from the extra power custom High velocity +P ammo from the likes of Buffalo Bore or Underwood that are more likely to damage an older handgun with early alloy frame .