Why are 125/130 grain .38+p so slow?

[willie]

I hesitate to say that S&W's metallurgical improvement timeline is a secret. When I began buying their revolvers in 1970, I remember that these discussions were underway then. The consensus was that then they differed in caliber and frame size but not metallurgy. I no longer can provide citations or sources but had many conversations with the product service manager during the 70s. The Smith forum should be able to shed light. I can do some digging and find a phone number for the man who had the last warranty repair shop in Texas. He's still in the general gunsmith business. I would pm the info so one of you could call him.

[olstyn]

Was it that high in 1902?

My apologies; I did some googling but could not find a reference to the original pressure spec. SAAMI and CIP both came about later on, (in 1926 and 1914, respectively), so...? Supposedly Georg Luger's original load was a 124 gr bullet at somewhere in the neighborhood of 1070 FPS, but that doesn't really tell you anything conclusive about pressure, since you can make that velocity with both small charges of fast powder (high pressure, but brief duration) or larger charges of slower powder (lower pressure, longer duration).

[Alpha Sierra]

I wonder if S&W ever implemented some tests, or did some calculations regarding frame/cylinder/forcing cone strength improvements with improved metallurgy, or if they simply said "lets use a different steel, or heat treat it differently".

Good Lord, of course testing and validation is done before placing any engineering change into production. The type and thoroughness of the testing depends on many factors, among which are the risks associated with field failures.

No one can seriously believe that engineering changes are chosen without any sort of testing and validation.

[Navin Johnson]

When 158 grain bullets have no problem going 1000-1250fps?

I'd think a 125/130 should easily be able to do the same.

And then what would happen?

[Jim Watson]

The serial number at which S&W started heat treating M&P cylinders is known. Post WW I is as close as I can get from memory.

A long time popular .38 Special load is a 158 gr lead bullet and 3.5 gr Bullseye. (Introduced in its present form ca 1904, original type in 1898.).
Lyman finds this at or near maximum 16000 CUP, depending on which of their 150-160 gr molds is used.
Phil Sharpe showed that load at 15000 crusher psi in 1948.

[Duelist]

The serial number at which S&W started heat treating M&P cylinders is known. Post WW I is as close as I can get from memory.

A long time popular .38 Special load is a 158 gr lead bullet and 3.5 gr Bullseye. (Introduced in its present form ca 1904, original type in 1898.).
Lyman finds this at or near maximum 16000 CUP, depending on which of their 150-160 gr molds is used.
Phil Sharpe showed that load at 15000 crusher psi in 1948.

Definitely. One of my favorites, too.

[TiroFijo]

Good Lord, of course testing and validation is done before placing any engineering change into production. The type and thoroughness of the testing depends on many factors, among which are the risks associated with field failures.

No one can seriously believe that engineering changes are chosen without any sort of testing and validation.

Are you sure? I XX steel gets replaced by stronger YY steel, all else equal, I seriously doubt they bother to test an existing design that had proved to be strong enough with the lesser material.

[Alpha Sierra]

Are you sure? I XX steel gets replaced by stronger YY steel, all else equal, I seriously doubt they bother to test an existing design that had proved to be strong enough with the lesser material.

I am certain. When talking about structural integrity things aren't as simplistic as you make them sound.

I've been an engineer for over 30 years and a manufacturing professional for 25.

[Borderland]

When 158 grain bullets have no problem going 1000-1250fps?

I'd think a 125/130 should easily be able to do the same.

Where are you seeing 158's in a plus P load with a faster velocity than a 125?

With pressures being about the same the 125 will always be faster.

Here are some loads using Bullseye from Alliant.

125 JSP, 4.8, 1090, 17200
158 LSWC, 3.8, 945, 16800

Heavier bullets will always produce more pressure with the same powder charge. That's why Hornady 38 spl. Critical Defense ammo ( not plus P) uses a 110 gr bullet. The lighter bullet uses the increased velocity to expand.

[Alpha Sierra]

Where are you seeing 158's in a plus P load with a faster velocity than a 125?

Compared to the mainstream manufacturers' 125 grain +P loadings, these all qualify
https://www.buffalobore.com/index.ph...t_detail&p=108

https://www.buffalobore.com/index.ph...t_detail&p=288

https://www.underwoodammo.com/collec...18785707491385

https://www.underwoodammo.com/collec...18785707524153