.357mag, then & now

[2zulu1]

I was reading an article about 357mag/2400 written by Paco Kelly and went back over some of my own reload data, mostly looking at 125gr/158gr weights. Most of my loads use AA #9 or H110, I've tried N110 but was getting difficult ejection from a seven shot M686.

Back from 2006 notes I had chronograph data for 125gr Sierras loaded with 2400 powder, 2" groups @25yds with both a 6" M686 and 6" Mk III Trooper. While the 2400 load weights were/are well w/i Sierra's published data, Sierra's load weight range exceeded the weight that Paco Kelly had written about at leverguns.com.

Let's go back in time to 1978 and Sierra #2, MkIII Trooper/6";
2400 - 14.8grs-19.0grs
Sierra fifth edition 2003; 2400 - 16.2grs-19.0grs (increased starting weight)

Speer #10, 1979, Ruger Security Six/6";
2400 - 17.5grs-19.5grs; pressure slightly under 46,000 cup

Speer #14 2007, M19/6"
2400 - 16.5grs-17.5grs do not use magnum primers, loads under 35,000psi.

My personal 2400 data used a Blackhawk/7.5", MkIII Trooper/6" and M686P/6", but I'll only list the 686 MVs, it's a fast barrel. Win brass, WSPM, 1.585", 125gr Sierra JHP:

18.0 - 1458fps, ES 85fps, 2.0"@25yds
18.3 - 1602fps, ES 59fps, SD 21fps
18.7 - 1647fps, ES 58fps, SD 23fps

For whatever reasons, Sierra has kept their 2400 data the same for at least three decades and Speer chose to drop their operating pressures.

Of interest, VihtaVuori #4 2006 load data does not exceed 43,500psi for those who like to use this line of quality powders.

While Speer and Hornady are loading down the mag, both Sierra and VihtaVuori are as potent as ever, just be sure to safely work up loads in your 357mags according to protocol.

 

[ArchAngelCD]

In your above post you quoted both CUP and PSI pressures. Remember, both are different and can not be converted. From what I've read 35,000 PSI can be as high as over 43,500 CUP.

 

[Steve C]

Speer has changed from a conventional copper jacketed bullet to their Gold Dot series which is a copper plated bullet, Hornady has gone to their XTP bullets so this may account for the changes in their load data. Sierra on the other hand has maintained the same type of bullet they've sold for the last 40 years.

The data one gets from any of the reloading sources is only described by the publishers as being below SAAMI maximum pressure, how much below is anyone's guess. The bullet manufacturers don't just push their loads to max pressure but publish loads that produce the best accuracy in their tests and top the load data out where that accuracy dissapears or pressures become erratic.

 

[336A]

I know that this is not about the .357, but it is about 2400. The Sierra 5th edition manual and Speer #14 share the same max load for the .41 magnum with their repective 210gr bullets which is 19gr. Hornady's 210gr XTP-HP is shorter in length than either of the other two bullets and goes up 20gr of 2400.

Now what is funny is Lyman has decreased their top loads in the .41 mag and 2400. The reason I say it's funny is a cast lead bullet will go down a barrel with less friction and pressure vs a jacketed bullet The only thing that I can think of is that Lyman uses a universal receiver instead of actual firearm, so maybe the pressures are higher.

When comparing a commercial cast 210gr SWC next to a Sierra JHC you can see the the cast bullet will protrude slightly less into the case. So I don't understand how a JHP can go up to 19gr while Lyman only goes up to 17.1

 

[GP100man]

I feel the problem is the industry picks certain calibers to retest with better equipment & we as handloaders have to stay alert as to what we interpet & load .

Each firearm is different as you & I ,what may be perfectly safe in 1 may give sticky cases or give hard bolt lift in the next .

 

[Ford Prefect]

Hence, this is exactly why we are seeing "ruger only" loads apearing as if it's a wildcat. We all know a 6" GP100 is in a different league than an aluminum snuby, but SAMMI seems intent on making standards suited to the minimum.

 

[2zulu1]

Deleted partial post, see below

 

[2zulu1]

I understand the frustrations of trying to correlate ANSI/CUP and ANSI/PSI for the calibers they've published their data for.

With 2400 powder, Lyman #47 (1992) lists 17.7grs/125 as a factory duplicate load, 40,600 CUP (p391).

Speer 14, states 17.5grs does not exceed 35,000 psi, so it appears that 17.5grs/2400 would be closer to 40K CUP than 43K CUP.

Getting a grip on Speer's 19.5gr/46K CUP as it relates to PSI is in the "I do not know" category for me. What we do know is that Speer dropped from a 19.5gr max to a 17.5gr max load in order to get under 35K PSI, Sierra has not changed their max load data.

Regarding bullet construction changes during the past two decades, here's some chrono data I have from nearly six years ago;

W296 - 20.7grs, Win, WSPM, 1.582"
125gr JHP Sierra - 1635fps, ES 49fps, SD 18fps
125gr GOLD Dot - 1626fps, ES 60fps, SD 23fps

For all practical purposes, both designs share the same MV so it's doubtful the two designs create any meaningful differences in chamber pressures.

Again what I don't know and is speculation on my part, is that the 19.5gr/2400/46K CUP could very well be upper 40K PSI, like the original 357 mag pressures.

Thoughts?