New vs Old Data

C

cdoc42

New member
Every now and then I'll look up data on new powders to compare to what I've been using.

I have a Ruger GP 100 in .38 Special/,357 Mag that I have been using since the mid-80's.

Hodgdon's data for CFE Pistol for .38 Special, 125gr JHP (although thei data is for XTP; I'm using a Remington JHP) shows 5.4gr (995fps) - 6.3gr (1133 fps),

I have a new Lyman edition so I looked up the recipe I've been using and it lists Unique 4.0gr (498 fps) to 6.0gr (895 fps). WHAT!? My boxes of loads are labeled Unique 6.5gr at about 1050 fps. Where did I get that recipe? Well, I looked in Speer, Hodgdon, Hornady and again in Lyman to no avail. I've been shooting this since the mid-80's without a problem. Finally I found an old Hornady Second Edition manual (first ed.= 1973) on the shelf, an there it was:

Unique 6.1gr for 950 fps to 7.3gr at 1100 fps.

Hodgdon's recent manual lists Unique as simply 5.3gr for 1015 fps.

Now I know they're using different length barrels, but should I be adjusting my loads since the "new" powder might be producing more pressure even though I'm not having any problems?
 
You should revisit what is happening, for sure. All that old data was worked up in production firearms and never properly pressure-tested. It can be too hot for a gun that is tighter than the test gun was or when using brass that is softer or thinner. I also have a copy of that old Hornady #2 and found at least one recipe in it for 2400 in 44 Special that had a starting load that was already at maximum for my light Charter Bulldog. That happened because they worked the load up in something a little heavier.

The Lyman data is pressure-tested, unlike the Hornady, so I would be more inclined to believe it.

These days, what with liability lawsuits and all that, the databook authors actually test pressure for most maximum loads. In addition, some powders, like Unique, have been reformulated since then. They try to keep it close to the original, but it won't be exact.
 
I always prefer to use the powder manufacturer's data. You can find Hercules annual pamphlets as far back as 1987, and some older manuals too, here:
http://www.castpics.net/LoadData/Freebies/default.html
I looked at Alliant 1996 and they do not support Hornady's higher load you quote. I would say it looks like a typo or something. Alliant's 357 loads are even higher, so I am not shocked your loads performed OK in a 357 revolver.
I always feel more comfortable checking multiple sources for load data. Hercules/Alliant data has been fairly stable of the past 25 or so years. They may no longer publish, for example, Red Dot and Green Dot Revolver loads on their website, but will email them to you if you ask for them.
Edit: In 1987 they published 6.5 gr Unique for 38 Spl 125 JSP, but shaved it to 5.6 for +P a few years later.
 
Last edited:
My boxes of loads are labeled Unique 6.5gr at about 1050 fps.
Click to expand...

CAUTION: The following post includes loading data beyond or not covered by currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.

Your 38 Special loads are a bit hot. My go-to 125gn JHP +P loading using Unique is 6.4 grains - and it's one of the few loadings of mine that exceed published max (Speer #15 has max at 6.0). It chrono's at 1063 f/s through my 4" Smith M67 K-frame. It's a peppy round; but far short of being magnum-ish. I have complete confidence that the gun is more than strong enough to handle it. On a typical range trip, I shoot maybe three cylinders full; so it doesn't get a steady diet of these.

I shared my load data to show that 6.5 is heavy for 38 Spl, but not likely dangerous in a 357 gun. That said: I agree with Unclenick. It may be time to do a new work up to see if a little less charge weight will suit your purpose. Sounds like you've been loading as long as me; so I'm not dispensing advice. Just giving some perspective.
 
Nick C_S, never apologize for giving advice or perspective; one is never too old or experienced to learn something. Thanks to you, Unclenick and Marco.

Earlier this evening I loaded 20 rounds with CFE Pistol using current information. As soon as this stupid snow melts and the temperature moderates I'll try it out.
 
Another thing to consider is the firearm you're using . You're loading hot 38spl loads and using a 357 mag firearm . I'd think you could go much hotter and not have an issue until you shoot them out of a little 38spl only firearm .

I'm no expert with the 38/357 , I mean like at all . How ever it confused me a bit when I kept seeing 38 loads stopping at 5gr of powder x and 357 loads starting at 7gr of that same powder x . That sure seems to say if you're using a 357 firearm the 38spl max load is really not max . I know you should never go over 38spl max charge when using 38spl brass because it can be fired in a gun incapable of handling the pressure , but you can . I don't do that , my point there is your specific issue should be moot because the gun can handle what you are doing . I always use 357mag brass even when loading at 38spl pressures . This allows me for the most part to load from the 38spl minimum to 357mag max . I don't remember the load off hand but I have one that's right in the middle of the max 38 and min 357 load data .
 
You must log in or register to reply here.
Back
Top