Unique powder, load data from Frankford Arsenal manual pub. 1999 (357 Magnum)

[schuetzen]

I have a few sources of loading manuals and although there were no exact recipes for the bullet:powder (Rainier 125 gr JHP bullet - Unique powder) that I am looking for, there are a few other examples to compare, like jacketed bullets and lead bullets.

Yesterday, I found a Frankford Arsenal 357 Mag loading manual published in 1999.  It has recipes for Rainier plated bullets with Unique (data below).

Rainier bullets are plated, not jacketed.  From Rainier website... "We, at Rainier Ballistics, recommend using lead bullet load data when loading our bullets. There is no need for adjustment when using lead bullet load data. Our bullets are jacketed using an electroplating process and are softer than traditionally jacketed bullets; hence the recommendation to use lead bullet load data. If you only have access to traditionally jacketed load data, we recommend reducing maximum charge by 10%. A roll or taper crimp may be used with our bullets; do not over crimp."

However, even taking Rainier Ballistics recommendation of reducing other jacketed bullet recipes by 10%, some recipe's *starting* charges are at the upper end of the Frankford Arsenal recipe charges below.

From Frankford Arsenal 357 Mag loading manual:

Rainier 125 gr JHP (Rainier bullets are copper plated, not jacketed)
Alliance Unique Powder
Maximum charge (using extreme caution) 6.9 gr 35,000 PSI
Maximum recommended charge 6.6 gr 32,800 PSI
Starting charge 5.5 gr 24,800 PSI

Does anyone know if there has been any significant changes in Alliance Unique powder since 1999?

Does this load data from Frankford Arsenal look reasonable?

[JustaShooter]

Alliant changed Unique's formulation in 2001 to a new, cleaner-burning formula.  They claim the same burning rate, and reloading manuals that I've checked show essentially the same charge for a given load before and after the change, but change is change...

Just a Shooter

[Dand]

See if you can find a recent Lyman load manual and see what they recommend for a 120-150 gr lead and Unique.  Keep in mind, the main problem with shooting plated bullets with jacketed charges is that the plating may come off the bullet and accuracy will be poor - and may crud up your bore. I don't think you have to worry about blowing things up or anything. And, 1999 isn't that long ago and should be reasonably acceptable.

Given that Unique is a very popular powder, I'd expect Alliant would have made a lot of effort for any new formulation to perform closely to the original.  The one big variance I know about was when Hodgdon ran out of WW2 surplus 4831 and had new stuff made that turned out to be quicker than the old; that was back in the 1980's I think and there were lots of warnings posted.

I checked Berry's who also make plated bullets"
 "Plated bullets occupy a position between cast bullets and jacketed bullets. They are soft lead, but have a hard outer shell on them. When loading plated bullets we have found best results using low- to mid-range jacketed data in the load manual. You must use data for a bullet that has the same weight and profile as the one you are loading. Do not exceed mid-range loads. Do not use magnum loads."

You might try calling or emailing Rainier for suggestions. I would expect the low end load recommended by Frankford would be a good starting point.

Oh, and don't scrimp on load manuals - more is better.