I don't use extruded flake propellants for defense loads, so I can't answer the Universal question. Most shooters that use it get very good accuracy and at least factory ammo level velocity is achievable. One requirement I have for defense loads is minimum flash. The powder I used a lot until the last few years was V-V 3N37. Low flash and very high velocity potential for pressure generated. Now they have 3N38 that is a little more capable with bullets of 165 grs. and heavier. The continual price increases of Vihta Vouri powders took me on a quest to find suitable replacement. In .40 S&W, I have had very good luck with 2 powders from Ramshot: Silhouette and True Blue. Silhouette is treated to keep flash to a minimum and has an energy potential very similar to 3N37. I suspect that Primex set out to make a competitive product for Winchester who formerly sold it as WAP and loaded in their first commercial loads.
True Blue is excellent in the accuracy dept, and outstanding with cast bullet loads. Flash is low enough. Silhouette is capable of higher performance with even less flash. Both meter very well, but at 935 grams/liter, True Blue flows like hourglass sand. Silhouette is 800 grams/liter, but that's still denser than extruded flake propellants. In my opinion, these are the best powders available for .40 S&W, and both are a bit slower in burn rate than Universal. both are similar to HS-6 and N340 in burn rate. I don't like anything faster than Unique/Universal because of the naturally fast pressure peak common to the .40 S&W. Not to say that you can't use a number of different powders for plinking/target loads, but for defense type loads where you want all of the velocity possible; enough to get the bullet into what seems to be the ideal level for performance at 500 - 550 Ft/Lbs of kinetic energy, I like slightly slower burners that have good energy potential. I wouldn't choose W231 for this.
You'll probably need another source for data, and if you don't have a Sierra manual, talk to someone who has the latest edition, or call Sierra directly for data at 800 223-8799. Naturally, they'd probably prefer that you were using Sierra bullets, but I bet they'll help. Silhouette is capable of very good performance, but you'll need data that reinforces that and Sierra is the best source I've found. Several manuals do not yet have data for Ramshot powders. Also, Winchester data for for WAP is interchangeable. In fact, Ramshot data for Silhouette is the same data Winchester generated previously. Try Hornady as well. I know I'm not helping much with exact load data because my bullet weight preference runs 150 - 165 grains. I use the Nosler 150 and the 165 gr. Golden Saber.
If someone here has the latest Sierra Manual, maybe they'll jump in and list the charges for these two powders. Either is great, but for defense, I'd recommend the original .40 S&W powder. WAP which is now Ramshot Silhouette!
