During the Obama years we all began to move out of our comfort zone & use different propellants ......... using what was available.
My son calls me. He's in a distant city @ a sporting goods store & says he could get 8 lbs. of WST & wanted to know if I could use it. I did some quick research & told him to buy.
WST is now my .38 Spec. & .45 ACP powder (it'll also work well in .44 spec. , but I use Red Dot there).
It burns clean, meters perfectly, accurate & it's bulky. My 550 is not equipped with any aftermarket light but with a common goose neck lamp I can see if I have a double charge (haven't had one yet).
One image shows a 4.7 gr. charge (200 gr. #068.......5.1 is max.). The other image shows a double charge.
I use 4.2 gr. with the #452374 (4.3 is max).
I like HP38 & have plenty on hand, but use more WST now.