It wasn't until the Barackolypse that I finally decided to try Promo. "Save some money" I thought... and it certainly does seem like it when you are in the checkout line with an 8 lb'er. Fact is that you -do- save money with this stuff but it's still the cheapest part of the entire loaded round in handgun ammo.
Just the same, I had an 8lb'er of Promo so I was going to make use of it. And I tried it a bit in 9mm and a bit in .38 and I set to work with it in .45.
In 9mm, I barely did much... simply, I just love the 9mm load I have made for years, using Hodgdon Universal. Promo certainly seemed to work, much like it is showing you in your testing.
In .38... well, I basically HATED it. To be fair, I'm sure I could have done better had I tried harder... but I passed on it quickly.
In .45, under 230gr plated RN, it worked VERY well! It worked so well that I just cooked and cooked and cooked with it, it became THE hardball load at my bench. And two days ago after a session of 550rds of .45, I went to re-fill my one pound can and found that my 8lb'er was FINALLY empty.
I have less than a pound of Promo left. Quick calculation tells me that I have actually rolled over 10,000 rounds of .45 Hardball with Promo!
Worked well for me but honestly, I am totally addicted to Bullseye in other stuff and I buy a lot of Bullseye and Bullseye also works awesome in .45 and Promo is just not great for me anywhere EXCEPT .45, and that means after loading 11,500 rounds of .45 with Promo, my little affair with it will be over and done with, page turned. End of an era. Fond memories and no plans to buy any more of it going forward.
For other prospective users, do beware -- it isn't the easiest metering powder ever.
Now... did I save money by using Promo? Well of course I did, but consider that all else being equal (meaning shopping from the same place and in the same era, not comparing prices from 2008 from different stores, etc) Promo will save you maybe $35-$60 for that 8-lb jug.
If I did the math correctly (I did it quickly...) then using Promo saved me roughly 3.83 cents per 50-rd box.
I like to swap brass... and I'm looking for .32 H&R Mag, .327 Fed Mag, .380 Auto and 10mm. If you have some and would like to swap for something else, send me a note!