Anyone using Superperformance in the Creedmoor?
DF
Boy-howdy!
Have burned over 16# of it in the Creedmoor, and have Pressure Trace data for it. Very stable across temps, and is very progressive in burning. What I found is that you can back off pressure by 10,000+ psi, and will only lose @50 fps because of the changing burning curve.
My first few lots were FAR slower than Hornady data (12%), the newest jug is spot on.
As to where to get it, it's all over the place.
Grafs, Midsouth, Bruno Shooters, etc.
Thanks for that info. I already have a supply of SPF to work with.
I've heard that some of the new, high performance powders, like H100V, SPF, etc., tend to be more temp sensitive than some. And, I've read that temp sensitivity can be application specific, that is, all rounds don't necessarily handle a powder exactly the same way.
So, that's good to know. I'm gonna work up SPF Creed loads with 140's. I already have a tight shooting load, Varget with 120 NBT's. SPF may be a tad slow for the lighter bullets. Your thoughts on that.
DF
So yes, any claim of temp stability being universal is from someone uniformed, or someone flat lying to sell you something. Stability is designed for an application, something similar can also show those traits. The bulk of the chatter is mostly misunderstood, and is heat-soak affecting the primer; but the powder takes the blame. Dr. Bramwell has tested and shown this several times. Varget was designed for ball ammo in the 7.62 NATO. As many know, it works wonderfully in the 5.56/223 as well. But scientifically speaking, it is a steaming pile for sensitivity in the 5.56 compared to the very old H335/Bl-c(2) powders. So don't live or die by the "Extreme" nonsense. General dynamics ball powders get tested over a much wider range of temps by the Naval warfare testing center, than Hodgdon shows. There is a very good reason why GD supplies 95+% of the propellant to the military.
Dave Emary was formerly a powder developer at GD, so it isn't a shock that Hornady has data, and not the reseller. For heaven sake, much of Hodgy data is still in inaccurate CUP!
Yes, I believe Supr may be a poor choice for light stuff. Personally I've only used 748, and it's improved variant; CFE in sub 120gr bullets.
