Has anyone worked with this powder yet? Was at LGS and they were pimping it hard today saying it is giving super velocities on anything from 243 Win to 338 Lapua Mag. Claim 150fps increases with no pressure signs. Also say it meters great and is very temperature insensitive. Sounds to me like they read the advertising word for word.
Any input is appreciated.
Anytime someone says buy a thing that will: wash your car, Cook you dinner, give you a hummer then leave; how does your BS-O-Meter not peg?
"No pressure signs", this one bends me the most. It is very well known/understood that VERY accurately calibrated Copper Crushers can report swings on the order of 15,000 psi with the same load and test components. LUP was good until the pressures got to high. Then they went to CUP, same thing happened; so now we use strain guages or piezo electric equipment. Can anyone in the room tell me what specific alloy there cases are made with? How about what they are hardened to? Same question about primer cups?? Exactly. So if we understand that VERY carefully calibrated copper crushers don't accurately report above about 40,000 psi; then it should be not a leap of faith to understand that NOT calibrated cases, are NOT going to accurately report pressures.
Back in the WWII era when the 30-06 was in it's prime, most companies used an Olin alloy for cases. That popular alloy (IIRC C 369) was made and heat treated to 89,000 psi tensile strength. So guess where your pressures are when you can measure brass stretching...
If you don't want to buy a Pressure Trace, use a Chrony. Book loads use SAAMI min spec equipt. Your production firearm is loser than that. So if you have greater tolerances in your barrel and chamber, but match book velocities; it's because your pressure is higher.
Temp insensitivity is only that, under certain conditions. Hodgy would have you believe it is a universal property, that is a lie. As an example. Dr. Denton Bramwell has shown that Varget works where it was designed, 150gr bullet in the 308. Now it provides fine accuracy in the 223, but is FAR worse for temp stability than H335/Bl-c(2).
Specifically to the temp question about "ball type" powders. Yes, CURRENT generation technology is light years better than 1936. That year is the patent date for WC844, you know that as H335/Blc-2. The current M118LR MK-something that is the new ultra accurate 308 sniper ammo. In D.O.D. testing, the ball powder that is approved for it, has been more stable than the extruded propellant used in it.