pitted bore wrote:Stealthshooter wrote:I was just wondering if anyone has tried Alliant 300-MP yet for the 450? ...
I may have been the first person to try 300-MP in the 450B.
I didn't report the results from more than two-and-a-half years ago, because they were not encouraging. However, it's perhaps time to release them, so I wrote a description that turned out to be so long that it needs it's own thread.
(Link to thread: Some Early Trials of Alliant 300-MP Powder in the 450B.)
Your results with the lighter bullets and to a lesser degree with CCI 41 primers don't surprise me given the burn rate of 300-MP, which falls slower than W296, but faster than 1680. In my 20" 450b, I had lackluster results with 1680 and the 300 grainers. While faster powders like Lil Gun and W296 worked with them, the recoil impulse felt like they were popping fast and burning out long before the bullet left the barrel. I am hoping that 300-MP helps fill the gap between those powders. Also, I'm hoping that the lower end of the sweet zone for 300-MP drops down to include 275gr and possible 250gr bullets, to take advantage of the entire 20" of barrel and yield good velocities at lower pressures and acceptable accuracy. To that end, I wish I were testing with XTP Mag 300s as in the case of my rifle, I got better accuracy from the XTP Mag family than from their Speer counterparts. For me, accuracy falls a little higher up the importance ladder than milking every last fps out of the recipe.
The purpose of my first rage outing of the season will be to characterize 300-MP with the 300gr bullets I have. Since it is not supported in my version of QL, I'm also taking long my 7.62x40 upper and a ladder test progression to try and characterize it in that caliber, which loves Lil Gun, W296 and according to other owner/experimenters, 1680. Seems like a perfect candidate for 300-MP. For all the setup I do during a range visit, I like to conduct several tests before I knock it all down.
Hoot