b]Part 1[/b]
(NOTE: My reports in this thread are based on my bolt rifle, using a barrel that likely does not conform to SAAMI specs for the 450B. If you try to duplicate what I describe, do not expect similar results. Do not forget that this is internet information, which very often does not resemble reality.)
In Chap 4, I indicated three possiblities for exploring solutions to the problems of erratic performance obtained in Chaps 1-3. These three were mechanical (e.g. crimping), using powders faster than Lil'Gun (e.g. Blue Dot), and using hotter primers (e.g. LR primers in modified 284 cases.)
This report is of some results with hotter primers in LRP cases.
I gratefully acknowledge the kindness and thoughtfulness of BD1, who furnished some 284 cases that he had fully prepared for use with the 450B. He described his techniques in some June 22 posts on the "284 to 450B cases" thread in this forum. He indicated the cases he sent me had been fired once or twice. THANK YOU, BD1!.
BD's cases measured 1.700" long, +0.000", -0..002", which is pretty precise. Level full, they held an average of 55.1 grains of my lot of Lil'Gun. My 2X-fired factory 450B cases held 58.6 grains, which indicates there's some extra brass in the 284 cases somewhere.
I loaded three trial series of cartridges. Each series was made of five single cartridges having 42, 44, 45, 46, or 47 grains of Lil'Gun powder. The first series was put into factory 450B cases, primed with CCI BR4 small rifle primers. The second series was put into the converted 284 cases, primed with Federal 215M large rifle magnum match
primers. These rank pretty high on most charts that rate "hotness" of primers. The third series was put into converted 284 cases, primed with CCI 200 large rifle primers, which are usually noted for being fairly "mild".
I selected the charges based on previous experiments, reported in Chap 1. The 42-4 series included the loads with about the highest velocities obtained with Lil'Gun. It started low enough, I thought, to find if the LR primers produced pressure problems, so I could end firing a series without damaging pressures. The upper end of the series I hoped would run high enough to allow the LR primers to demonstrate their superiority to the SR primers, if indeed they were superior.
I did not put in more than 47 grains, because that load left a seated bullet directly on top of the powder in the 284 cases. In the 450B cases, some air space was present, equivalent to about 3 grains of powder.
As in other trials, I used the 185-grain Hornady SWC fully encapsulated bullet. These were seated to a COAL of 2.000", and taper crimped to a case mouth diameter of 0.476".
(Continued in next post.)