Post #1 - The Bullet
Summary of what follows: I used the 160-grain all-copper bullet from General Bullet Co. in a repeation of the tests from the Barnes bullet in Part C. (LINK to Part C). The General bullet goes about as fast as the Barnes bullet, but is a different design and performs differently than the Barnes bullet.
First, an acknowledgement goes to forum member rohk. He started reporting his good results with the General bullets and Enforcer powder 2-3 weeks ago, so I rearranged my planned test series and tried the General 160-grain bullet.
Warning: The loads and techniques described here may damage or destroy your rifle, or cause you serious injury or death. They were OK for me, but you and I likely do things differently. These loads probably exceed SAAMI pressure specs for the 450B. Keep in mind that this report is coming to you via the internet, a prime source of misinformation.
The General 160-grain all-copper bullet, their type #45-160, is not a duplicate or clone of the Barnes GAP bullet. (LINK to General Bullet site). Like the Barnes, the General bullet has a very wide and deep hollow point, but the cavity is shaped differently and looks almost hexagonal. The external dimensions also differ from the Barnes. The General bullet is slightly longer than the Barnes. The Barnes has its greatest diameter just below the ogive, and tapers inward toward the base. The General bullet has its full diameter for most of the parallel bore-bearing sides. The average of measurements of several individual bullets is shown in the photo.
The external differences make the General bullet a bit easier to hold in the 450B case. If there were a significant internal taper of the case near the mouth then the Barnes might fit better. However, both the Hornady and Remington cases have a straight, non-tapering portion for about a half-inch from the mouth. (Maybe the Barnes would work best with an unreamed 284 case?)
The .448-inch diameter is of the General bullet less than the usual .451 or .452 used with the cartridge. So, the fit of the bullet in the case mouth will have to be monitored carefully by others choosing to use this bullet. In my trials a couple of cases had to be run a short length into the Hornady taper-crimp die before seating the bullets, in order to hold the General bullet firmly.
rohk reported that his General 160s were a uniform .451 diameter. He probably was working with a different lot of bullets, so that's something that should be checked by anyone who decides to work with this bullet.
The following photos attempt to illustrate some differences between the two bullets:
edited for grammar & spelling