Fellow Shooter,
The load was a 300 Grain Remington, with an appropriate dose of H110. If any of you want to discuss load numbers, I will, but I just do not like to post powder levels on the main board. Just drop me an IM.
I have to admit, it was a great killing shot, but not a great aimed shot. They were so close, and things happened rather quickly. I was zeroed for 200 yards, and the shot was aimed perfectly for a 100 YARD SHOT. Consequently, I hit him high, in the spine. Needless to say, he dropped like a brick. There is not enough width on an antelope to stop any bullet, so I have no idea what the bullet did, other than the fact that it did it's job. He was not quite dead when I got to him, so I put a finisher in him, through the heart. Another pass through.
I will probably be switching bullets to a Nosler Partitiion. Not because the Remington will not work, but because I might end up pointing the gun at a bear or muley or elk, and I want to make sure that I have a premium bullet. I will play with the Barnes bullets this winter, and see how they work. I am still unsure as to whether the BC gain in the 300 XSP will be worth it for me. It has a narrow expansion window, and it might be acting like a FMJ beyond a few hundred yards. Fine for paper, not so good for critters.
I have had my best groups using H4227, but the velocity is well off where I should be able to get with my 20 inch barrel. I actually had a 3 shot 100 yard group that measure less than a quarter of an inch with the H4227. I have not found a great grouping load with H110. I picked up a couple of pounds of H4198, and that is my next project.
As to barrel break in, I am a little unsure about that. I am an avid accuracy shooter, and know the drill. I just am not sure if it is worth it with a premium barrel. There is certainly nothing to loose, by doing it. I had very little time and brass to do it with this upper, so I opted not to. It does not seem to have caused any issues.
All in all, am am very pleased with Marty's creation. He did a wonderful job on my upper, and is an absolute joy to work with.
Gotta run, I have a new Aimpoint that that I need to get on my upper. I would suggest that any of you who are thinking about any optics for your 458 that are not "premium" might want to rethink it. I have a broken Bushnell Red Dot, and Vari-X II that did not make the grade.
CRaig