Couple observations working on my 257 brass today. The Win +P brass definitely feels harder than the Remington brass. I split two case necks on the Win +P brass resizing new brass. I wish I had annealed them before resizing. Like I mentioned before, it is much more difficult to re-size the Win +P, especially on the up stroke.
Another observation is that the the Win +P brass and the Rem brass weigh almost the same. Win +P = 174.6, Rem brass 175.5. This was a small sample test since I only used one of each, but I didn't feel like ruining a bunch of primers on an extensive test when filling with water. The Win +P brass held 58.2 grains of water and the Rem brass held 56.5. This was a bit counter intuitive since the +P brass is said to have thicker walls and therefore in theory hold less water.
I got a bit of variation when measuring cartridge base to ogive for the E-tips with the Stoney Point . I measured 5 total and results varied from 2.473 to 2.483 inches. This surprised me a bit.
I also spent a couple hours annealing the hard Win +P brass. I did the candle method I read on this forum. I hope this helps accuracy. Another observation that didn't occur to me until now is that when shooting with the Rem brass I got really good accuracy. A .579 group using the Sierra accuracy load with 52.5 grains of H4350 and 100 grain MK. When loading 100 TTSX with 46 grains of Hunter I got 1.5 inch. Of course the Match Kings are noted for great accuracy, but I loaded them to book OAL and just threw 5 rounds together to see what this barrel might be capable of. I might be on to something, time will tell, but when I load up these E-tips I'm gonna use the Rem brass and see what happens. Once I hit an accurate load, I'll try the Win +P again and see how they do.
