Doc, yes, this 99-A is 1-10" ROT and the 87 gr Speer HotCor is the second most accurate bullet tried in it. The Sierra 90 gr HPBT is the most accurate bullet, but i don't trust it on deer.
100 gr bullets are not as accurate in this rifle, so I went with the 87 gr HotCor and found it killed every deer I hit with it. My reloads with H4895 average 2925-2950 fps and on occasion I have put it into the shoulders with good results. I have used the bullet in a .257 Roberts at 3200 fps and if put into the shoulders it did not perform as well and required a second shot a couple of times, so I moved up to 100-115 gr bullets.
