Excellent, good luck on the Nilgai this fall. The 220 gr Speer is a favourite for a couple of friends in a 356 and 358 on everything from deer up to grizzly and moose. Your load is not far off what they get for speed. Sounds like you have a great load in that 35 Rem that can do pretty much everything at reasonable distance. I'm going to try the 180 gr Speer in my 358 for deer this year but those 220's of yours sound very tempting for an all around load.
