I've had three .35 Whelens, starting with a rebarreled Mauser in the early '70s, then a rebored Rem 700, then a 700 Classic when they came out in Whelen.
I had great results with Speer 180 Flat Nose bullets in all of them and took quite a few deer with them. I also used Hornady 200 Spire Points with good results, but consider them a little 'hard' for our smallish whitetails. I also shot the Speer 220 FP, Speer 250, Nosler 225 BT and a box of Barnes 300 RNSPs, but only took a couple deer with the 250s. They did "OK", but are a little heavy for WTs and the one 250 I did recover (raking shot hit the right hip and was under the skin at the left shoulder) had barely expanded.
I had poor results with Remington 150 Spitzers, very little expansion, but I was looking for a lighter, low recoil load and found out later that they were designed for max loads in the .350 RemMag. The .35 Whelen and the .350RM are ballistically very close, but since I was trying to use lighter loads, the bullets didn't get the velocity they needed.
I never shot any 200 RN in the Whelen, which are available from several makers and designed for .35 Remington velocities. They may be suitable for lighter loads, but are probably too fragile for full power Whelen loads.
I sold my last .35 Whelen a few years ago to a friend that wanted a hammer. He only shoots deer, but believes they're tough, so the Whelen gives him the confidence he needed and he's taken quite a few with it.
I'm now in the process of building a .358 Winchester. I have a lot of .358 bullets left over and plan to use them up. I had a spare short action receiver and stock laying around and got a barrel with the idea of keeping it short and using my suppressor with it.