My Calves routine requires Standing Calf Raises and Seated Calf Raises

There is no standing calf machine at my gym, the only thing I could find was a 45 degree leg press with free weights. There is however a seated calf raise with free weights.

I'm new to working out and this was the first time I attempted a standing calf raise where you lower your ankles below the 0 degree line as far as possible and push above the 0 degree line as far as possible.

So I start with 90lbs, and I increase 90lbs each time while I'm trying to gauge my max calf for 10 reps. Well I get up to 450lbs which maxes out the leg press capacity and still no problems. Am I doing something wrong here? This just seems very weird considering everything else I do is very weak in comparison.

Seated calf raises are a little weird as well. Before I jumped on I watched a guy who was fairly built hit the seated raises at 100lbs. So I went ahead and went for 100lbs, no problem, so I bumped it up all the way to 180lbs without issue. The problem is that before you lift the weight to move the bar(stopper) the pads are not low enough for me. I could not find a cushion of any kind to eliminate this problem either. The only way I could do more weight was if I did not use the bar at all and let the weights go almost to the ground (which is now too low). So I went ahead and kept it at 180 since it was comfortable for me to use, and still be able to use the stopper functionally.

Can someone please tell me what I am doing wrong? I'm going to talk to one of the staff to see if they can come up with some options.

Thanks in advance