I'm having trouble pulling of viscerals reliably. I can get enemies stunned but sometimes it's a crapshoot if I can pull off the visceral. Hitting it immediately is too fast, but waiting one attack beat can be too long. Any advice?

When an enemy is staggered you go right in his grill, like if you were trying to give it a big hug and press R1. Make sure you are as square as possible to the front or the back of the enemy and as close as possible.

You definitely need to wait a second before you can pull it off. Attacking immediately won't work. Usually if you stun an enemy and run right up against him and hit R1, it will work. The important thing is to be right up against an enemy. Also, stairs can be finicky whether they let you do it or not so be careful with that.

The most likely reason you're not always getting the attack is probably because of verticality. The game really doesn't like it if you're not on a somewhat flat surface.

Thanks for the help, I'm getting them much more reliably now.

You just need to give it a sec. It's not too long, they'll be down for 2,5-3 seconds in total I'm estimating. If you attack after one second, that's still fine. I found you can stagger them from a slight distance, dash in and still pull it off effectively.

If you're not getting it, you're probably too fast rather than too slow.

Also, I think you need to not be on the movement stick. When you initiate the attack, I'm reasonably certain the animation only pops if you're standing still.

I always forget to use these attacks, because I'm always two handing my axe. I rarely use the gun.

This