Resident Evil 6 gameplay help thread

[TheSelfishGene]

So.
I need some help in at least one part of the game. But due to there being no prescribed order for playing through the scenarios, I don't want to go into the spoiler thread and read about something from Chris chapter 5 when I'm stuck in Jake chapter 2, and haven't started Chris' missions.

So; please use this thread to ask for gameplay tips and help. PLEASE USE SPOILER TAGS for your questions.

Here's an example, and I actually need help here - so if you can answer my question please do ^^

STUCK IN JAKE CHAPTER 2
Spoiler:

show spoiler

I'm at the part where Ukstanak is standing on ice, and I have to distract him while Sherry gets a keycard from a nearby corpse. He either goes straight for Sherry and kills her instantly; or goes straight for me and I can't react in time to dodge. I keep sending Sherry over the top near the broken ladder to the left. Should I bother doing this? I've tried about 15 times now. Help please!

[Blacktail]

There's a few remote bombs on the right side of the area, use those to distract him.

[Darkside05]

Put a remote bomb near the ladder you helped Sherry climb up, their should be a little bit of non ice floor sticking out. Then run to the other side of the cave and trigger it, she will grab the key then you can make your way through the door.

[L-e-W]

Need help with Leon Chapter 4
Spoiler:

show spoiler

When Simmons charges the train I cannot seem to aim at him, none of my shots do anything and he just kills me by ramming the train. Am I supposed to use the Sniper Rifle? If so, I'm out of ammo on that and the battle beforehand didn't give any ammo for it either. Suggestions?

[Blacktail]

I would suggest using the assault rifle, the rapid fire helps your chances of hitting him.