If it's wet snow, you need to keep it loaded up good, ie: keep it moving fast. Most single stage ones seem to want to plug easily if conditions aren't ideal.
JMHO,
Mike

Does it seem like the belt is starting to slip under load? Possibly a belt adjustment? I'm unsure what snow thrower you speak of...

Actually, I was wrong. I have the Ariens 520 Compact, but it doesn't have the pistol grip handles...just a bar grip on each side. Everything else is the same. Shows you how much I know about this stuff.

See link

Here is a link that might be useful: mash here

As previously suggested, I'd check the belt adjustment as per your manual. You might also try spraying the chute with cooking spray such as Pam. This sometimes helps with wet snow.

Okay, will try that. Thanks.