Why not - you just need to prepare 50 posts in notepad and post them every 15 seconds, 30 seconds, or 1 minute between posts on the thread you want. If you really do it - then I'm sure you can probably post 50 posts in less than 1 hour. Such posting patterns may be rare - but burst posts are always possible among spammers who don't care about quality.

Burst posts are about the interval between posts - but if all the posts created are quality posts, then I don't agree that they are considered burst posts. I don't focus on the interval between posts as long as the posts are meaningful - so I tend not to check who is doing it other than reporting low quality posts if I find them.