I had the same problem with my new 455.
I found that the safety was catching on the corner of the bolt when trying to push it forward.
You could see exactly where it was catching.
You will have to take the bolt apart and remove the safety lever, but, that is easy.
I took a 600 grit stone and took off the a touch, just smoothed the edge a bit, and it now works perfect.
Just don't get carried away. Just a single very light pass to smooth the edge.