S&W 28-2

[showme 22]

I just traded for a mod 28-2 that looks great, lock-up is very tight,everything looks great.
When I shot it ,the first and second six round groups went fine. On the third cylinder full (in single action ) things went fine till the 5th round then the hammer felt like it seized-up.about half way back.I unloaded it went thru the single action motions again and same thing, about every 4th or 5th cocking of the hammer it seems to try to lock up the hammer.
Any advice on what might be happening ?

 

[Black_Talon]

For starters:

Make sure your ejector rod is tight.

Make sure you don't have dirt/debris underneath the ejector star.