208s trigger

I have a question on my 208s.  On the first shot of slow fire, I slingshot the slide, the first trigger pull of the first stage is nice and smooth.  On the next four shots it feels like more of a load.  I don't notice it on T and R.  Any ideas of what could be causing this?

Last time you cleaned your gun? Lubed sear and hammer ? How is your trigger bar ? How much movement ?

The gun is clean and lubed.  This is on the first stage before the sear starts moving.  The trigger bar is polished, underneath the bar is polished.  Must have a different reaction between the trigger bar and the slide after it fires.  Something rubbing a little more.  It's enough for me to notice.  It's the slide and trigger bar or something to do with the first stage spring... IDK

Trigger bar doesn’t contact slide until slide travels to the rear disconnecting the trigger bar from the sear. Check underneath bar for grit and make sure grip isn’t interfering with the bar. 
Jon

Looked at the trigger bar again and there was a line across it that wasn't there before.  On the inside of the slide there is a little bump.  Yea I don't know what's up with that.  But polished the trigger bar again and slightly stone the bump.  I think slow is good here.  I'll go shoot it tomorrow.
Thanks