BCNW

I recently purchased a used Performance Shop 828u. Love everything about the gun so far except for the trigger. Feels rather spongey and creepy. Since I don't know the history of this gun in terms of how many shells have been put through it, I'm curious if this is how all of these triggers feel or if there is something I can do/replace to make it better. I already tried cleaning and re-lubricating the trigger group, but did not solve the issue.Do they smooth out over time? Don't care about lightness, just want a clean break. Thanks in advance for the help.