Lost about 50 fps in my fairly new 2300kt???

[wahoowad]

I've shot about 15 cartridges through my 2300kt since I got it 3 months ago. Initially my first 10 shots per cartridge were between 500 - 475 fps, and not hitting 450 until around the 25 shot mark. Today I popped a fresh cartridge in and my first 10 shots were all around the 450 - 440 fps range. What gives?

All I've done is adjust the spring adjuster all the way down to get a decent trigger pull, and polished the sear/trigger surfaces. I checked the trigger stop screw and it does not make contact with the trigger. I am suspicious of hammer drag only because I don't know what else it could be...but not sure what could be causing hammer drag anyway 

Also...I was surprised at the standard deviation during that recorded shot string...19.3 fps, at times it was of course more. Is this normal?

[woody67]

Was it colder out than normal while you were shooting?

Temp makes a difference...

[wahoowad]

yeah, could have been 20 degrees warmer back in June. I would only expect to lose 20 fps then, right?