500 shots is not enough to break a HW in from my experience. They seem to really get sweet as you get closer to 2000 shots. A Vortek spring kit will take the twang and buzz out of it though. I had a SHO kit in my TX200 and did not care for it and installed the 12ftlb Vortek Kit and really like it. That's a different rifle from the HW50 though. You may see if the spring can be interchanged between kits on the HW50. That way you can just swap $18 Vortek springs and not have to buy a whole $80 kit. For example my TX200 I intially installed the SHO kit and was able to convert it to the 12ftlb kit just buy swapping the spring. Most of their kits this is possible but you will need to email Vortek and ask them which kits offered for the HW50 have spring compatibility.
Smooth shooting- ease of cocking-linear power = JM kits.. Far superior in my Opinion. Having used both MFG's products over the years The JM kits get my vote every time.The V-brand kits are simply too snappy and increase cocking effort...Two traits most unwanted in a 50s. The diff between the two makers is night and day. If you wish too neuter your 50s go with a 10j kit..... smooth factory power= JM.Happy Shootin!Petey