FX Wildcat M3 Noises?

Just picked up a Wildcat MK3 in .22 which has some odd sounds. Most every time I break a shot there is a bouncing / rattling sound in the action close to my ear. It is the same on all 7 hammer settings. However, sometimes it is quiet and just goes thump like a well tuned / harmonized rifle. The rifle arrived with the reg set on 100 bar and is 100% stock. Just wondered if this is the norm with WC’s?
 
That ping sound is the hammer hitting the valve an inch or so from your ear. Very normal for bullpups! Only bullpup thus doesn’t that that long sound in your early is Impact. I highly recommend wearing ear plug in your right ear when shooting the WC.

It’s not the ping sound of the hammer that I hear it’s after that. It’s a bouncing sound and as others noted it may be free floating hammer bounce. I just don’t understand why the sound is not consistent from shot to shot shooting from the bench
 
I don’t hear it on my .25 WC. It’s raining today. So I went in the basement and shot 3 mags over the chrony. No hammer noise or other tings or clicks. I do have it set pretty heavy shooting 33.5 slugs at 900 fps. Getting 40 shots before it falls off the reg which is set at 145. Maybe the louder muzzle blast covers up the rattles. Could be shooting lighter pellets or at a lower speed lets you hear more of the hammer noise.