I have had a number of enquiries recently asking how to de-tune the XS78 / QB78 for indoor range target shooting. I have suggested cutting down the hammer spring a little at a time until the desired power is reached. Many thanks indeed to P. Huk who supplied the following information having worked on his gun to achieve this. Apparently removing approximately 2 coils bought the muzzle energy down to around 6 ft lbs. This result may vary from gun to gun slightly though thanks again to Pete for supplying this information.