Thought you might be interested to have a look at my latest project - fitting a heavy BSA match grade barrel to an S400 action:
Close up of barrel showing crown and heavy profile.
Initial accuracy tests are encouraging with this 5 shot group fired off a bench rest at 50 metres (the coin is about the same size as a R1 coin). There was a slight wind blowing hence the small amount of lateral stringing.
With a tuned action the rifle is delivering 95 shots with an ES of 19 fps and shot to shot variation around 7fps from a 180 Bar charge.
<span class='smallblacktext'>[ Edited ]</span>