I am used to a free floating barrel on my Rapids and I have run a HW100 with the clamp removed and it was fine as the barrel is located pretty firmly in the action.. Will it work? The answer is 'I don't know' but barrel clamps can get disturbed or knocked and as stated by Jon, removing it and testing is a zero-risk strategy so you might just as well do it. A few minutes work and nil financial outlay has to be worth while. In any event if it isn't the clamp is will probably end up being diagnosed as the barrel itself which will cost you a few bob to get fixed. It is certainly also worth checking that the two parts of the action have not become loose. One of the major criticisms of the HW100 is that the block is in two parts bolted together with not particularly heavy duty 4mm hex bolts. They shouldn't be loose but again always worth checking when you have the action out of the stock.