I think any of the 3 would have more than enough accuracy for HFT. I do agree with Scott on the regulated part, a low extreme spread is critical when shooting field target. From my experience two things that I have found important on a HFT rifle are shot count and ease of power adjustment. Being old and forgetful I find rifles that can comfortably shoot an entire match on a single fill are a real help. Not having to worry about getting your rifle filled during a match removes one distraction that you don't need. Being able to easily adjust your velocity can be a huge plus. All of your dope will be calculated using a specific velocity, it is not unusual to travel to a distant match and find out your velocity has changed by 20 or 30fps. Being able to quickly and easily change your power is a really nice feature. Of the 3 rifles you list I know the FX400 will meet all of my criterea. I shot a non-regulated 400 for a while in HFT and did extremely well with it, I wish I had kept it and put a regulator in it.Good luck on your decision, I think the 3 rifles you listed are all great rifles and any one would get the job done. Jim in Sacramento
I have a royale 400 and I love it. It is .22 and I don't use it for field target. Having said that, have you considered an Air Arms S500? Easy to add a Lane regulator and you could be in for a few hundred less and put it towards a better scope. I shot HFT with the AA and I wouldn't trade it for anything. As much as I love my FX, even if it was in .177 I still would pick the Air Arms for an HFT match every time.