Being asked to compare a BAT Tactical to a Lone Peak Fuzion is a very tall order... and it's one that might just be nearly impossible to answer honestly via a simple forum post. To properly answer this question would require a 1-on-1 phone call about the specific application you had in mind and the rest of the components you planned to use, as well as a multitude of other variables. Having said that... I'll take a stab at it. Just don't ask me to defend it...
because I will NOT. For that, you'll need to call me.
BAT Tactical, fully nitrided, all integral, is one of the nicer actions I own. The model I have was purchased from Wolf Precision back when they were the singular source for that all integral fully-nitrided option. The extraction is a sako-style I think... which is basically my only gripe with it. Pretty weak extraction with lackluster ejection. However, I'm told you can get a completely nitrided version these days with the mini-M16 extractor... which would be much better. The rifle is an absolute laser in 22BR. I've handled a few rifles built on these actions. Proper stuff, no doubt.
The Lone Peak Fuzions of today are also extremely nice. All integral, nitrided, mini-m16 extractor, etc. They look great, feel great, and have outstanding customer service (which you're unlikely to need.) This might cloud my decision a little bit, because I know Brian and Mike at Lone Peak a little bit... and they work with several of my other allies in the industry. There is literally nothing that I don't like about the Lone Peak Fuzions I own and have used. I've done load workups with a pile of these things, and they leave a smile on my face every single time.
There are simply
not too many actions that check all the boxes for me. Reliable. Light bolt lift. Consistent and uniform ignition. Properly timed ignition (or easy to make that way). Reliable and strong extraction. Smooth bolt throw and feeding. (ability to cycle the action without violating NPA) All integral rail and lug. One piece bolt/handle. Ability to handle some dirt. Ability to handle some frost. Rigid and strong, meaty actions.
The three main actions I would consider for a build today are the Lone Peak Fuzion, BAT Tactical, and Impact. (their respective flagship actions) If I didn't know the guys at Lone Peak... it would be a VERY hard decision. Having said that, I choose Lone Peak for almost all of my builds these days. If I were building a BIG bore setup, then BAT is basically the only real option at the moment. So if I can find a Lone Peak configured how I need it... that's what I choose. If they don't have it... I'll probably look to BAT. (though I stay away from their non-nitrided offerings)
I know that might not be the conclusive answer you were looking for... but I honestly think it has more to do with your rifle builder than it does either the Lone Peak Fuzion or the BAT TR (tactical nitrided). As long as your smith can tune ignition and confirm either action is functioning reliably... then you're almost assured of success. TS Customs built both of the rifles above, and both rifles are absolutely ruthless in the prairie dog town. I can call Travis @ TS Customs, talk over a rifle build and he'll send me an order form with everything I need on the action already filled out. It's as simple as dropping a check in the mail to Lone Peak with that printout, and I'm done. If raw accuracy/precision was the deciding factor on a square range with optimal conditions... I might be tempted to say the BAT just might have an edge. However, I'm a field shooter... and I honestly don't think I'm leaving anything on the table with a Lone Peak Fuzion in the accuracy/precision department, and those actions are very tough and can handle the elements like a champ. I also prefer their bolt handles/knobs over that offered by BAT.
So if you were to pin me down and
force a choice out of me with the threat of pain and death, I'd choose Lone Peak. After all, I was one of the very first people here to talk about Lone Peak. They have listened to advice from myself as well as my allies in the industry, and are avid precision hunters as well as field tactical match shooters. Quite skilled ones at that. It's just an easy company to support. Perhaps that will change in the future, but that is how I see it today.