Hello, I am awaiting the arrival of my Fatboy 64 this week. The safe will go to the basement and I plan to bolt it down. I have used wedge anchors on some projects in my basement. It is easy to install and is very strong.  People also recommend the sleeve anchor which I have no experience of using. The last type is the drop anchor. In my last home I used the lag anchor to bolt my Stack-On and Sentry steel cabinets onto concrete floor. With drop-anchor like the lag, it is easy to unbolt the safe from the floor. Once the screw comes off, the lag stays flush with the floor allowing the safe/cabinet to be moved easily.  I used lead lag anchors before, but I understand they also make steel lag which is supposed to be stronger than the lead one.  

The wedge anchor is probably the strongest  but it will leave a stud protruding off the concrete floor. This will prevent the safe to be moved easily even after all the bolts have been unfastened.

Any experience/tips/thoughts on the most suitable type of anchor for an 880 lb safe?

Type of anchor is all personal preference.

I hate sleeve anchors. They never set properly nor do they hold well.

Wedge anchors are nice and strong but you do end up with a bolt protruding into your safe.

I have never used any drop in anchors. But looks like you have to have a special tool to install them.

Another anchor you might want to look into is a double expansion anchor. They are the ones I prefer to use. Here's a link to some.

Use large diameter tapcons.  They are installable from inside the safe and removable.  

Large Diameter Tapcons

I used these Hilti Anchors

I like this, but it requires a setting tool. I checked at my local HomeDepot and they don't sell the setting tool. Will check Lowe's and perhaps Ace's.

I used Red Heads fro Home depot. I got the biggest thing that would fit the holes in the bottom of my safe.

Kept hitting rebar drilling holes and wore out 3 bits drilling 4 holes.

We have tested a bunch, and the 1/2" LDT is the one that is hardest to pry out of the floor.

The "setting tool" is nothing more than a smaller diameter rod that fits inside the center hole of the anchor.  When you drop the anchor into the hole, you put the rod into the achor and tap it down to the bottom of the hole.  Just a small piece of allthread or punch will work fine.  Also, make sure you don't drill all the way through the concrete with this type of anchor.

I am going to give THESE a try.  Got it from Lowes.  End result will be nothing protruding into the safe once your remove the main bolt if moving.

http://www.simpsonanchors.com/catalog/mechanical/titen-hd/index.html

I got mine bolted down tonight. I used 3/8" x 3" LDT I picked up from Lowe's. Easy to install, removable, and very strong.

I used large red head anchors from home depot also and seem plenty strong.