Hoping to get some advice on how to properly secure my safe in its location.

My safe is on the second story, so obviously there is no concrete base to anchor it to.

The safe is on carpet and can be anchored to the sub floor and/or floor joists.

I'm thinking about cutting the carpet out where the holes are pre drilled on the bottom of the safe, so the carpet does notch catch and pull away when the drill is used.

The sub floor is 3/4" plywood.

What screws or bolts are best for my application? 2" lag bolts?

Thanks in advance for your input.

The safe holes probably wont line up with the floor joists, and may be hard to located their centers to install lags into them.  You can use something like this flip anchor through the subfloor.  I would probably drill through back of safe and put a couple lag bolts into the studs also.
http://www.sigtec-f.com/en/flip.html

 
 

It's a good idea to try and get anchor bolts into the floor joists. Those rarely end up in the right places to line up with anchor holes. Good anchor strength is a big part of good security. When a safe can be put on it's side or back, burglary attempts are far more successful. 3/4": plywood may sound strong, but not really. When you have a 5-6 foot tall safe, you have a lot of leverage to push/pull and tear out anchors. A long pry bar under the edge with a close fulcrum point will pull even 1/2" or 5/8" bolts right out of 3/4" plywood real easy.

There are several ways to make this all better.

1. Drill some holes thru the back or side and lag-bolt into the wall studs. You can do this without making a mess if you use a large fender washer of steel plate over the holes. You may need to provide some shim blocks under the bolt-points against the wall so the safe is level.

2. If you have access the dead-area between the floors, use big machine screws (1/2" - 3/4") and place a large flat plate with the nut/lockwasher underside so there is a large bearing area to resist bole pull thru.

3. Place a thick sub base, maybe 3/4" good quality marine plywood under the safe. Use large flat-head wood screws anywhere you can get into the floor joists. This provides a much stronger foundation to then lag-bolt your safe down.

4. Same as #3, only use a steel plate, lag bolt it into the joists, and use machine-bolts into threaded holes in the steel plate.