It's new, isn't it? That's quite normal. It'll loosen up in time.
When I first got my PT809, the release was so stiff I got a round circle mark on my thumb after my range session from my pressing it hard. I think it loosened up a little by the 3rd range session. Works perfectly fine now.
Is the gun new? If it is, just break it in. It should get softer after 100 or so. If you are done with the breakin peroid, check if the button is harder on one side over the other. If the button is easier to press on one side try blasting the mag release latch with some gun scrubber to free up any particles causing the bind up. If it is still hard to press try to put oil in the mag release button from inside the frame. The last resort is to disassemble the mag release button and polish ONE side of the button where it contacts the latch. DON'T polish the other side. The reason for this is the button will be very easy to press. You want to keep the side of you strong hand harder to press. So if you are right handed polish the left side of the button and latch only. I polished both side on mine and cause tons of accidental mag drop because it was hitting the button with my grip. Because of this I just disabled the button on the right side. Disassembling the mag release assembly is easy but the reassembly takes some patients. That spring will be a ***** to work with. Check out the sticky for the tutorial on how to disassemble and reassemble.
Mine is stiff, too, so perhaps normal. I also have a Glock 21 with a similar magazine catch mechanism. It works hard too. I found it helpful to put some lubrication through it (any of the contact areas inside the mechanism and around the buttons). I also push up on the magazine before pressing the release. This makes it work much easier if you don't mnd this extra step. I am anxious to see if it loosens some with use. jrh
I know this tread is old now, but I have the same problem. I have a brand new PT809 Compact. When I unload it with a full mag, I have to use the butt of screwdriver to push the button in had enough to release. I've oiled the snot out of it. No help.
I had the same problem with my PT845. I shot hundreds of rounds through it, pressed the mag release hundreds of times at home, oiled it. Nothing helped. i finally sent it to Taurus, and they replaced the mag release, and now it functions as it should have from the start. I don't know why some of the 800 series pistols have had problems with very stiff mag releases. i suggest calling Taurus and sending it in. The difference is amazing.