Roostguards for bigger guys?

Try a xx L ,  Lucky I had mine on, I did tear the webbing from impact. Broke 7 ribs on back left side , pucntured lung, hole in it created massive pressure inside my chest. Left side of neck swelled out 5 inches, jaw to eye 4 in, eye swelled shut. My shoulder was a weird numb pain& my 1/2 in plus spur on top was gone. Flight for life died in icu a few times, unimaginable pain in the chest. 5 days in trauma tying to seal the hole.  And no broken bones. 3 rotator cuffs tore , 1 strained, cb joint, etc,etc 5 of my ribs r separated yet & knifing in good just by moving my arm. Just got from the y , I whirl pool & move arm in the pool.

The HRP flak jaks are adjustable. 
Make sure you have made it as large as possible. 

Fly makes the oldschool style in an xl size specifically. I like mine.

I am 6 foot and 300lb. I have a Thor XL chest protector and I just got a HRP XXL chest protector in May. The HRP fits me best and is most comfortable. Like R66 said, make sure you adjust it to make it as large as possible. Once I adjusted mine to make it as big as possible, it fits me way better than my Thor chest protector. I am not sure what else is out there in a XXL size for us bigger guys, but I would like to hear some other thoughts on bigger chest protectors also.

I use the alpinestars bionic action chest protector and it’s great. Comes it two sizes M/L or XL/2XL.

I’m not as big as you but still a big guy and it fits me with plenty room to spare. You would definitely fit.