Bobby
Gonna need you to follow the sticky guidelines for filming, man. Landscape (if possible) so we can see everything. You're knees are cut off in this. Also, don't wear all dark colors as the sticky says.
This weight is too heavy for you to fix what you're going to need to fix. Drop back to 275 and film a set of 5, following everything laid out in the sticky, then post. If the bar is sliding around on your back you'll need to get one with a center knurl or make a center knurl with a little bit of athletic tape. That may be what's pissing off the elbows.