Tire/Rim Question

I have a 5x10 enclosed trailer - running ST205/75R15's. The rims are rated for 1870 pounds @ 50 psi. I want to bump up to a D rated tire - rated at 2150 pounds @ 65 psi. Is there any harm in installing the 'D' tire on my 'C' rim? I'm guessing it will be fine as long as I don't pump them up to the full 65 psi - but I wanted to ask before I went ahead with the purchase.

A 5'x 10' enclosed trailer must be a single axle. I run P tires on all of my single axle trailers and tandem axle trailers under 5k-6k gross. Most P tires carry 44 psi and some go on up to 51 psi so no bead unseating worries on a lite weight single axle trailer. This way I have non of the usual ST tire issues.

The advantage of a D tire over the C tire comes at those higher pressures. Tires operate cooler when their at its max pressures.

Never over load or over pressure a wheel above the manufacturer rating. Those ratings are there for a very good reason.
Over pressure a wheel can result in the bead seat flange splitting radially with a loss of air as the tire takes on a load. BT/DT in my younger days when I was on the road.

Check out http://www.rvtiresafety.com/2013/10/will-you-increase-load-capacity-with.html from Tireman9 our resident tire engineer.

And for over pressuring a wheel read his thoughts which is common recommendations from tire and wheel manufacturers.
http://www.rvtiresafety.com/2011/12/wheel-is-just-wheel-isnt-it.html