My son is going to start shooting air rifle silhouette this year. He uses a CZ TS200 PCP for 3-P NRA Matches and it's incredibly accurate. Would this rifle be well suited for silhouette at 800fps?

At 800 FPS it would work for Open Class.

Here's the link to the NRA rule books.
ppkny


http://www.nrahq.org/compete/nra-rule-books.asp

3.3 Silhouette Air Rifle:
(a) Target Air Rifle: Any unaltered factory target air rifle designed for U.S. and International 10 meter
competition. (i.e., as produced or sold by Anschutz, Beeman, Crosman, Daisy, Feinwerkbau, RWS, Steyr
and Walther). Use of scopes or iron sights, including diopter sights is allowed. Any older gun may be
brought up to current factory specifications using only factory catalogue barrel weights.
(b) Sporter Air Rifle: Any unaltered factory sporter air rifle that is or was a catalogue item, readily available
over the counter to the general public, weighing no more than 11 pounds, with scope and mounts. Rifles
utilizing pre-charged systems of any kind other than 12.0 gram disposable C02 units are prohibited.
(c) Open Air Rifle: Any air rifle weighing no more than 16 Ibs. with scope and mounts. Length of barrel and
action measured from the rear of the metal action or air chamber to the end of the muzzle, including any extension, must not exceed 40". Rifle may utilize any self-contained or externally-charged compressed air
system, but such system must be completely self-contained at time of firing. Hook buttplates are
prohibited. All air rifles not meeting Rules 3.3(a) or 3.3(b) will be fired in the Open Air Rifle class. The
storage of reservoir tanks for either compressed air or C02 is prohibited on the firing line or in adjacent
spectator areas. (See Rule 9.9.1.)