"Service Rifle" is a CMP sub class correct?
It is an NRA Highpower subclass, open to M1, M1A, and AR15 rifles. The AR needs to be an A1 or A2 (ie, have a carry handle) with a 20" barrel, and look externally like a M16A2. The most important thing for an AR is a float tube under the handguards, so when you sling up in prone position, the pressure from the tight sling is on the float tube rather than the barrel.
The full course of fire at my local club is 20 rounds slow fire, standing unsupported with 2 sighters, 10 rounds standing to sitting rapid, with 2 sighters, 10 rounds standing to prone rapid, with 2 sighters, and 10 rounds prone slow fire, with 2 sighters. The rapid stages have a reload, with the first magazine loaded with 2 rounds, and the second with 8 rounds. The slow fire stages, and sighters for the rapids, the target is pulled and marked/scored between shots. For comparison, the 600 yard target used for prone slow fire has a 12" 10 ring, and a 6" X ring. The 200 yard reduced version of the same target has a 3.79" 10 ring, and a 1.79" X ring, and the 100 yard version has 1.75" 10 ring, and a .75" X ring
The full course of fire, standing and sitting are shot at 200 yards, prone rapid at 300 yards, and prone slow at 600 yards, but there are reduced/scaled down targets for shorter ranges. The local ranges only shoot at 200 yards.
The aiming black on the targets is ~6 MOA. The full dimensions of the targets are available in the NRA rule book here:
http://www.nrahq.org/compete/RuleBooks/HPR/hpr-w04.pdf