Do the CMP shoots have different 'classes? In other words, Iron sights, Scopes, Barrel Lengths, etc.?
Can I shoot my 14-1/2" M16A1 carbine, semi of course?
If so, would I be competing with 20" Bbl., shooters?
Also, is it "off hand" or, from a rest?
Thanks,
John

CMP I don' know how the matches work but you can look around on the CMP site.  I'm sure one of the guys will answer your question better.

The match formats generally consist of multiple positions.  The ones I have competed in consisted of the following:  10 shots off-hand slow fire, 10 shots prone rapid fire, 10 shots sitting rapid fire, and 20 shots prone slow fire.  I think there may also be a 30 round version, but I'm not sure.

Also, the ones I have done required that all rifles be as-issued military rifles of WWII or earlier vintage, so I can't help on the AR portion of your question, except that I'm almost certain that there will be no scoped rifles at all.

Thank you, gentelmen. I'll check out the cmp link.

Im going to a cmp shoot tomorrow. They said I can use my A3 Bushy. I will let you know about it as soon as I can. I take it you are on a quest for a garand like me.

Quoted: Im going to a cmp shoot tomorrow. They said I can use my A3 Bushy. I will let you know about it as soon as I can. I take it you are on a quest for a garand like me.

Actually, I don't want to have to buy another rifle. to do this.  

The CMP shoot was fun. The format was as har4 explained above. They had range owned garands there  that you could use, but at this particular club you could use any military style weapon even ones that are foriegn i.e. ak47 SKS etc.. It was very relaxed    no pressure to perform and everyone was very helpful. I recomend you go to one. I will go back as soon as my schedule allows. I dont know where in pa you are but if you are in the pittsburgh area I went to the Pitcairn-Monroeville Sportsmans Club. They have a cmp shoot the first sunday of every month and you dont have to be a member(there is a small fee).

Quoted:
I dont know where in pa you are but if you are in the pittsburgh area I went to the Pitcairn-Monroeville Sportsmans Club.  quote]

I'm in the S.E. (Delaware Co,) but the range I frequent has CMP. Thank you for the description, I'll try it.
John