I am wondering if this is realistic and hope that fodorites familiar with LGA can help me.

I am scheduled to arrive at LGA on 12/28 at 10 a.m. at Terminal M. Then I need to get my bag from baggage claim before checking in again for another flight leaving at 11:55 a.m....this flight is a Delta Comair flight and I'm not sure which terminal it leaves from. Since these are not connecting flights, my concern is whether I will have enough time to get my bags from baggage claim and go back through security in time to get to my 11:55 flight. Please don't suggest that I just take a carry-on because that is not feasible for this trip. Thanks!

You should be fine.

Even if they are not connecting, if you booked the tickets together, they may still check your luggage all the way through.

Are you traveling into LGA on a different airline than Delta? (I assume you are.) If so, call them, or Delta, and ask if the two airlines have a "luggage agreement."

If they do it probably won't matter how you booked the flights. You simply ask the first check-in agent to route the luggage all the way through to your final destination.

The first flight is from Continental into LGA & the second is a Delta flight. I will ask the first agent at Continental to route my luggage through to my final destination. Sounds Easy Enough! Hopefully all will go smoothly and I will have luggage that afternoon when I arrive home! THANKS!!!

Delta and Continental are codeshare partners, so I don't think checking your bag through will be a problem.