Is it possible that I can become a Marine Recon/Raider being prior service Army?

Why would you want to? Recon Marines leave the Corps all the time to join the Army. We have better training, better missions, and all around better opportunities, funding, and utilization. While I was a Career Counselor in Okinawa, I received phone calls on a weekly basis from Recon Marines asking how to switch over and try out for SFAS or 75th Ranger. You'll find lots of former Marines in both of those organizations.

Have fun being a Private again. I had about 4 prior service army guys at PI and 2 of them went from e5 in the Army to E2 in the corps. But only way to know about being prior service is talking to a marine corps recruiter.

One of the issues you'll face is the drop in rank. Not only will you have to go through boot camp, the highest you can possibly leave boot camp is an E-3. Then you'll go through SOI and after SOI you'll try for Recon. If you pass, you'll go to further training, if not you'll most likely become an 0311. In order to to go Raider A&S you have to submit a package and do a physical as well as a psych screening, but you already have to hold an MOS and as far as I know it's not a guarantee on a contract like Recon is. Being prior-service won't place any restrictions on recon/MARSOC other than the fact that the Crops might not be accepting prior-service enlistees, or you'll be limited by what MOS you can hold being prior-service.