Yes the rail should be removable but i dont know if it would have the normal Tikka scope mounts on it. As for you getting one with a 24" barrel i dont know where you saw one at but the Beretta website dose not show that they import a 24" barrel model. They ahve to models both with 20" barrles. One in 223 and the other in 308. Here is the link.

http://www.berettausa.com/product/product_rifles_main.htm