Bock,
First off, location is key. You can have the most updated, high-tech, expensive machine with all kinds of bells and whistles, but if the location isn't condusive to finding old coins, you won't find any, simply put.
To answer your question regarding the abilities of the Ace 250...yes, the Ace 250 can and will find old coins. BUT- keep in mind, the Ace 250, although a great machine, has its limitations, in regards to target separation, depth, and overall versatility. You should definitely be getting more than two inches with it, though, even with a small coil such as the Sniper.
One of the reasons a lot of people are finding the coins they are is because they are able to get around trash and/or iron that masks a lot of the older coins. These coins are not easy to find with your average detector, and many old timers missed these ones in the past, dismissed as trash targets. You'll see examples of coins that are found with rust stains, indicating iron was present. Some are simply too deep and underneath bottlecaps and pulltabs and nails and bits of wire and canslaw and bobby pins and cans...you get the idea. There is a reason why a lot of these guys here that are so successful in this hobby spend over a grand for a detector that can get around these obstacles and snag deep elusive silvers, indian heads, etc.
Having said that, I have found some silver coins with my Ace 250. However, I only use that machine for the occasional tot lot hunt nowadays. It hits great on shallow coins and it is great for small gold or foil. It is not the best at separation, and having only two tones doesn't help it's situation. Since I upgraded, my success rate has vastly improved, and I don't even use a super duper expensive detector, just one with more options.
Your best bet is to find an area low of trash, like the woods. Very few signals in comparison with say, a park, but a higher ratio of good finds to trashy finds. Hit me up one day if you'd like to get together some time, maybe we'll hit a spot or two that can give up some silver for you. Just remember, the Ace 250, though a great machine, is NOT a Minelab Etrac.
Joe