I see no reason that Victorian Era firearms would not be adequate to the task. By the mid 1800's we already had all sorts of brass cased self contained cartridges. At that point, it becomes a matter for just a little bit of experimentation for what will work.
If you were talking about Velociraptors from Jurrasic Park (Deinonychus, probably) as in roughly human sized Therapod, Most modern hunting rounds would easily work, as would Shotguns. I would recommend a shotgun and some really solid tactics to deal with them. In fact, the tactics are going to be more important than the weapon, because you are talking about pack hunters.
For the really Big Buggers, You may want to consider a combination of a few things. What you need is the ability to penetrate a long way into a large body. A simple ball of lead may not be enough, especially with the anklyosaur. For this, you might want to consider a Flechette type round fired through a really large bore rifle (with a Sabot). This Sabot technique was known at least as far back as the 1830's. It appears to have been used to fire sub-caliber (smaller than the bore of the gun) balls. It had the side effect of a much longer range from the same gun. So drop an big arrow shaped projectile in a casing to keep it steady through the barrel and to keep the expanding gasses behind it and you get a very high velocity impacting with a very small point and, most importantly, not deforming much. This will give you MUCH better penetration.
It would also be an excellent idea to develop the dino equivalent of a bear trap to help out with these. It would probably be a good idea to slow them down enough for you to get the shot in the first place. Not very sporting, I admit. Given that a hippo is terrifying enough, now add armor and a freaking war mace. That's something like your Anklyosaur, so anything goes.
