1. Yes, you can use the same barrel for both. Short barrels are often used for turkey because they are easier to move around in heavier cover. I've shot a few turkeys with a 28" barrel and I've taken one with a 24" barrel, both were equally effective. Longer barrels are usually better for waterfowl because they swing a little smother for wing shooting. The biggest thing for turkeys, or for anything really, is to know your pattern density at given distances.
2. Defintely Yes!!! OFM tends to use a lot of grease in their guns and you will eliminate a lot of common issues if you clean it out and and use a thinner lubricant.
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