"...Who manufactures "Maverick"?..." It's a low end Mossberg M500. Exactly the same gun with a low end synthetic stock. Nothing 'new' about 'em though.
No 3" magnums out of an 88. A 2.75" magnum will be fine, except for the pain shooting 'em out of a 7 pound shotgun will cause.
http://www.mossberg.com/category/series/maverick-88/
Wearing out the barrel is just silly. Nothing to wear out in a smooth bore.