Am crazy about my lightweight 20 guage Montefeltro short barrel...shot 22 of 25 trap at my local gun club this weekend from low gun position with an ounce of 7 1/2 promotional 2 1/2 drams of powder cheapy loads! (previous best ever was 16 of 25). Question: what's the least expensive extended knurled hand removable choke tube for my 20 guage Montefeltro? Thanks! DJ Dan McPhail, Flint MI