Most tubes are fit in two locations, choke and chamber. If the chamber is slightly loose, you can lightly put some Nail polish on the chamber(you skeet haters will enjoy this) and tap it in. This also works on fitted tubes that have lost their interference fit from years of use. Ultimate Ultra-lights are around 1800.00 dollars, if they fit your gun give the guy a fair price, I don't think 50 cents on the dollar is fair to the seller.