Hey there Neckringer,we had our gunsmith d&t a nef but a 12 last year for a rail and red dot.I would imagine you should'nt have a problem with a 20 due to the chamber being thicker on that model.That being said,i saw a post on the old board that nef said on their site that 12s could'nt be d&t.I asked my gunsmith about this and he said that you had to be precise on the depth as not to drill too deep.He said he had done a number of them with no problem.I've had work done by him for years and he's well respected in the area.the guy has a patent on a muzzle brake for rifles that he makes and installs so i imagine he knows what hes doing.Once my kid shows me how to post pictures we will show you his.There is a picture of one on the sights and optics page under the title "show us your halo and red dot rigs"Maybe we can get some feedback from other nef shooters on this.I trust my smith but i certainly don't want my son to continue shooting something that is unsafe! good luck and good hunting this season....ward
