I used a hacksaw to cut the barrel. The first thing I did was to cut the bayonet lug off with a dremel tool. Then I removed the grenade sight.Then I took some electrical tape and taped as round asI can where I wanted to cut the barrel to remove grenade launcher.This is so that I had a guide to cut with my hack saw. Make sure to use a brand new blade , the shortest blade that will fit your saw and use a fine tooth blade. Then I took a fine file and removed the sharp edges on the barrel. Also past the file in a circular motion on end of barrel to smooth the cut and make sure it is square. Then I took a pointed grinding stone for my hand drill and add some polishing compound on the grinding stone. Then I lightly and slowly cut a crown on the end of the barrel. Being a sks I figured that the crown I give it should be good enough. Then I degreased the end of the barrel and cold blued all the cuts. Now you can also nock the pin out on the grenade laucher and thread it off. I think they are right hand threads. Use a penatrating oil and tap on it before trying to remove it. You may need a vise. I cut mine off so that I did not have to deal with them threads.The barrel is a little lest than 20". I wanted to cut it at 16.5" but I would then have to taper the barrel to get the front sight back on. The rifle balances a lot better now. I also removed the rubber butt pad and added a metal butt plate. I added my scope tonight and also a buffer. Friday I hope to take it to the range to see how she shoots. I will shoot with the gas valve closed so to save on my cheap scope.When hog hunting it will be in the semi auto mode. I will do a range report of the green monster and if everything is ok I finish up all the little odds and ends on it.