You are now in the final stages of getting your Garand match ready. Now, you are going to work on the handguards and the gas cylinder. You have already put a pressure point in the area of the lower band by using the spacer when you bedded the rifle. Your goal now is to essentially free float the barrel in front of the lower band, with the exception of where the front of the gas cylinder attaches to the barrel. You will be doing that by gluing the front handguard to the lower ring, relieving the barrel channel in the front handguard and opening the barrel opening in the front handguard ferrule and gluing the front handguard in place.
Start by cycling the action with the rifle upside down and watching for any contact places on the operating rod as it goes through the lower band and front handguard. There are a couple of easy ways to do this and the simplest is to just give a light coat of grease to the operating rod and watching for areas where the grease is scraped off. Start by removing the inner metal support of the front handguard by bending the "ears" on either end up and pulling out the whole metal support from the other end with a pair of pliers. As you will note, this substantially weakens the front handguard so you will have to be careful from now on and not handle the gun by the front handguard. Next, working with the lower band and with a good round file, remove just enough metal to give clearance to the rod. Next, you need to remove metal on the inside of the front handguard ferrule to give the barrel clearance. Generally, I like to see sufficient clearance that you can slip in a piece of card stock all away around the barrel and between it and the ferrule hole. You can do this with peening the inside of the hole in the band, or I have a tapered grinding stone that is just the right diameter that allows me to chuck the band in the drill press and take off just enough metal in the ferrule hole to give me the necessary barrel clearance without cutting the ferrule hole through. I also take that time to file the front of the ferrule square and flat with my hand file and then use a bit of touch-up bluing. Filing the front of the ferrule square also helps with the clearance you will be getting when you machine down the rear of the gas cylinder in the next section.
With the lower band in place, but without the lower band pin in, reassemble the rifle with the stock and receiver first. Slide on the front handguard to the lower band and see if you can feel any areas where it contacts the barrel and all the while, having a piece of card stock around the barrel and between it and the front ferrule hole. If there is contact, slide it back off and go to work with your round file. When you are satisfied that there are no contact points, you are ready to do some judicious gluing. First, remove the operating rod and the rear handguard and the pin from the lower band. You are going to center the lower band and handguard with the stock and gas cylinder, regardless of where the groove is cut for the roll pin. The objective is to get things straight and free floated. The roll pin groove may or may not be in correct alignment. In short, you are making the alignment of the free floated parts correct then worrying about where the roll pin inserts, rather than trying to make the alignment fit where the roll pin groove is located. In point of fact, by the time you have properly glued the lower band in place, the roll pin is almost superfluous.
Make sure the rear end of the wood of the front handguard is roughed up and free from oil and grease and that the inside of the lower band is degreased as well. Using dyed AccuraGlas, dab a bit of AccuraGlas on the rear of the front handguard, being careful not to get any on the barrel or stock ferrule. You don't need to have a lot, just a few dabs. You are gluing to "center" the front handguard at this point, not to build strength. That will come later. Then, with the rifle in a vise and the lower band locked into the stock ferrule with the receiver in the stock and tightened down with the trigger assembly (and the lower band installed without the roll pin), gently tap the front handguard into the lower band so the glass makes contact and will glue it together. Wipe off any excess and make sure none drips into the stock ferrule. With the front handguard in the lower band and before the epoxy sets, turn the rifle upside down in your vise. Put the gas cylinder on by just sliding it on, without the cylinder lock or plug. You are putting it on just for alignment purposes. Inspect the rear of the gas cylinder and make sure you align the front handguard with the rear stub that protrudes from the rear of the gas cylinder. You should be able to rotate the front handguard just enough so that it is exactly centered. Make sure that the card stock is between the handguard ferrule and the barrel, however. Set it aside and let it cure overnight.
The next day, you can take off the gas cylinder and without removing the front handguard from the lower band, gently tap off the front handguard ferrule after you remove the receiver from the stock. With a small amount of AccuraGlas, you can then glue the front handguard ferrule to the front of the handguard, and again, keeping the card stock between the ferrule and the barrel. Let it sit overnight.
You now should have a front handguard that is aligned with the stock and free floated from the barrel forward of the lower band. You are not finished yet. Next, remove the front handguard from the gun entirely. Because the front handguard is now part of the lower band, it will be necessary for you to first remove the action from the stock to relieve the pressure. You should then be able to slide it off with a couple of gentle taps. You will need to strengthen the joint between the lower band and handguard.
To increase the strength of this joint, you will drill a hole and install a 1/2" #6 wood screw on each side of the lower band running into the front handguard. This adds the needed strength. Be careful how you drill and keep everything centered. The best place to put the screws is on either side where the wood is the thickest. Countersink the metal a bit to accept the screwhead, but not too much. Then, install the screws a couple of times each to chase out the hole. Next, with a small amount of AccuraGlas, coat each screw and install it in the handguard. The screw head will protrude a bit. After the glass sets, you can file or cut it off with a Dremel tool, polish and add some touchup bluing. Add a bit of AccuraGlas to areas that did not get thoroughly glued initially, to add more strength, working it in with a sharp pointed stick. Let cure and trim. At this point, I also like to use a bit of varnish or oil to seal the inside of the front handguard.
When all of that is done and the epoxy has cured (a day or two), it is time to reassemble the gun and to permanently (almost) install the lower band with the front handguard attached. This is a two step process. First, clean and degrease the inside of the lower band barrel ring and the outside of the barrel where the two will join. Then slide the front handguard and lower band into place. Then, before you place the barreled receiver into the stock, with Green Wicking grade loctite, apply a thin film and work it in between the lower band and the barrel and wipe off any excess that may have protruded out. Before it sets, put the barreled receiver into the stock levering off the lower band and stock ferrule as you would normally assemble the gun. Lock it all down with the trigger assembly and leave for a couple of hours. The lower band should now be attached to the barrel almost permanently. You can now take the barreled action out of the stock as normal. If all has gone correctly and your alignment is true and the roll pin groove is where it should be, you can install the roll pin in the lower band at this time. If not, you will have to fill the roll pin hole with a high heat glue to insure it stays in place. The recommended adhesive is General Electric RTV-106, which withstands heat to 500° (type in RTV-106 on the Internet Search to find suppliers), or, I like JB Weld Epoxy, which has a over 600° tolerance and makes a permanent bond in lieu of the roll pin. If you use JB Weld, you should also use that for the lower band in lieu of the Green loctite. I have been able to successfully install the roll pin most of the time without having to use the adhesive. If you use the adhesive, or if you use the JB Weld, you just need to plan on replacing the front handguard and lower band when you replace the barrel. You are now done with the front handguard.
You can then turn your attention to the rear handguard. This is an easy fix. You only need to remove about 1/16th or so of the wood at the rear of the handguard, so it doesn't touch the front of the receiver when it is installed. I have found the best way of doing this is to scribe a line on the top of the handguard, then take it over to the grinding stone and slowly grind off the necessary wood. Using the grinder is, I have found, the best way to prevent it from splintering, which often happens when you attempt to hand file it and you get a faster and better job. Touch up the raw wood with a bit of walnut dye and oil and you should be good to go. You should also place a dab of AccurGlas in each side of the barrel cuts just behind the contact area for the rear handguard band, to keep the handguard from sliding back under recoil. If you wish, use a bit of release agent on the edges of the band to help prevent it from being permanently attached to the barrel.
You are now done with the handguards and ready to turn your attention to the final modification -- the Gas Cylinder Work.