This is a post about integrally suppressing the Ruger 10/22 Rifle.If you ever wanted to see what a suppressor looks like on the inside, here is one example. Although there have been varied means and methods and posts on it in the past that were detailed at the SilencerTalk board, I have attempted to do it in the easiest way possible. It takes a lathe and I used a milling machine, but the mill could be substituted with a simple drill press if one has the skills. This method takes several hours but the results are well worth it. This particular design has been tested against several commercial designs and the general consensus is that it is at least equal too, or quieter. I’ll put up a few videos of it and let you be the judge.
This is what can be done once the Form One is in hand. Of course, the usual disclaimer applies here. If you don’t have the proper paper work, don’t mess with it. It just isn’t worth the possible 10,000 fine and 10 years in jail if you get caught with one. Pay the 200 dollar fee and you wont have to look over your shoulder every time you move it or shoot it, and you can show all of your friends how cool it is without worrying about someone ratting you out. Look at it as 200 worth of insurance to keep you out of jail. Now that we got that out of the way, it’s on to the build.
Here is the first picture. This one is of the barrel . It’s showing a 6″ deep hole that was drilled with an 11/16 drill bit. It just so happens that 11/16 is the tap drill size for a 3/4-16 thread. Since we are trying to keep this easy, the internal thread will be tapped with a tap and this will hold the cap which retains and centers the guts. It’s not much to see really, just a barrel with a hole with 3/4-16 threads in it, about a 1/2″ deep. When drilling the barrel, its important to not go too fast on the RPM’s and to keep the barrel as cool as possible. Most gun barrels are 4140 and they are heat-treated, so the metal is pretty tough. Just keep it under control and don’t let the chips bind up in the barrel. Now that we’ve got the barrel drilled out, we’ll go ahead and tap it. It’s a good idea to use a starting tap, and to use the tail stock to keep it centered up. Go about a half turn then back it out,and repeat the process until you are about 1/2 to 3/4 deep. Depth doesnt really matter as long as it’s a good fit for the cap. When you get done with the starter tap, run a bottoming tap in it and go to the depth of the original thread. The starter thread will only have about two good threads in it and the bottoming tap will clean out the whole depth and give you several good threads.
Now we are on to the baffles, or in this case it’s a monolithic baffle stack. This was made out of aluminum to keep it light, but anything will work. The baffle stack is about 6″ long and it starts out life as a 3/4″ outer diameter. The holes you see are just 9/16″ holes drilled through it and the center hole is .280 thousanths which gives plenty of clearance for the .22 bullet to pass through without fear of baffle strikes. The center hole must be machined first and its a good idea to drill from both sides of the part since most of you wont have a long enough drill to do it. Use a good center drill and drill from each side to ensure that the hole will be straight. Take your time, keep the chips clear and be sure the drill is sharp and has good geometry so that it doesnt wander off center. Once you get the center hole done, you can concentrate on machining the ends of the mono stack. One end of the stack, the back-end, will be machined on a taper to fit the drill point. Most drill points are 59 degrees or 118 included angle. Machine the part to fit on the taper of the drilled hole and this will held to center up the baffle stack, which will be turned later on for clearance.
The other end of the baffle stack will rest in the cap,and will have a smaller diameter with a shoulder on it that tensions on the cap. The diameter in the cap is 1/2″ and its about .125 deep. As long as the baffle stack is a good fit into the end of the cap, the size doesnt really matter. Just keep it easy and use diameters for tools that you already have.
Now on to the machining of the baffle stack. Measure the final length and divide the number of holes that you would like to use. In a 6″ long stack you can see that I used 9 holes because that’s the way it came out. Those holes are 9/16 inch diameter. Use a center drill before drilling each hole to make sure that the drill doesnt try to “walk off” on the diameter. Take your time and do it right. It can be in a mill or a drill. I did mine in a mill using a digital readout, and it only took me about 10 minutes to drill out. A drill press will take a bit more time but the result is the same. You’ll notice that the holes are round and the baffle stack is relatively uncomplicated compared the M,K, or Vbaffles and all of the other designs that look fancy. Fact of the matter is, the .22 doesnt need it. Those round holes cause the gases to converge on themselves and cancel each other out and it works very well. Of course you can make the M,K,V or any other design baffles that you want to but it wont be any better or quieter.
Now we make the cap. The cap OD is the same diameter as the barrel, in most cases the bull barrels are .920. Machine the threads to make a nice fit into the barrel, using the barrel as the gauge because we used a standard tap and we want a standard cap thread. Machine the shallow hole in the cap to fit the smaller diameter on the baffle stack. When the cap is finished, its a good idea to put some form of holes for a spanner wrench to help loosen it up later on down the line because .22 ammo is filthy and will weld the thing together if you don’t take care of it.
Here is the tricky part. The cap must tension the baffle stack so that it is centered up. By centered up, I mean that with the clearance of the monolithic baffle stack to the drilled hole in the barrel. I chucked up the mono stack in the lathe and cut it between centers and gave it about .032 thousandths of clearance. This helps to remove any misalignment and to help disassemble it for cleaning when you’ve shot a few hundred shells through it. It is important to put it between centers and take the skim cut. Dont try to make it too tight a clearance, more is better here and it doesnt seem to affect the sound at all. Ok. We have done all of the above, everything is nice and concentric, the stack is tensioned and we are ready to shoot. After experimenting with several subsonic brands, CCI subsonic seems to work the best and be the most consistent and it is very accurate. Listen closely to the videos. The bolt slamming back and forth is fairly loud, and if you pay attention you can actually hear the hammer whack the firing pin on the empty chamber on the last shot. The bullets are hitting a paper target and the bullet strike is very obvious. All in all, I am very pleased with the performance, the can is easy to maintain and keep clean and the barrel is engraved on the bottom so that unless you look that the front cap, most people wont have a clue that they are looking at a suppressed rifle. This thing could be the ultimate squirrel killing machine and it’s fairly easy to make. Here is one of my rednecked buddies shooting it.
What d’ya think? Not bad for free…not counting the 200 bucks for the tax of course…