M16/22 SD By Joey Buddafuco

Ever notice that despite the variety of machine guns at a machine gun shoot there always seems to be one machine gun that draws a crowd? Getting bored with your M16? Looking for a new conversion for it? Are ammunition expenses keeping you from shooting your beloved toys? Does the0 local range ban center fire, rifle caliber machine guns? These questions have plagued the civilian machine gun owner since the machine gun was first invented. The M16/22 project is the answer to these problems. The M16/22 conversion will increase the pleasure of shooting and owning your M16 and the best part is you can build it yourself! The M16/22 never fails to draw a crowd at the range. The quiet little buzz gun quickly becomes the center of attention and the most requested to be shot machine gun. The shooter quickly notices the absence of recoil and noise. An extended burst, usually 30 rounds, can be placed on the desired target with ease. An ammunition cost of less than 60 cents per magazine may allow you to encourage new shooters to machine gun ownership without putting a dent in your budget. In order to maximize the shooting enjoyment of the M16 with a 22LR conversion, you need a dedicated upper receiver for it. You also need a way to make the conversion unit reliable. Unreliable guns are frustrating and quickly become unused guns. A dedicated upper receiver can be assembled using many of the parts you already have around the shop. Why a dedicated upper receiver for the 22 LR conversion? When firing 22 LR ammo through a 223 caliber upper, lead builds up at the front of the 223 chamber, in the bore and in the gas take off vent. This lead buildup can result in dangerously high pressures if you fire a 223 without thoroughly cleaning it. A separate upper for the 22 LR conversion allows you to quickly change between calibers without having to worry. The dedicated upper also allows you to have a configuration not possible with a 223 upper.

Items required to get started: 1. M16 or AR15 with registered sear. 2. Atchisson 22 LR conversion for the M16 currently manufactured by Jonathan A. Ciener. 3. Barrel, preferable a slow twist one. (1 in 12) 4. Flat top upper receiver. 5. Standard components for the upper, i.e. ejection port cover, forward assist, and cocking handle. 6. Aluminum carbine hand guard. 7. 5.5" Flash hider. 8. Suppressor (type discussed later). 9. Optical sight. Required tools: 1. Basic gunsmith tools. 2. A metal lathe with thread cutting tool and gears (or a gunsmith/friend you know who has one). --------------------------------------------------------------------------------

Getting Your 22 LR Conversion Kit To Work Reliably First you need to get your 22 LR conversion kit to function reliably. The Atchisson 22 LR kit manufactured by Ciener is ammo sensitive and not reliable as it comes from the factory. This kit needs some minor work to improve its reliability. Start by disassembling the kit. Clean it thoroughly, and use a mild abrasive metal polish like Flitz ™ to remove the rough exterior caused by the parkerizing. Do not remove all the finish, just get the exterior smooth to the touch. Reassemble the kit and try it for smooth functioning in the upper you are planning to use. The inside of the upper might have burrs that can effect performance. The anti-bounce weight needs to run smoothly in the upper since it seems to cause the most drag. Remember NEVER shoot in full auto without it. The greatest source of feeding problems seems to be the feed ramp. Tool marks from the factory can make it very rough. This ramp needs to be cleaned up and polished, but be careful. There is not enough steel to make a mistake, and the factory will not honor the warranty if the purchaser modifies it. You cannot erase all the tool marks. Simply smooth the ramp as much as possible without removing excessive metal. Lightly polish the chamber to remove the parkerizing from it. DO NOT round the chamber edges or you will have case head blowouts. This last modification may not be necessary. You can judge what your machine gun requires. The stamping/cutting process that forms the plate the bolt rides in may have slightly warped it. If this has happened it can be straightened while using a machinist's metal straight edge for comparison. The magazine needs to be inspected and kept unloaded since the feed lips seem a bit tight and may possibly be damaged by being loaded over a prolonged period These modifications can make this kit 100% reliable with all types of 22 LR high velocity ammunition. One additional modification is to make a 1/8" thick buffer from 65 durometer urethane rubber. The buffer is inserted against the rear plate in the kit. The buffer removes the "clack" that you hear when the unit is fired. This buffer also increases the cyclic rate some, not considered detrimental in a 22 LR subgun. You can make an additional lighter recoil spring for the unit so that you can shoot 22 CB Longs through it. These make the gun into a super-quiet submachine gun with enough energy to smite any vicious soda can that comes into range! -------------------------------------------------------------------------------- Designing Your Upper and Making Your Barrel The type of suppressor used will affect your design the most. You might try a S.C.R.C. Mk 24 D .223 suppressor. This suppressor is designed with a two point lock-up to keep it aligned with the bore while firing. The suppressor consists of a 14inch long steel tube with stainless steel baffles. This is very effective at suppressing the 22 LR when shooting with a 20inch barrel. To build a dedicated 22 LR suppressed upper that is more compact and impressive looking, just make the barrel mate up with the suppressor so that the rear collet is not needed to keep the suppressor aligned. For instance, you could use an extra Colt 20inch light-weight barrel with a 1 in 7 twist that you have left from another project, and have it cut down for this one. The dimensions for machining this barrel are shown in Figure 1. Do not cut the barrel shorter than the aluminum handguard if your suppressor will not fit inside it. This is where your design may vary. The barrel is cut behind the gas port, which is not needed for the 22 LR, and the outside is machined to the profile shown in Figure 1. The threads and the lock-up surfaces must be turned true to the bore, not the outside of the barrel, since the bore of a rifle barrel will probably have some runout between the chamber and the muzzle. Photograph 2 shows the finished barrel with 22 LR ONLY engraved on it, which designates that it should never be used with 223 ammunition. Since the barrel is hidden under the handguard and finish is not important, you may just cold blue it for rust protection. The machining of the barrel's exterior would not be required if you are going to use a single point lock-up suppressor or a quick mount system like GemTech's M96. The threads would still have to be cut concentric to the bore regardless of the type of suppressor. You could always use a 3-lug adapter or 1/2" x 28 thread to mount a 9mm suppressor. The problem with a 9mm suppressor is that the efficiency is low. This is a cheap option if you already own the 9mm suppressor. DO NOT shoot 223 through a 9mm can though, since they are not designed for the pressure and could burst.

Download the Files for Weapon Plans

1 AR15

2 AR360

3 45Mac

4 22 Rifle

5 5 Lead Dead Rifle

6 50mm Rifle

7 6mm Rifle

8 AK58

9 SKS128

10 Afao Sniper Rifle

11 45mm Automatic

12 70mm Grenade Launcher

13 40mm Assualt Shotgun

14 22mm Pistol

15 SKS200 Rifle

16 Mac and Johnson Lead Rifle

17 River Bandit Shotgun

18 Hech and Trech MP34

19 Mossberg Automatic bolt rifle