Milofficer
CGN Regular
- Location
- Vancouver, BC
FAQ posts exist for all the other popular NR rifles, so I wanted to put one together for the RDB based on my experience as an owner and after talking to the gunsmiths at Vault, the Canadian importer and warranty center.
If the mods would be so kind to sticky the post like the other FAQs, that'd be great.
Getting Started
If the mods would be so kind to sticky the post like the other FAQs, that'd be great.
The Basics
- Your RDB is held together with HK-style push pins. The three push pins in the receiver are longer than the push pin in the handguard. The shorter handguard pin is not meant to be interchangeable with the receiver pins. It'll fit, but it's too short to be properly secure.
- Your push pins should push out from left to right. When your rifle is ready to be disassembled, your pins should be hanging out the right hand side of the receiver. The retaining clip for the push pins is only on the right hand side. If the pin direction is reversed, they may not be captured properly and might walk out during use. I have even seen the pins completely seized when they were inserted the wrong way.
- The push pins can be completely removed from the receiver, but be gentle in doing so to prevent damage to the pins and the retaining clip. Ensure that you re-install the pins from right to left.
- If you have difficulty tapping a frame pin out, try standing the rifle on its butt and pushing all the modules (grip, receiver, barrel assembly) downward to relieve pressure on the pins. Bashing the pins out can damage the little retaining clip and they are a bear to replace.
- The cheekrest screws have a tendency to work loose over time (see the first picture below). It is highly recommended to use red (preferred) or blue loctite to keep these screws secure.
- Periodically check the screws on the optic rail for tightness. The screws are somewhat soft, so don't overtighten and be sure to use the correct size tool for the job to prevent stripping. Once you have verified the optic rail screws are secure, use a witness mark using a paint pen or nail polish to indicate their position. If you notice that the screws have started to come loose, it might be time to re-apply some high temperature threadlocker. Use heat and a properly sized tool to remove the screws. Clean them as best you can, and apply some high-temp threadlocker, making sure to re-apply witness marks. Follow curing directions as required by the threadlocker manufacturer.
- Periodically check the two screws hidden under the rubber butt pad for tightness. These can also work loose over time and loctite is highly recommended.
- From Vault: Some firing pins can be a bit on the brittle side. It is highly recommended that you do not dry fire your RDB unless you are using a Snap Cap that cushions the tip of the firing pin. Dry firing can shorten the life of the firing pin dramatically. It is good practice to check on the firing pin when cleaning. Contact Vault if you need a replacement.
- From Vault: There is some confusion about .223-marked RDBs imported for the Canadian market. After emailing Kel-Tec directly regarding this issue, we have confirmed that these rifles are chambered using a 5.56 NATO reamer. The .223 barrel marking is a holdover from certain US export regulations.
- From Vault: One final note – the exploded diagram in your manual will show a Firing Pin Spring. This is a holdover from the first iteration of the RDB – your RDB doesn't have a firing pin spring, so don't worry, you didn't lose it. The bolt and firing pin have been redesigned to eliminate the spring, so there is no way to retrofit one at this time.
Getting Started
- The RDB doesn't require much lubrication, but a little goes a long way to keep the rifle operating reliably. The main points for lubrication are on the bolt carrier raceway where it interacts with the receiver rails. Use a good quality oil or grease on these rails, making sure some gets on the cam pin. I personally prefer Slip 2000 EWG grease since it stays put and seems to smooth things out.
- As your rifle gets used and broken in, you may notice some finish wear on other operating parts. If you like, you can put a thin film of oil on these areas to reduce friction. Some finish wear is normal.
- If you are hitting the range for the first time with your RDB, go through the Gas Adjustment Procedure on Page 7 of your manual. It probably will work right out of the box, but it is good practice to adjust your RDB for the conditions and your brand of ammo.
- Unlike an AR-15, the RDB is meant to be tuned for your conditions and the ammunition you are going to be using in your rifle. Not all ammunition is the same, and pressure curves can vary greatly between manufacturers. Outside temperature can also play a part. The RDB allows you to adjust exactly how much gas is going into the system. If you follow the gas adjustment procedure, your rifle will be operating with just enough energy to function reliably without excess recoil. This will also reduce wear and tear on the operating components.
- When a round is fired, high pressure gas is tapped off into the gas head through a small port in the barrel. The gas head is open at both ends – the end facing the shooter contains the piston, and the muzzle end contains the vent hole. By turning the adjustment knob clockwise, you are reducing the size of the vent hole, allowing more gas to act on the piston. If you turn the knob counterclockwise (ie, unscrewing towards the muzzle), you are increasing the size of the vent hole, reducing the gas acting on the piston. Keep in mind that the adjustment knob gets very hot during use, and should be adjusted using a cartridge tip or gloves.
- If you are planning to store the RDB for a period of time, or if you haven't cleaned it in some time, you should remove the piston from the gas head for inspection and cleaning. Some types of ammunition can leave deposits in the gas head that build up over time and can degrade performance. Using a good solvent on the gas head and piston can help. The piston should be easily removed but shouldn't drop freely out of the gas head. If the piston is very difficult to remove, you might have a damaged gas ring. Check the gas rings for damage when you are cleaning. Likewise, if the piston fits too loosely, the gas rings should be replaced. They use standard AR-15 gas rings.
- When reassembling the RDB, ensure that the tail end of the action spring rod is 'nested' in the pocket of the buffer located at the rear of the receiver before closing the rifle.
- You can use the front of the bolt carrier to visually check if the RDB is fully in battery. It is best not to 'ride' the charging handle when chambering as this can sometimes prevent the bolt from fully locking into place. By pulling back slightly on the charging handle, you should be able to visually check if the carrier is fully seated or not. You can also use the position of the carrier to quickly check if your rifle has locked back on an empty magazine or not.
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