Flat-hop and R-hop are Hop up mods.
Using a Flat-nub or an SCS Nub does not make your gun Flat-hopped or R-hopped.
Buckings:
Buckings are used for three purposes:
1. Hold the Hop-up unit secure to the inner barrel.
2. Provide Hop by the rubber of the Bucking contacting the BB.
3. Provide air seal via the Bucking Lips with the Air Nozzle.
Drop-in Buckings are standard Buckings that come stock with airsoft guns. There are also after-market drop-in Buckings that you can buy that are usually better quality than the stock Bucking.
Better quality Buckings can increase range and accuracy with your gun.
Most Buckings come in soft, medium, and hard degrees.
Soft for high speed and low fps set-ups.
Medium for mid-range guns
Hard for high power set-ups.
Bucking Mound and V-teeth:
A standard Bucking has what is known as a mound.
A mound is a hump in the inside of the bucking that the BB passes over when shot. This hump is located on the Bucking directly over the barrel window of the inner barrel. When the BB passes over the Bucking mound, it presses into it as if it is flattening the mound.
V teeth are another approach/design of a Bucking mound where the mound is actually semi-replaced by twin fins of rubber. I say semi replaced because in some V-teeth designs, the V-teeth actually stand on top of a shortened Bucking mound. The idea is that when the BB passes over the V-teeth, the V-teeth will cup the BB and give the BB greater stability.
FireFly V-shaped Buckings and KWA 2g Buckings are examples of this design.
Nubs:
Buckings need Nubs to apply pressure to the Bucking.
This is always true unless doing advanced modding that may not require the Nub.
- Standard Nubs are Oval shaped.
ICS Hop Up Spacer by: ICS - Airsoft GI - the largest airsoft store on
- Specialty Nubs like the SCS Nub or X-Nubs are designed to let the BB be cupped by the Bucking mound as the BB passes over it. This gives the BB more control and stability vs Oval shaped Nubs.
SCS Nub:
Shredder's Custom Works - Shredder's Concave Spacer (SCS)
Madbull X- Nub:
Madbull Red Hop Up Bucking by: Madbull Airsoft - Airsoft GI - the
- Flat Nubs have a flat top surface and a concave base to fit into the place holder on the Hop-up Chamber Arm.
FireFly Buffer Rubber is the industry standard for Flat-Nubs.
Firefly Buffer Rubber for AEG Hard - Airsoft Atlanta
General Function of the Hop-up Unit:
1. Turning the Wheel Gears on the Hop-up Unit raises and lowers the Hop-up Chamber Arm.
2. The Nub sits in a place holder on the Chamber Arm.
3. As the Chamber Arm is raised and lowered, the Nub will pass through a cut out in the inner barrel known as the barrel window.
4. The Nub will then meet the Bucking rubber at the base of the mound.
5. The Nub applies pressure to this mound thus raising and lowering it.
6. The more the Bucking mound is pushed into the inner barrel, the more Hop is applied, the farther you shoot. The less the Bucking mound is inside the inner barrel, the less Hop is applied, the less distance you shoot.
Flat-hop:
(Credit: Star_Folder)
1. Turn Bucking inside-out.
2. Shave off Bucking mound and Bucking Ridge that secures Bucking in place on the inner barrel.
3. Turn Bucking rightside-in.
4. Use Flat Nub instead of standard Nub.
Purpose:
Allows more surface contact between the bb and Bucking due to a flat piece of rubber raising and lowering in the inner barrel vs a mound. Think of a Bucking mound as a speed bump. Think of Flat hop as a runway.
R-hop.
(Credit: hunterseeker5)
This is a patch that fills the space in the barrel window of the inner barrel. So, applying pressure with a Nub pushes on the bucking which pushes on the patch. In this case, there is no Bucking material whatsoever touching the BB, only the patch.
Basic Install:
1. Turn Bucking inside-out.
2. Shave off Bucking mound. Bucking Ridge is optional.
3. Cut the length of the patch to fit barrel window. Measure twice/cut once.
4. Sand R-hop patch Outer side to be flush with the OD(Outer Diameter) of the inner barrel.
5. Radius the trailing edge of the R-hop patch. This does not take much.
6. Sand the inside of the patch.
This where the fine tuning begins.
There are several approaches to this part to tune the patch for given distances along with given weights of BB's.
Typically speaking, a basic R-hop install sands the patch to be flush with the inside of the inner barrel as the patch sits in the inner barrel window. This is a good starting point for your first attempts at R-hop. The more experience you gain at R-hop, the better you can sand the R-hop patch specific to distance and BB weight.
Purpose:
Allows for more contact surface with the BB and the material it is contacting.
In this case a patch, not the Bucking.
This also eliminates the distance the Bucking has to raise and lower as it raises and lowers in the barrel window such as in using standard Nubs and even Flat-hop, for the patch is already at the surface of the barrel window.
Think of the R-hop patch as a runway with a ramp.