Rotary Hop-Up Maintenance & Service

The ALPHA, TRIDENT, War Sport LVOA and GPR-CC, Barrett REC7 series, and the KRISS Vector series use the same rotary hop-up unit. The TRIDENT 47 uses a similar design but in a different form factor to accommodate the AK-style magazines, but the below instructions will still apply.

The P90 also uses a rotary hop-up unit but of a different design. Please see the P90 Hop-Up Maintenance & Service page for more information.

This guide will help you identify the parts of your KRYTAC rotary hop-up unit and how to correctly disassemble it for maintenance and service.

Hop-Up Unit Springs

The KRYTAC rotary hop-up unit consists of the the hop-up unit itself and a pair of springs.


The wider diameter of the two springs may not always come out when you remove your hop-up unit, so be sure to check inside the base of the outer barrel if this is the case.

Both springs are required for correct operation and performance, so don't lose them!

Lifting the Tension Arm

Lifting the tension arm will give you access to the hop-up "nub". This is the part that presses in on the hop-up bucking as you increase the amount of hop.

To lift the tension arm, first turn the hop-up dial until position 0 lines up with the indicator mark.


Press the top part of the hop-up dial away from the tension arm.


While holding the dial in this position, lift the tension arm.


Cleaning the Barrel

With the tension arm lifted, you may safely clean your barrel.

To clean the barrel, you will need the included cleaning rod and some clean, lint-free patches. "Small bore" cleaning patches are available at your local sporting goods store.

Make sure that the cleaning patch is appropriately sized. If it's too large, it will require excessive force to push through the barrel, and you may risk damaging the hop-up bucking. If it's too small, it won't be able to pick up the dirt from the barrel.

Insert the cleaning patch into the looped end of the cleaning rod. Run the cleaning rod in the direction of BB travel; insert it into the opening of the hop-up unit and push it through to the front of the barrel.


Remove the dirty cleaning patch, replace it with a new one, and repeat until the barrel is clean.

Hop-Up Unit Disassembly

To remove the inner barrel from the hop-up unit, first remove and set aside the two hop-up springs if you have not already done so.

Give the barrel a slight twist. This will disengage the lock on the barrel clip. After disengaging the lock, you will notice that the barrel clip is no longer flush with the hop-up unit. You will be able to easily remove the barrel clip without damage.


Remove the barrel clip, then slide the inner barrel out of the hop-up unit. Typically the hop-up bucking will come out along with the inner barrel.

When installing the inner barrel into the hop-up unit, first install the hop-up bucking onto the barrel. We do not recommend using any lubrication as this will have a negative effect on the hop-up function. Ensure that the hop-up bucking is seated correctly and that there are no folds or other errors.

Next, make sure that the barrel is oriented correctly so that the "window" is lined up with the hop-up nub. You can test this by installing the barrel and reassembling the hop-up unit, adjusting the hop-up to its maximum setting, and looking into the barrel through the hop-up unit. If you do not see the hop-up bucking extending into the barrel, set the hop-up to "0", remove the barrel clip, and rotate the barrel 180°.

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