Updated August 2026
Uni-Loc® Weight Cartridge Guide
Predator cues made since 2008 use the Uni-Loc® Weight Cartridge System, letting you fine-tune your cue's weight without tools or losing its balance point. This guide covers how the system works, the available cartridge sizes, which cues are compatible, and how to adjust your own cue.
How the Uni-Loc® Weight Cartridge System Works
The weight cartridges sit inside the cue butt, under the bumper. Because the bolts have no head, they can be stacked to combine sizes — for example, a 0.5 oz bolt plus a 0.2 oz bolt adds 0.7 oz. Stacked bolts need to be tightened firmly together, or they can buzz during play.
- Precision: adjustable in increments as fine as 0.1 oz (2.83 g)
- Combinations: 8 cartridge sizes give up to 30 possible weight combinations
- Installation tool: dual-prong tool with a detachable handle — use by hand for on-the-go tuning, or with a drill bit for faster adjustment at home
- Maximum addable weight: 3.5 oz (100 g) combined at one time
Weight Cartridge Size Chart
| Ounces | Grams |
|---|---|
| 0.1 | 3 |
| 0.2 | 6 |
| 0.3 | 8.5 |
| 0.4 | 11 |
| 0.5 | 14 |
| 0.7 | 20 |
| 1.0 | 28 |
| 2.0 | 57 |
How to Adjust Your Cue's Weight
- Unscrew the bumper on the end of the cue butt to access the weight cartridge cavity.
- Check whether a weight bolt is already installed — many cues ship with one, since natural wood-weight variance sometimes requires a factory-added bolt to hit standard weight.
- Remove any existing weight and weigh the bare butt and shaft separately with a scale (a Pelouze scale or comparable) to find your cue's true dry weight.
- Add or stack cartridges to reach your target weight, tightening stacked bolts firmly.
- Reinstall the bumper.
Standard and Custom Weights
Predator's dry cue weight is typically around 18 oz — about 14 oz in the butt and 4 oz in the shaft. At checkout, new cues can be customized to 18.5, 19, 19.5, or 20 oz. Predator does not sell weight bolts separately from the cartridge kit.
Choosing the Right Weight for Your Game
Most players fall between 19 and 21 oz. A heavier cue carries more momentum through the break; a lighter cue offers finer control on precision shots.
Weight bolt size for Predator cues pre-weight cartridge system (before 2008)
The Uni-Loc weight cartridge system has been used on P3 cues since 2008, and then used on all Predator cues introduced since 2008.
If you have a Predator cue that was made before the current Uni-Loc Weight Cartridge System and you need a replacement weight bolt. The thread size is 3/8x16 and the head style is flat. You can find it in a local hardware store or you can order it from our website here:
Which Cues Are Compatible?
| Cue Series | Weight Cartridge Compatible | Notes |
|---|---|---|
| 8K Series | Yes |
No longer available - please see 10K Series cues |
| 9K Series | Yes |
No longer available - please see 10K Series cues |
| BK III Series | Yes |
No longer available - please see BK4 Series cues |
| Blak 2, 3 & 4 Series | Yes |
No longer available - please see Blak 5 Series cues |
| CRM Series | Yes | |
| Ikon 2, 3 & 4 Series | Yes |
No longer available. See the cues in our Archive |
| Roadline – Sneaky Pete Series | Yes |
No longer available. See the cues in our Archive |
| P3 Series | Yes | |
| SP6 Series | Yes |
No longer available - please see SP2 Series cues |
| Throne Series | Yes |
No longer available. |
| Limited & Special Editions | Yes |
2012 and newer only |
| BK Rush | Yes | |
| All Predator Carom Cues | Yes | |
| Molinari by Predator Carom Cues | Yes |
Made before 2019 only |
| Cues Made Before 2008 | No |
Use a different sizing system — see "Weight Bolt Sizing for Pre-2008 Cues" section above. |
Uni-Loc® Weight Cartridge Questions
Eight sizes: 0.1, 0.2, 0.3, 0.4, 0.5, 0.7, 1, and 2 oz — giving up to 30 possible combinations for fine-tuning.
Yes. Since the bolts have no head, they can be stacked to combine sizes — tighten them firmly together to prevent buzzing.
Up to 3.5 oz (100 g) combined at one time.
Any Predator cue made in 2008 or later uses this system. See the compatibility table above for specific series.
Pre-2008 cues use a different weight bolt sizing system. The thread size is 3/8x16, and the head style is flat. You can find it in a local hardware store, or you can order it from our website here:
No — weight bolts are only available as part of the Uni-Loc Weight Cartridge Kit.
The Uni-Loc Weight Cartridge Kit's installation tool, which has dual prongs that interlock with each weight and a detachable handle for use by hand or with a drill.
