PolarStar JACK™ Nozzle
PolarStar JACK™ Nozzle
For cylinder conversion systems, PolarStar assigns numbers to nozzles instead of using the rifle model. Nozzle length can vary between the same gun model when made by different manufacturers — due to differences in design or gearbox shell thickness affecting how far the cylinder sits from the hop-up chamber. A standard MP5, for example, could require any of 4 different nozzle lengths depending on manufacturer.
Once you determine your replica's nozzle number, that number is universal across all engines using the numbered system (excluding some model-specific Kythera™ systems). A #11 nozzle works across JACK™, F2™, and other numbered systems.
Formula for Custom Measurement
If your gun isn't in the compatibility database, measure your gearbox using calipers in thousandths of an inch (0.001") and calculate:
JACK Centerline Nozzles: TIP = F + B - (A/2) - .0875
The measured tip length should be within ±0.010" of an existing nozzle to be compatible. Contact us with your measurements for custom orders.
Compatibility Chart
| # | Most Commonly Used With | Tip (in) | OAL (in) |
|---|---|---|---|
| 1 | TM M4/M16, A&K PKM, TM MP5 A/SD, ICS MP5 A/SD, G&G KAC SR-25E2 | 0.8245 | 1.677 |
| 2 | CYMA AK, CYMA MP5 A/SD, G&G UMP | 0.8625 | 1.715 |
| 3 | CA M249/MK46, A&K M249/MK46 | 0.8095 | 1.662 |
| 4 | G&G GR-25 | 1.4505 | 2.303 |
| 5 | A&K SR-25, JG SR-25, ICS SIG 550/551/552 | 0.9635 | 1.816 |
| 6 | KA FAL, TM MP5K, A&K M240 | 0.8945 | 1.747 |
| 7 | PTS MASADA, CA SCAR-L | 1.1345 | 1.987 |
| 8 | VFC SCAR-H | 1.5075 | 2.36 |
| 9 | EF/S&T TAR-21 COMP | 0.8765 | 1.729 |
| 10 | EF ARX160 ELITE | 1.4865 | 2.339 |
| 11 | CA KAC LMG, VFC MP5 A/SD | 0.7475 | 1.6 |
| 12 | LCT AK-47/74/M, LCT VSS/AS VAL | 0.8355 | 1.688 |
| 13 | A&K MASADA/ACR | 1.3465 | 2.199 |
| 14 | KA CZ 805 BREN, CG M249 FEATHERWEIGHT, A&K M60 | 1.3895 | 2.242 |
| 15 | EF/ARES G36KV/CV, JG G36 | 1.0545 | 1.907 |
| 16 | EF/S&T G36C | 1.0415 | 1.894 |
| 17 | CA AUG | 1.0045 | 1.857 |
| 18 | G&G MP5 A/SD | 0.795 | 1.647 |
| 19 | VFC/ECHO1 XCR | 1.227 | 2.079 |
| 20 | CA G36, CYMA SR-25 | 1.026 | 1.8785 |
| 21 | Elite Force/CYMA MP5K, CA SA58 | 0.923 | 1.771 |
For a full compatibility database, visit the PolarStar Help Center.
