Hop-up chamber for M249 - metal 2nd GEN (CNC made) Precision Type (moRRisCZ) - EPeS

- Successfully tested in CA and AK M249 in combination with 30+ types of hop-up rubbers (Falcon, Systema, A+, CA, AT, GD, MB, Element, RA, Guru, ICS, GP, MapleLeaf, JBU, PDI, SHS… from each manufacturer all available hardnesses) - in most cases, tests achieved performance exceeding spring power by 10 m/s, or higher (without chamber sealing and further tuning)
- Recommended nozzle length 21.4-22 mm (depending on the internal configuration of the gearbox – feeder arm, cylinder head, piston gear cams ensuring higher nozzle lift…) - optimal length 21.7 mm

Key product advantages:
- High quality and precision of manufacturing, used high-strength duralumin 7075 T6 (not anodized to maintain high manufacturing tolerances and sufficient surface hardness)
- Ingenious internal shape for the hop-up rubber collar
- Internal barrel fixation using 4 blunt grub screws (unlike standard fixation using a latch, it allows axial barrel movement – better hop-up rubber seating and slight axial barrel correction)
- Modified position and size of the BB feeding port (higher compatibility)

The hop-up chamber allows for individual adjustment, which can help eliminate manufacturing inaccuracies in some Chinese-made parts and weapons and brings a few user benefits:

• possibility to define the clearance of the chamber in the gearbox using the included O-rings (2 different sizes)
• removable/replaceable pin securing the chamber in torsion, if necessary, a longer one is included (to remove, just heat it with a heat gun or hair dryer) - some M249s have a problem with this, due to different dimensions and seating of the part that ensures the feeding of bullets to the chamber - into which the chamber, or the pin described above, fits
• 3pcs pressure rollers (various lengths 4.2-4.7 mm)
• bonus worm ensuring a more perfect chamber in torsion - for M249s that are assembled with a fixed outer barrel (cannot be quickly removed, barrel is screwed with longer screws from the side of the body) - the worm is screwed into the thread in the upper part of the chamber - in some cases it is necessary to partially adjust the groove in the body guns
• groove allowing partial fixation of the chamber and inner barrel in the barrel housing, or rather the outer barrel – for M249s, which are assembled with a removable outer barrel (the chamber with the inner barrel holds the outer barrel in place after removing it from the body guns )