Systema PTW / Celcius CTW / G&D DTW Chamber Packings
The Systema PTW and its relatives (Celcius CTW, G&D DTW, A&K STW / K4-STW) run a proprietary hop-up chamber that shares nothing with the standard AEG one. It also uses its own vocabulary: the rubber that grips the BB is the CHAMBER PACKING, not a bucking, and the part the hop adjuster presses onto it is the ROLLER PACKING rather than a nub. Searching for a bucking will not find the part you need.
Also searched as: PTW chamber packing, CTW chamber packing, DTW chamber packing, roller packing, PTW hop up rubber, PTW packing base, training weapon hop up.
Commonly confused: these do NOT interchange
- AEG buckings A standard AEG bucking is not a drop-in for a factory PTW chamber. The only route to AEG-standard rubber is a PTW-to-AEG conversion hop-up chamber, which replaces the factory unit entirely. A handful of packings are cut and sold for both PTW and AEG, and those appear on both pages.
Proprietary & exception chambers
- PTW, CTW and DTW share the same chamber: Systema PTW, Celcius CTW and G&D DTW hop-up chambers and packings are cross-compatible, which is why retailers routinely list one part for all three. A&K built its STW and K4-STW to the same pattern. The one caveat worth knowing: tolerances vary between makers, and some Celcius units sit slightly short, so a cylinder shim or washer is sometimes needed to get a proper air seal after mixing brands.
- Chamber packing, roller packing, packing base: Three separate parts, all called packing, and they are easy to confuse. The CHAMBER PACKING is the bucking equivalent: it is what the BB touches. The PACKING BASE is the seat the chamber packing sits in. The ROLLER PACKING is the nub equivalent: the hop adjuster presses the roller, the roller compresses the chamber packing. A roller packing is normally sold with a fit pin, and aftermarket steel or CNC rollers exist purely to cut friction in that mechanism.
- Who makes PTW packings: Systema itself, plus Deep Fire, Orga, RWA, Alpha Parts, TNT and MAG. Orga sell a flat-hop adjuster paired with a flat packing, and MAG sell CNC stainless curved rollers. Celcius part numbers cover the CTW side.
- Adjuster kits are deliberately not listed here: Several listings bundle a hop adjuster, a roller packing and a fit pin together, and TNT sell whole TW retrofit kits. Those are chamber hardware, not a consumable packing, so we hold them off this page rather than mixing assemblies in with the rubber. If you need the adjuster itself, search the hop-up chamber categories instead.
Showing 22 of 22 buckings
Deep Fire New Hop Up Chamber Packing for Systema PTW
Systema chamber packing for PTW
SYSTEMA roller packing for PTW
Systema PTW Chamber Packing Base
CELCIUS Chamber Packing ( CTW )
![Systema PTW M4 / M16 Chamber Packing Base [BR-024]](https://www.begadi.com/media/catalog/product/cache/3b2a3d82558e21037f95df541f435f4c/b/-/b-systema-br-024-chamber-packing-base-g.jpg#p=systema-ptw-m4-m16-chamber-packing-base-br-024)
Systema PTW M4 / M16 Chamber Packing Base [BR-024]
Deep fire Chamber packing for systema PTW
Bucking / Air Seal Chamber for A&K Systema S&T CTW STW PTW AEG Rifles
Deep fire Chamber Packing base pour PTW
Systema Chamber Packing Base for PTW
TNT Airsoft H.L.R. Sniper Bucking for Airsoft AEG Rifles - PTW / 50 Degree
TNT APS-X Hop Up Rubber Bucking - PTW / AEG Series
TNT Airsoft H.L.R. Sniper Bucking for Airsoft AEG Rifles - PTW / 60 Degree
MAG CNC Stainless Steel Curve Roller Packing for PTW (Parts:
MAG CNC Stainless Steel Curve Roller Packing for PTW
Deep Fire New Hop Up Chamber Packing for Systema PTW
Systema Air Seal Packing for PTW
![[Systema] Roller Packing[For SYSTEMA PTW M4 Series]](https://cdn.shopify.com/s/files/1/0483/0642/1921/products/9921__Systema__Roller_Packing_For_SYSTEMA_PTW_M4_Series_1.jpg?v=1609905044#p=systema-roller-packing-for-systema-ptw-m4-series)
[Systema] Roller Packing[For SYSTEMA PTW M4 Series]
![[Systema] Chamber Packing Base[For SYSTEMA PTW Series]](https://cdn.shopify.com/s/files/1/0483/0642/1921/products/Systema_ChamberPackingBase_ForSYSTEMAPTWSeries.jpg?v=1610611883#p=systema-chamber-packing-base-for-systema-ptw-series)
[Systema] Chamber Packing Base[For SYSTEMA PTW Series]
![[Systema] Chamber Packing[For Systema PTW Series]](https://cdn.shopify.com/s/files/1/0483/0642/1921/products/DPFE-CPO54_MARK1_faf911f8-28e7-4b67-8e91-caf84abe93ba_800x600a.jpg?v=1655713192#p=systema-chamber-packing-for-systema-ptw-series)
[Systema] Chamber Packing[For Systema PTW Series]
![[RWA] Hop Up Bucking[For RWA PTW CNC Precision Adjustable Hop Up Set[3pcs/Set]](https://cdn.shopify.com/s/files/1/0483/0642/1921/products/RWA_HopUpBucking_ForRWAPTWCNCPrecisionAdjustableHopUpSet_3pcsSet_2.jpg?v=1622429237#p=hop-bucking-rwa-ptw-cnc-precision-adjustable-hopup-set-3pcs-set)
[RWA] Hop Up Bucking[For RWA PTW CNC Precision Adjustable Hop Up Set[3pcs/Set]
Orga Flat Hop Rubber for Orga PTW Flat Hop up Adjuster
Systema PTW bucking buying guide
Search for packing, not bucking
The PTW ecosystem almost never uses the word bucking. If you search buckings you will miss most of what fits. Search chamber packing for the rubber, roller packing for the nub, and packing base if you are replacing the seat as well.
Know which of the three you need
A worn or torn rubber where the BB sits is a chamber packing. Inconsistent hop or a gritty adjuster is usually the roller packing. A packing that will not seat squarely points at the packing base. They are cheap enough that people replacing one often buy all three.
Mixing brands
Cross-brand fitment between Systema, Celcius, G&D and A&K is normal and generally works, but check your air seal afterwards rather than assuming it. A short unit is fixed with shims, not with a harder packing.
If you want AEG rubber in a PTW
That means a conversion hop-up chamber, not a bucking swap. Converting gives you the whole AEG bucking aisle and its degree choices, at the cost of replacing the factory unit. Decide which route you are on before buying rubber.
Frequently asked questions
Can I use a normal AEG bucking in a Systema PTW?
Not in the factory chamber. The PTW hop-up is proprietary and takes a chamber packing, not an AEG bucking. Fitting AEG rubber requires a PTW-to-AEG conversion hop-up chamber, which replaces the factory unit.
What is the difference between a chamber packing and a roller packing?
The chamber packing is the rubber the BB touches, so it is the PTW equivalent of a bucking. The roller packing is what the hop adjuster presses onto the chamber packing, so it is the equivalent of a nub or tensioner. They are different parts and not interchangeable.
Do Celcius CTW parts fit a Systema PTW?
Hop-up chambers and packings are cross-compatible across Systema PTW, Celcius CTW and G&D DTW, and retailers list them together. Tolerances do vary though, and some Celcius units run slightly short, so check your air seal and shim it if needed.
Does an A&K K4-STW use PTW packings?
Yes. A&K built the STW and K4-STW to the PTW pattern, which is why parts are cross-listed for PTW, CTW, STW and DTW together.
Why are the hop adjuster kits not on this page?
Kits that bundle an adjuster, roller packing and fit pin are chamber hardware rather than a standalone packing, so we keep them out of this list deliberately. The consumable rubber is what this page is for.
How many Systema PTW buckings does Airsoft Upgrades track?
We currently track 22 distinct Systema PTW hop-up buckings across 8 retailers, starting at $0.99. The Systema PTW and its relatives (Celcius CTW, G&D DTW, A&K STW / K4-STW) run a proprietary hop-up chamber that shares nothing with the standard AEG one. It also uses its own vocabulary: the rubber that grips the BB is the CHAMBER PACKING, not a bucking, and the part the hop adjuster presses onto it is the ROLLER PACKING rather than a nub. Searching for a bucking will not find the part you need.