Waldo Dynamics - Crimson GBB Hop-Up Bucking - 70 Degree

After over a year of trials; the new bucking meta is finally ready

A Quick Breakdown

• GBB/VSR spec bucking
• 70 degree hardness NBR rubber
• Over-chambering prevention design
• Pronounced two-point of contact pressure patch
• Alignment fin

65 or 70 Degree?

The 65 degree Crimson is the all-rounder for BB weights between 0.28g and 0.40g, and suits the widest range of GBBs. The 70 degree is the choice for heavy BBs, roughly 0.30g to 0.45g and up, or for rifles with very heavy or steel bolts: the harder rubber resists over-chambering even more. Both give great results.

The Story

In collaboration with BBA (Bristol Based Airsoft) and Cheffington (Ian from Firesupport UK), Waldo Dynamics spent over a year trying countless bucking prototypes, materials and contact patch shapes. It started with an idea: what if the bucking had a tighter initial wall to slow the BB down, so it sits at the same point on the contact patch every time?

The Problem

A big issue for a lot of GBBRs is over-chambering: the BB is pushed inconsistently, slightly past the optimal point of the contact patch, as the GBB cycles. The weight and speed of the cycling mass is a lot to put on a 6mm BB and a rubber sleeve.

How It Is Solved

The Crimson bucking has a thick, durable initial opening. It takes considerable pressure to press the BB into the hop-up rubber, which stops the bolt and nozzle pushing it too far past the contact points.

The Benefits

A far more consistent flight path, so your shots go where you expect rather than drifting left, right, up or down. The two-point contact patch, with a valley in the middle, centres the BB while applying more than enough pressure for even the heaviest BBs. It is made from NBR, which is far more durable than silicone and will not tear during installation.

Waldo Dynamics have tested the Crimson GBB bucking in a wide range of platforms, including:

• VFC AR/M4 variants (including the EVO series)
• VFC AK, MP5, G36, G3, M249, PPSH and MP7
• VFC G-Series pistols
• Tokyo Marui GBB pistols (G17, Hi-Capa, USP and more)
• Tokyo Marui MWS M4 variants
• APFG MCX/MPX and XM7
• GHK M4/416 variants
• Vipertech M4 (with Meach hop-up chambers)
• Maruyama ISO-556

*Results will vary with the GBB used, recoiling mass, recoil spring strength, BB weight, ambient temperature, FPS/joule targets and gas pressure.