June 9th, 2010
The Madbull Ultimate Hop-Up is a one piece M16/M4 style hop-up unit. What sets this hop-up apart from nearly every other on the market is its ring style adjustment system. Most other M4 hop-ups rely on a finicky and prone to unwinding 3 gear style adjustment system. The adjustment ring design reduces overall parts count, increases reliability and makes this hop-up a breeze to assemble. The other major innovations introduced by this unit are a BB retention o-ring and the ability to attach a “LED Tracer Unit” that is able to charge glow in the dark BBs as they pass through the hop-up unit. More on these later.
The Madbull Ultimate Hop-Up can commonly be found for $30 including a hop-up bucking, which makes it pretty competitive with most high quality M4 style hop-up units on the market. The body of the hop-up is made of a nice, shiny light alloy (aluminum or some sort of ‘pot metal’). The C-Clip, adjustment arm and adjustment knob are all precisely formed from a high quality polymer.
Included in the package are:
- The hop-up unit body
- Adjustment knob
- Adjustment arm
- Arm pin w/ retainer
- Hop-up tension spring
- Hop-up “C” locking clip
- Brass stabilizer tube
- Madbull blue bucking w/ rubber nub
- Adjustment knob retainer o-ring
- Gearbox seal o-ring
- BB retention o-ring
The instructions give a very simple 6 step assembly process (including installation of LED tracer unit). In any case, the parts provided are simple and few enough that one can assemble the unit without directions.
- Put on the three o-rings
- Put bucking on barrel then install in unit body, making sure that the barrel is properly aligned
- Push on hop-up “C” locking clip
- Slide stabilizer tube down barrel & nest inside unit body in front of locking clip
- Install the adjustment arm with nub, pin, and pin retainer
- Push on the adjustment knob while making sure that the adjustment arm fits into the knob’s groove
- Pop on the tension spring to the knob in front of the adjustment arm
The only difficulty I experienced when assembling my hop-up unit was with the Madbull blue bucking’s fitment. Madbull makes these buckings slightly thicker than normal so when trying to seat the bucking inside the hop-up unit, the bucking can stretch and may prevent the installation of the locking clip. If you encounter this, simply remove the bucking and trim 2 to 3 mm off the front of the bucking (the wide end, not the narrow one) with scissors or a knife.
The first gun I installed the hop-up in was my old G&P XM177E1. The hop-up fit into place nicely, and not too snugly to prevent the unit from sliding back and forth on its tension spring.
Unfortunately, when I tried to install this unit in my brand new G&P Sentry M4, I found that it was impossible to make it seat. As it turns out, Madbull has over-sized the ‘wings’ on the left and right side of the hop-up. The tops and bottoms of these wings must be filed down significantly to make the hop-up seat properly in some guns. See the pictures below.
Once completed, the hop-up slid easily into place in my Sentry.
Performance / Adjustment
Unfortunately, I have no quantitative data to share with you here. Nonetheless, I can confidently state that the hop-up is very consistent, much more-so than the original G&P hop-up units these guns sported. The hop-up is capable of very fine adjustment, although it is actually somewhat harder to reach the knob than one would imagine. This is especially the case in the Sentry where the faux bolt does not retract enough to fully expose the adjustment knob. In both guns I’m now running a Madbull Ultimate Hop-Up, Madbull Blue Bucking, Vanaras 6.03x300mm Tightbore Barrel and Element H or Fishbone hop nubs and I couldn’t be more pleased with the results, especially considering how little it all cost me.
Remember earlier when I mentioned that the hop-up has a BB retention o-ring? This o-ring is supposed to prevent BBs from leaving the hop-up chamber during mag changes. In my experience, the o-ring was minimally effective after just a little use. In the XM177E1, it fails to retain all the BBs and in the Sentry, the o-ring simply tore and fell out of the gun. The manual mentions some manual modifications that can be performed to tune this feature, but I haven’t cared enough to try them yet. Three to four BBs don’t matter much when you’re using 130 round midcaps.
The Madbull LED Tracer Unit that is designed to be installed on the Ultimate Hop-Up is used to charge tracer BBs as they are fed through the gun. The tracer unit has a MSRP of $40, which is fairly reasonable considering what most barrel mounted tracer units go for. While it is nice to have the flexibility, ultimately, tracers are a novelty and this feature of the Ultimate Hop-Up is unlikely to see much use.
The Ultimate hop-up is a great choice for anyone in need of a replacement hop-up and I certainly can’t complain about its performance. Hop-ups generally do a very simple and boring job and the best one can ask for is consistency and ease of adjustment. This unit definitely satisfies both of those requirements.
Consistent backspin application and precise, secure, adjustment are the best features of this product. While the BB retention system is an interesting idea, it is unreliable in practice.
Some filing of the unit may be necessary to ensure proper fit in some guns and the provision for a LED tracer unit is unlikely to be used by most players.
For $30 with a bucking and nub included, the hop-up is competitive with other units
Does this hop-up deserve the title “Ultimate”? Probably not, but it brings several very welcome features to the market.