The item was supplied directly from Deepfire HK. I spoke with Benjamin who was the sales manager. He was very helpful and after a bit of talking agreed to supply this item for review. I knew very little about Deepfire, further more I didn’t know they did some very high quality AEG M4 variants. I hope in the future I might be able to bring you reviews of these items as well.
The item was sent in a plain envelope and just had the retail packaging wrapped in the thick parcel covering. The item arrived in perfect condition although the envelope took a good bashing in the transit.
The item was shipped Airmail and arrived within approximately 5 working days (7 days if you include the weekend).
Upon opening the package, I was half expecting to find a broken piston due to how it was packaged. To my amazement though, the piston was in good condition. The Piston weighs a lot less than I would have thought for having full metal teeth. Upon looking at the piston, I noticed that the metal rack does not match the plastic teeth on the side of the piston. The 1st four teeth match and then the remaining 10 plastic teeth are out of sync of the metal teeth. This should not matter as the metal teeth are where the contact to the sector gear happens, but it might just cause some jams so I will have to watch out for this and check it out when I service the rifle again. I also noticed that the metal rack is not moulded into the piston, but rather it slides into place, the piston head holds the rack in place. This is good so that if the rack wears out and the piston is still in good condition, you can easily replace this.
The piston compared to a Tokyo Marui piston is as follows:
TM has all plastic teeth except the final tooth and is of constructed hard plastic, The TM piston usually comes with the spring attached to the piston via the weight block/nut for the piston head. In most cases you can hold the piston and unscrew the head off the piston. If you cannot you need to either cut the piston apart (I would advise against this as you then have a spare piston to fall back on if anything goes wrong) or you buy a new piston head.
Deepfire has full steel teeth with a titanium coating for durability and the body is of nylon fibre construction. I would advise using a Plastic/POM piston head over a metal one as this will cause less wear on the cylinder head if your piston head is Plastic (most are as standard). If you’re after quietness, there are a range of silent cylinder and piston heads that can be used in Version 2 and 3 gearboxes.
I installed the piston into my AGM M14 sniper rifle DMR using my original setup and was getting only 200-250 fps. I traced this down to the piston head I had transferred over from my TM piston. The screw in the middle was not allowing me to get good compression. However after 100 shots at 200-250 fps (still using the spring that previously gave me 350fps) there was no sign at all of wear, just some grease on the piston from the sector gear.
I will be carrying out an upgrade to higher FPS levels in the near future with a few more upgrade parts I have but I’m waiting on getting a piston head as I have yet to decide which one to go for.
Installing the piston into the rifle is fairly easy. If you’re fitting it to a Version II or III gearbox then it is really simple, Version 2 gearboxes are the easier of the 2 to work on. Version 3 has a tricky trigger arrangement that as long as you’re patient and very careful, you can reassemble without too much hassle.
The gearbox I’m installing the piston into is a Version 7 hybrid made by AGM. It’s by far one of the easiest gearboxes to work on, just accessing it though, that is what takes the time.
I will be doing strip down and upgrade guides of Version 2, 3 and 7 gearboxes shortly and putting them in my technical upgrade section.
I would suggest that when you install the piston head, you loctite the screw in place so that under the continued use, the piston head does not come loose and cause the gearbox to jam up. Vented piston heads are by far the better to use as well as they help improve the seal of the o-ring onto the cylinder wall and reduces suck back as well.
The improvements over the standard TM piston are that the metal teeth give the piston a lot more durability for high torque setups. There is less chance for the pistons teeth to strip when under load. The construction of the piston is of better materials than the standard TM pistons so should be able to resist a lot more abuse. From my initial tests, this is proving to be the case
Once I had fitted the piston with the upgrades mentioned below I fired approximately another 100 shots through the rifle on single shot (rifle is limited to single only) and then I opened the gearbox back up and there seemed like no wear on the piston rails or the teeth.
I will regularly service this rifle as its at such a high FPS compared to my standard AEGs of 350fps and if I see any wear or signs of failure I will update accordingly.
Currently the rifle already has the following upgrades installed:
- King Arms 7mm Bearings (gearbox professionally milled out)
- SystemA Area 1000 cylinder and cylinder head
- Guarder Tappet plate
- Guarder M120 spring
- Tokyo Marui piston and none vented piston head
- Guarder Steel cut off lever
- Deepfire Aluminium Piston Head
I will be hopefully installing this piston along with a new spring, gears and motor to get the FPS up to a more DMR level of 450 – 500fps.
The upgrades that I will be fitting to the rifle along with the Piston are:
- SHS High Torque gears
- SHS High Torque motor
- SHS Spring
- Vanaras 6.03mm 500mm long Barrel
- Element 65 degree Hard hop Rubber
I’m hoping for a steady FPS of 450 – 500fps with this setup. I will mainly be using this as a semi auto sniper rifle over a DMR due to the added range I hope to get from this set up.
The price of this piston in the UK averages about £30, a SystemA piston without metal teeth averages about £10. I still prefer a piston with full metal teeth on high torque setups as they can withstand more use. If you’re intending on high speed setups, Polycarbonate pistons are more suited for this job as they are lighter. The Metal teeth how ever do compensate for this and allow for the piston to be used in high speed setups. Just make sure you have perfect angle of engagement and if signs of wear on the 1st couple of teeth are visible, remove the 1st tooth to allow for easier engagement of the piston at higher speeds.
The piston is fantastic in construction and in the test fires since the piston has been installed have not shown up any flaws with this piston. I will continue to use this DMR M14 in games and as soon as I have the upgrades fitted I will add the revised review and if at any point the piston fails I will update this accordingly.
Value for money: 5/10
Ease of installation with fully assembled rifle: 3/10
Ease of installation with gearbox out of rifle: 9/10
I would only advise you take apart your AEG if you are competent with how the rifles work. Any guides I have mentioned about that my site has are for reference only and cannot be held responsible if you make a error in stripping or rebuilding your rifle.
I installed a SHS M130, M140 and M150 spring into this rifle. The M130 and M140 didn’t do any damage to the piston but when I installed the M150 spring, it took 5 shots and then the rear tooth snapped off the piston.
I have since installed an ICS piston into the rifle and that has withstood the M150 spring perfectly.
This makes this piston not good for high FPS setups as I was hoping.