Article By Zack Sudler
I have had the good fortune to acquire an Adam’s Arms Carbine Length Piston kit. I can tell you it is a pleasure to shoot and has worked flawlessly thus far. It’s design is well thought out and well implemented. The overall concept is to keep hot, dirty gasses out of the receiver to increase reliability by preventing carbon buildup in the upper receiver.
Here is a breakout of what the system is comprised of…
There are several different components in the Piston Driven AR-15 System. All are beautifully machined and the finishing is well applied.
The bolt carrier is a solid piece of steel and is milled to perfection. There are no tool marks to be found on the exterior and only the smallest tool marks on the interior of the unit in non-critical areas. All edges have been radiused and the exterior finish is smooth and evenly applied. The Adams Arms logo is professionally applied to a recess in the carrier body and really pops. The bolt head, firing pin, cam pin etc are not included with the Piston System kit. (It would be nice to have the option of purchasing these parts – or a complete bolt assembly on the Adams Arms website).
The Gas Block and Gas Plug – are built to very exacting tolerances. The fit of the Gas Plug is perfect with no perceptible movement/slop whatsoever – but the plug slides in and out of the Gas Block like silk. This assembly is also beautifully machined with the same quality finishing as the Bolt Carrier. This part also has been laser etched with the Adams Arms branding and logo as well as the Serial Number for the Piston System. The patent number is also scribed onto this unit.
The Gas Block is secured to the barrel with two hex head screws and should be rock solid when torque appropriately onto the barrel. The Gas Plug is adjustable and removable for maintenance and cleaning via a retractable detent pin.
The adjustments allow for Normal operation, reduced gas intake for use with a suppressor and full lockout of the gas system to prevent the action from cycling at all. There are very clearly defined detents on the front of the Gas Block to secure the Gas Plug into the correct position. There is no chance of the Gas Plug moving into a different position without user manipulation.
When the Gas Plug is indexed to the 3 O’Clock position it easily slides out of the Gas Block for cleaning and maintenance.
This is a very efficient, user friendly design. Users should have no difficulty tuning the Gas Block/Gas Plug to their needs. Really well designed.
To add to the utility of the system Adams Arms has seen fit to mill a Picatinny rail onto the top of the Gas Block. This allows users to forward mount their BUIS or other rail attachments out front. This is a very nice feature.
The Gas Piston Drive Rod is very straightforward. It is made to perfection and fits perfectly onto the Gas Rod. The finish is like the rest of the Piston System – Perfect…
The last major component worth mentioning is the Modified M4 Style Hand Guard. These will look pretty familiar to anyone that has handled an AR15 rifle. They are made of high impact plastic and have an aluminum heat shield in the lower section of the hand guard. The hand guard assembly is modified to accommodate the Piston Drive Rod by enlarging clearance hole on where the gas tube would normally enter/exit the hand guard. The Hand Guard retaining ring has also been modified in a similar fashion to allow adequate clearance of the Piston Drive Rod. These hand guards are not fancy but they will do their job of protecting your hands, providing a good gripping surface and protecting the piston components within.
I would like to see Adams Arms add compatible milled aluminum forends that will work with the Piston System. This would help the customer make the correct product choice, should they choose to upgrade the forend hardware. (Adams Arms branded or other manufacturers) This would also provide a one stop shop for Adams Arms customers – with the correct product in hand and only one shipping fee.
The reason I say this – I purchased a DD rail system that I believed would work – it did not. (which DD fixed immediately with no up charge). I was pulling my hair out trying to get everything to fit – the rail system did not allow the piston rod to align properly – thus, it would not install. Drove me NUTZ… The replacement rail solved the issue immediately without any install problems.
My overall impressions of the piston system are hugely positive. The fit and finish are excellent. The system is well designed and user friendly. The installation is relatively straight forward and does not require any unusual tools and can be completed in roughly 1/2 hour.