AR15 Complete Upper Receiver Piston designs
9We get phone calls from customers maybe 1 out of every 500 we sell that ask us things that we thought were obvious to them when they purchased an upper receiver from us, but it didn’t click with them. The reason your LWRC upper receiver came with a buffer spring is because YOU NEED to replace the buffer spring when you go from a direct impingement design to a short stroke upper receiver. The same thing happened we sold the Smith & Wesson 5.45×39 upper receivers and the LWRC M6AK uppers. All of the 5.45×39 uppers we have sold so far came with a new hammer spring because you need more energy to strike the primers on the 5.45×39 ammo that most people were shooting.
We have been a parts dealer for LWRC for a long time now and still very big fans of their product line especially after taking a tour of the manufacturing facility. In the last 2yrs we have to say the Adams Arms company has done a very good job of getting a durable piston design that is different than LWRC but seems to be well received. All of the Adams Arms Uppers we sell are complete upper receivers and their 5.45×39 uppers have been the most hunted upper receiver in the last year. If you look at the cost of the 5.45×39 ammunition in comparison to the 5.56 in cost, there is a big difference and you’ll get the money back on the upper receiver you purchased in just a couple thousand rounds.