If you are looking for a high-quality A2 buffer for your rifle-length AR15, consider Aero Precision's rifle-length buffer. This high-quality buffer is made to military standards and is specifically designed for A2 and A4 style rifles with fixed buttstocks. Remember: a buffer designed for rifle-length buffer tube is not compatible with carbines with collapsible buttstock buffer tubes.
When a bullet has been fired, the released energy causes the bolt carrier to travel backwards until it reaches the buffer housed within the buffer spring. At this point, the buffer will drive the spring backwards, compressing it against the buffer tube. As the spring returns to its extended position, the buffer will push the bolt and return it to the firing position, chambering a new round.
The weight of the buffer and the strength of the spring are key to ensuring the proper function of your rifle. A spring that fits securely within the buttstock of your rifle is probably the proper length. Buffer weights are a little trickier to determine. If the weight is too heavy, the force of the rifle firing will not be sufficient to drive the spring back and reload the weapon. If the buffer is too light, the bolt carrier will move too quickly and will be unable to perform its proper functions.
Buffer weights are dependent on the type of firearm you are operating. Carbine buffers weigh an average of 3.0 ounces. They include three steel weights. Heavy buffers (H buffers) have an average weight of 3.8 ounces. They consist of one tungsten weight and two steel weights. H2 buffers weigh an average of 4.7 ounces. They include two tungsten and one steel weight. The heaviest buffers of all are the H3 buffers. They have an average weight of 5.6 ounces and include three tungsten weights. One other type of buffer is the rifle length buffer, averaging 5.0 ounces. This buffer contains five steel weights with one steel spacer. The weights listed here are all approximations.
The actual weight of the buffer will depend on the manufacturer's standards. A buffer and spring that are properly matched will significantly reduce recoil while maintaining the momentum needed to successfully reload the weapon.