Instead of weights, it has a tungsten powder. The weights have a tendency to bounce or jiggle or whatever word you want to put there. The powder doesn’t do this. Throw a baseball on the ground. It bounces. Now throw a hacky sack on the ground. It doesn’t bounce. Same concept.
http://www.spikestactical.com/z/index.php?main_page=product_info&cPath=104_97&products_id=201
http://vuurwapenblog.com/2009/12/22/oh-products/
Many AR-15 carbines (specifically, 14.5″ and 16″ carbine length ARs) have reciprocating assemblies that are simply too light. While a high rate of fire sounds cool on paper, in extreme cases, a weapon that is cycling too fast can outrun the magazine spring, which will immediately result in some sort of malfunction.
In addition, standard buffers have weights that move a short distance in order to ensure that the bolt goes into battery and stays there (in extreme conditions, the bolt can bounce back out of battery slightly) – they slam forward inside the buffer after it has returned to its “rest” position, much like a dead blow hammer.
However, this additional fore and aft movement can give the impression of greater recoil. What Spike’s did was to replace the cylindrical weights inside the buffer with heavy tungsten powder. The powder still provides that extra insurance against bolt bounce, if not more insurance against bolt bounce, while reducing felt recoil. I’ll go out on a limb and say that according to my informal, unscientific observations, the ST-T2 buffer provides an amount of recoil reduction that might challenge some small muzzle brakes.
The best way to describe the way it shoots is that it just feels tighter.
Rated - Go to Magpul’s website and read their return policy. If it’s used and abused and you don’t like it, they take it back.
If for any reason you are not completely satisfied with your purchase we have a 60-day return policy on all Magpul products to allow the user sufficient time to field test the gear in the environment of their choosing.
If a newly purchased piece of Magpul gear is unsatisfactory, send it back for a full refund. If you would like to exchange for another item in the same price class we will gladly do so, however in either case, return and/or redelivery shipping costs are the customers’ responsibility.
Primary Arms has the best price I’ve seen on the DOA.
http://www.primaryarms.com/product.sc?productId=190&categoryId=42
They have the tritium Troy for $164 
