Discussed at: [url]http://www.ccfa.com/counterp.htm
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The system works via 3 basic modifications:
1) Adding weight to the carrier.
2) Increasing recoil spring force.
3) Reducing buffer spring recoil force.
4) Increasing extractor spring force.

Also mentioned is Sullivan's work on an auto-regulating gas tube.

Thoughts?

I bought the Counterpoise system about 2 years ago. Installed it in my Bushmaster Car-16. The gas port modification was done by GG&G,(Bushmaster heavy barrel) when the were installing my front flip sight. The counter weight in the boltcarrier and the buffer and buffer spring replacements were an easy 3min installation. The D-fender(extractor ring) install took about a minute more.
The system works on the premise of slowing the felt recoil spike and making the rifle more controllable during rapid/automatic fire. I chose the system after speaking to Mack Gwinn at length about the Counterpoise and benefits to its usage. I found that when combined with the Knight's vertical front grip it is even more effective.
The upper receiver I had it installed on has recently reached the 800rd mark with no malfunctions, and the accuracy is still fantastic. I am logging each round and will post when it reaches the 2000rd mark (a true test of durability).
As for the regulated gas tube I got one later also from Mack , but since the Knight's Rail was installed already I never got a chance to use it. The homepage of both items is WWW.ARMFORTE.COM.


JerrY
Edited to fix spelling.