I was recently asked this question…
How do I avoid check ring leakage?
Many heated discussions have arisen as a result of check ring leakage, but the simple fact is: All check rings allow some plastic back-flow (leakage). There are specialized products on the market which try to eliminate check ring leakage, but they eventually cause excessive barrel wear… resulting in inconsistent leakage.
In most important factor with check ring performance is the consistency of check ring leakage. Inconsistent leakage can result in defects such as Flash, Short Shots, and Sinks. For this reason, it is important to routinely perform a dynamic check ring repeatability test to ensure proper performance.
For more about this test, please feel free to read: