I have wanted to do this test for quite some time now. The dome shaped vent liner sold by Lehigh has a 0.032" flash hole. It seemed the flat head vent liner should also have a 0.032" flash hole for a fair test, so one of them home made vent liner had to be used for a hundred or so shots before it also had a 0.032" flash hole. The home made vent liner start out with a 0.028" flash hole, so had to be shot to grow the flash hole to 0.032".











The V2 Accura was used for this test because the QRBP is so easy to remove, and replace. The test was done by installing the Lehigh vent liner in the QRBP, installing the QRBP in the rifle, and then loading the rifle with 270g Deep Curl, 100g BH209, smooth green Harvester sabot, and STS primer. The clock was located at 11 yard, and the target was about 100 yard out.

The load was fired, then the vent liner was changed to the flat head liner, and the rifle loaded, and fired. Then the vent liner was changed to the Lehigh liner, and the rifle loaded, and fired, then the vent liner was changed to the flat vent liner.......................... This was done for 10 shots each alternated vent liner. Shooting was steady until the wind blew the target stand down. Shooting stopped whilst i walked out to 100 yard, stood the target up, and walked back. Then shooting was steady until the wind blew the clock down. Shooting stopped whilst the clock was stood up. The barrel wasn't intentionally allowed to cool, but it never did get what i would call hot. Temperature was about 40 degrees at the start, and increased to about 50 degrees, and strong winds. The domed Lehigh liner was used to punch the top target.










.......1817 fps............ average of last 8 shot..........1813 fps






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