BJB UZI 3-Pack RECOIL~BUFFERS - Reduces recoil and muzzle climb. - Select rate of fire increase by using different buffer sizes. - Will fit semi & full-auto models.
This is an insert taken from Randy's Web site. This was a test that one of Randy's buddies did.
Randy sent me a complete set of buffers to test for ROF. The set consisted of buffers that were .50", .75", 1.00", 1.25", and 1.5" in thickness. We had found that using stacks of buffers caused binding and a change in ROF while you were shooting. So, Randy decided to make some solid buffers to see how they performed. I used Walmart Winchester 115 gr ammo and PMC 124 gr. Here are the results: 1.4" Buffer - 978 RPM (Winchester) - 817 RPM (PMC) 1.25" Buffer - 933 RPM (Winchester) - 791 RPM (PMC) 1.00" Buffer - 848 RPM (Winchester) - 708 RPM (PMC) .75" Buffer - 787 RPM (Winchester) - 590 RPM (PMC) .50" Buffer - 717 RPM (Winchester) - 579 RPM (PMC).
The ROF with both types of ammo using the original equipment thin buffer is about 565 - 570 RPM.
I also had some American Eagle 147 grain subsonic in truncated cone and gave that a try with the 1.4, 1.00, and the .75 inch buffers. That ammo apparently is pretty hot even though it is subsonic (heavier bullet keeps it subsonic). ROF for the American Eagle ammo was 999 RPM with the 1.4 inch buffer, 866 RPM with the 1.00 inch buffer, and 792 RPM with the .75 inch buffer.