This all came about because I had purchased a MBAssociates Gyrojet and found it suffered from poor accuracy. I soon was on a quest to find out why because the accuracy should theoretically be excellent. It did not take long to trace the primary accuracy problem to the ammunition itself. With varied consumer reports ranging from comments about it’s “drive nails” superb accuracy to common later reports of 10" - 12" groups at as close as 25 yards, a close inspection of the ammunition was in order. From reports the early ammunition immediately appeared to be more accurate than the later production. My first suspect was a misshaped or damaged jet orifice and although I did find some damage on a small amount of ammunition I was able to obtaining the ensuing test two problems became evident. There was a small “venturiplate” that was crimped into the rear of the projectile. This “venturiplate” houses the ignition primer and four tiny venturi or jets for the propulsion gasses. The “venturiplate” was off square on a small sample but by far the primary problem appears to have been that the roll crimp that holds the “venturiplate” in position would upon occasion actually cover part of one of the venturi. With a rear thrust this redirection of the exhaust from any cause would result in a SPIRAL flight path, thus an explanation for the 12" groups. In my test this condition appears much more often in the later “wadcutter” design than in the earlier “pointed” design ammunition. Unfortunately the high cost of what is now very collectible ammunition (current prices around $20.00 to $50.00 per round) and its scarcity makes further research impractical.