follow up...switched the radial barrel and bolt to the competition gun...clocked the Miculek comp... with the greatly lightened bolt and carrier.... Enidine hydraulic rifle length buffer... and comp there is very little dot movement...... now the problem is my vision.. the heat and allergies has really played hell with my right eye, and am not seeing a single dot in the Venom... will give it a shake down at the August match in Ruskin next Sunday...I found that I was inserting the magazines too high with the bolt open, and had clearance with them pulled down to the catch shelf... regards