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one of the main misconceptions of the AI rounds and other improvements is that you can gain alot of velocity with less pressure, this is just not right, rocky is right about 2% gain at the same pressures with the same length barrel is the norm.
now most custom barrels are normaly a bit faster than a production one with the same loads due to the barrel being smother, and more consistant. you'll normaly see about a 100-125 fps increase with a custom barrel/min spec chamber over a production one.
Now you take a case and improve it, take out most body taper, put a 40 degree shoulder on it and polish the chamber to a mirror finish. So now you have brass that fits the chamber exactly, doesn't adhere to the chamber before pressures peak, and a min taper case not pushing back against the boltface like a backwards wedge. So you won't see your typical pressure signs, like ejector pin marks or heavy bolt lift until your pressures are way beyond what they normaly run in the parent case. so unless you have pressure testing equipment you have no idea what pressure your running in your AI chamber but must assume if your running greater than 2% increase in MV that you are running higher pressures. is this safe? not for me to say, but I know its not good for case life.
I have custom wildcats which show no pressure signs at all till the primer pocket won't hold a primer. So I experiment till I'm satisfied with the performance and case life and thats my max load.
RR
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