I've had hundreds of Notos pass through my shop and ive seen the Gen l guns had tighter barrels, they were also accurate but the bores lacked polish and often needed hand lapping to tighten them up.
The Gen ll guns lost the second drilled/tapped hole on top of the receiver but the barrels were a little better made and didn't foul as quickly.
The Gen lll (we are here now) Notos have very deep, tapered crowns, some 1/2" (12mm) or more. These barrels are even looser but pretty smooth.
The CPHP's you are shooting like more speed at distance, the 750fps they leave the barrel at is good for 30ish yards, they drop below 500fps by 50 yards and fall out of stable flight, giving you large groups.
The JTS, JSB, AEA 18.1gr pellets like the slower speed of the stock Notos but you are still at the very edge of its ability to pest past 30 yards when stock.
This does not mean you are out of luck! Simple modifications to the receiver and swapping out the air cylinder for a larger carbon fiber bottle will dramatically increase your shot count and pellet speed.
With the right barrel, porting and drip block, even 100 yards at just over 1 MOA is possible with the venerable CPHP!
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