Finally got an answer to my question (difference between AA S410 & S510)

And the answer is -Not a damn thing. I found out that AA got so many requests for a high powered version of the S410 with side lever cocking.they just decided to rename this option the S510.

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Well AA most certainly missed their mark. The AA S510 is far from high-powered at 38 fpe in .25 caliber.

Compared to sub 12 fpe, it's high powered. They were mainly 22 cal and they are 33 - 34 fpe. 
 
Originally the "S410" was the SHROUDED AA400/410 model with bolt action. 

AA was the 1st mass marketed shrouded rifle widely available in the U.S. with it's 16mm shroud ( sill looks like a barrel ) that worked better than the maraiuder's and certainly better than their current 20mm model could ever hope for.

The S410 also had the better trigger w/no safety.



John
 
And the answer is -Not a damn thing. I found out that AA got so many requests for a high powered version of the S410 with side lever cocking.they just decided to rename this option the S510.

~~~~~~~~~

Well AA most certainly missed their mark. The AA S510 is far from high-powered at 38 fpe in .25 caliber.

The new regulated version is 43 fpe from the factory and can probably be tuned over that.


 
Originally the "S410" was the SHROUDED AA400/410 model with bolt action. 

AA was the 1st mass marketed shrouded rifle widely available in the U.S. with it's 16mm shroud ( sill looks like a barrel ) that worked better than the maraiuder's and certainly better than their current 20mm model could ever hope for.

The S410 also had the better trigger w/no safety.



John

Mine must be a later model! Maybe just before they went to s510 because mine has the dial power adjuster and the safety in the trigger. Full 16mm shroud with a factory moderator. Super quiet !!!

James from Michigan,