Hi jake
As far as i'm aware the SX3 is also available in 3'' as well as 3.5 and should cycle 32 no 6's with no trouble at all.
I bought my SX3 Composite 3.5'' about a year ago and it has never let me down once. As mally has already stated , the 3.5 chambered version like mine does prefer the larger 70mm carts , but saying that , when i first got the gun i had a few 67mm carts left over from my previous o/u and the SX3 also cycled these with no problems at all. As for shooting , i still can't believe how little recoil is felt compared to other semi auto's that i have used , but i suppos