[Ventrib]

Also, extended chokes put the maximum hoop stress (where the choke will swell) outside of the barrel. Important if you're shooting hot mag loads, steel, etc. Extended designs also allow larger OD's to counter these stresses.

I bought a used A303 years ago and I found that the Moble choke (factory flush) was swelled in the barrel. Took several hours (and ruined a ct wrench) but it came out. Barrel was fine thankfully. PO no doubt shot something beyond Moble's design limit.