Chuck,
If I understand it, sounds like chamber is now 3" with a 3" forcing cone beyond. I don't doubt this reduces shot damage, particularly with the 3" shells that invariably (?) employ 1/2oz shotcups. I have to wonder if you have created, in effect, a proximal choke section with extremely long parallel section? Did you take bore diam measurements at beginning and end of forcing cone section? Just curious.
Wish I could bring myself to play around with a M-42, but don't have the cajones. If I find a beater M-37A I might just play with it.
3" .410 loads are odd ducks - through my barrels they behave as though there are two distinct populations of pellets. The "bad" population peels off early in flight. But the "good" population carries about as well as a good load from a 12. Let's say you have a full barrel. Using RP 3" #6 shells as an example, at just 20 yds you may see a pattern percentage of 65-70%. That's awful for a full choke, right? Moreover, it will have an impossibly small, hot core and few pellets in the outer circle. But move the paper to 40 yds and you just might see 65% again, this time the pattern looks useable out to 21" or so. Not so awful. I will say this - whoever said choke makes no difference with a .410 never shot any 40 yd patterns with one.
Sam
Last edited by Samuel_Hoggson; 08/02/10 11:26 AM.
