Getting the .410 itch

[FL-Boss]

Thinking about building up a .410 since TSS loads are now available.  Want to start with this Mossberg 510 youth. I like the fact that this gun has a 18.5in barrel.. but also concerned it may be too short?
I would get the barrel threaded to take a tighter choke.

You think this would be ok out to 40 yards with TSS 9.5 and a better choke?

http://www.mossberg.com/product/510-youth-mini-super-bantam-all-purpose-field-50355/

[SumToy]

we are playing with the short stuff now.  I know in past the Moss has did good.  I did one at 28 then cut to 24 it picked up 20 shot in the 10.    We fixing to do one at 22, 23 and 24 to see.   

If you thread yours you should have a 40 yard gun with 9s.