45 LC Contender Reamed out for 410?

[kywoodwrkr]

Was cleaning some Contender barrels this weekend and found that a 45 LC barrel I had was reamed out to accept 410 shells-I assume.
Any experience with this home created 45/410?
I know TC had a factory setup like that but this is home brewed I'm pretty sure.
Anyone have chamber length required for a fired 3" 410?
Thanks.

[iron mule]

hey KYWOODWRKR the length of the 3" 410 chamber should be 3 " with a forcing cone added there is not a specific measurement for the forcing cones some are short and some are long some in between /// if you have access to a 410 chamber gauge that would be a quick way to check the chamber on the barrel hope this will help/// not sure of the measurement of the diam
mule

[deltaenterprizes]

Chamber needs to be slightly longer than 3'' to allow for the aprox 1/4'' length increase in length when the crimp opens upon firing.

[stubshaft]

Was the rifling reamed out also?