What size aluminum for footing Beeman ICS 400?

[Turkhunter]

I have done a search and havent found what size aluminum shaft needs to be used for footing an ICS 400. Thanks in advance for the help.

[Razorbak]

If I remember that would be a 2216 or 2117 for a 5/16" diameter shaft but if it was for the Axis or Bemans than a 2018 would work

[Dan Adair]

Good thing I have a gun hobby and used to be a machinist.

I mic'd a 400 MFX at around .4716"  All I had without inserts was 2020s and they mic'd .471" ID.  So given that the 2nd half the number is wall thickness, then theoretically, a 2018 would be about perfect.  I have access to an arrow saw, and stacks of junk 2018's.  PM me if you need some.

[Guru]

I've been footing ICS 400"s for a few years now....2117's are perfect!

[Kentucky Jeff]

How long do you all make your footings?

[Guru]

1"

[lpcjon2]

In the "How to" section is a chart

http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=2;t=000132