260 Ackley Improved Freebore

[montanaearl]

I am building a 260AI, actually 6.5/08AI based on JGS reamer print. This print shgows 0.050" freebore which seems short for the longer bullets. Without loading up a bunch of dummies and measuring them, can anyone who has experience in building this chamber comment on the proper freebore to shoot bullets from the 123 scenar through 140 SMK's, A-Max's and A-Frames?

 

[mysticplayer]

You are right, it is short and set up to primarily for a 2.80" OAL to fit in a typical mag. Too short for the VLD 140's most will be using.

With my 6.5 Mystic,similar to what you are doing), I throated the chamber in a second step once I had my bullet OAL figured out. Because bullets ogive and lengths vary so much, I found this the best way to make sure my combo fit the way I wanted.

Otherwise, you would need a custom reamer cut using your loaded cartridge. I didn't see that cost as being worth while.

A throating reamer is like $25 and I use Dave Manson throaters.

Jerry

 

[montanaearl]

thanks. using a throater in a second pass after some experimentation with different bullets makes sense. i am intentionally using a long action platform so as not to be limited in bullet seating depth by magazine length.