Diagnosis of Chambering Issue 277 Fury to 6.5 Creed

[Leaf Litter]

I spun a 6.5 Creedmoor Mcgowen barrel onto my Tikka T3 action a while back and started reloading with Lapua brass with little issue, although my sizing die didn't seem to change the base to neck dimensions after the first couple firings. I did run into signs of a seemingly tight chamber in the form of reloads that were somewhat hard to chamber after full length sizing, as far as I can crank my die down.

My issue started when I tried necking down 277 fury brass to 6.5 creedmoor. Others had done so with no issue after trimming to length. I trimmed, full length sized, double checked my length dimensions, and everything seemed ok. However, the hybrid brass cases wouldn't chamber, not even close.

I suspect my chamber is exceptionally tight (short head spacing), and that was hidden by the use of Lapua brass that was significantly shorter than spec, as is common with raw brass. So what do you guys think, tight chamber, or something im overlooking trying to size these 277 fire cases down to 6.5 creedmoor?

Cheers!

 

[waspocrew]

What’s the neck diameter of a loaded round? Necks of the brass might be on the thick side. Another member mentioned needing to turn brass when converting fury brass to 6.5 CM.