PDI claims that 6.05mm barrel is more accurate than 6.01mm inner bore barrels.
and also claims that 6.05mm gives the best balance between range/accuracy
To sub-quote PDI, here's what they said:
"6.01mm for velocity, 6.05mm for accuracy"
many people from arnies have vouched for this statement but hard facts has never come out yet.
it has not been proven with picture/grouping tests.
though there have been a test showing the performance difference between a PDI 6.01mm and Prometheus 6.03mm inner barrels in a Tokyo Marui Glock.
Prometheus had better groupings than PDI barrel.
http://www.arniesairsoft.co.uk/forum...owtopic=145725
DISCUSS