I just got some 5.5 mm fmj's with the hit inserts in them. Do I need to get the BAR 5 adapter for the arrows?
I have found that it depends on the broadhead that you are shooting. I have the Easton axis arrows and used them when i shot NAP Thunderheads but when i shot Rage I dont have too.
You should use the BAR or a flanged VPA collar regardless of the head. It's cheap insurance to protect the front of the shaft from a solid impact.
Most people just use them with broadheads, honestly it really doesn't matter so long as you match the field point up so its the same size as the BAR then it's makes for easy removal from bag targets .
I have tried Easton BARs a few times and could never get my BH to spin true. If anything I would use NAP UBAR (Universal Broadhead Adapter Ring). It fits all shafts and is metal not plastic like the Eastons. FWIW I have used Axis and FMJ for many years and never needed one. Unless your BH uses the arrow shaft to support the opening of the blade (blades prying/pushing on shaft) I would go without.
I've been shooting Easton Axis for several years and Beman MFX (both use HIT inserts) before them. Since I shoot good fixed blade BH's, I have never used the BAR system or footing of the shaft and likewise never had an issue with damage to the front of my shafts. One thing I have noticed is that some do not install their HIT inserts properly and need the BAR to avoid an air gap with a fully seated point. Axis will be in my quiver again this fall......without the BAR and ready to put down some more whitetails.