Some companies have made it their own policy not to ship rifle mags over 10rds to HI. Even though others sent them the HRS and proof that they're legal and by also sending in the rifle mag bills. Why ban something that is already illegal is the thought. Some replies are that the mag shippers said their attorneys disagree, others state internal policy.
There are still online shops that will ship to HI. For me, I rather support LGS. That would be if I owned any firearms, ammo, mags, reloading supplies, comms, body armor, preps.