Recentlly bought 2 rifles in 6.5 Grendel a CZ 527 and a Howa mini action. Both had feeding problems from the get go the CZ's bolt wouldn't pick up a round from the magazine,the Howa would feed 4 rounds 5th one would stick in the mag. So sent the CZ back they adjusted the extractor replaced the mag catch works fine now.
The Howa is another story mags are made of plastic and are hit or miss as far as reliability goes. So I returned the faulty mag to Howa and just waiting for the replacement,in the interim I bought 2 mags they work fine. Now I'm not an engineer but looking at the spring for the mag looked a bit wimpy Howa is useing a very thin wire.
E mailed them and suggested trying a bit thicker wire, different material for the wire or a combo of both. Still waiting for the new mag. Other than that both rifles shoot better than I expected.