Hi,
I have a brand new honey badger pistol. Unmodified, except that I swapped the rail for a lighter colored one.

The first ammunition I ordered for it were subsonic loads manufactured by Grace Ammo. This ammo had lake city headstamps (which I assume means it's modified 5.56 brass) and 200gr SMK bullets. Immediately I went out in the yard to test fire and on the fourth round I got a "click, no bang." But it wasn't a dud, the bolt carrier had not fully closed and had prevented the hammer from hitting the firing pin.

I went inside and started hand cycling the ammo. Every 9 out of 10 rounds (roughly) the bolt would not fully close on. And yes, I wasn't easing the bolt forward or anything like that, I was drawing the bolt all the way back (or locking it back) and dropping it. The bolt would stop with the carrier just about a centimeter from being fully closed. Worse still, the rounds were getting stuck. Really, really stuck. Most of the time, I would have to brace the pistol brace against my chest, and pull with both hands on the charging handle to get it loose.

Texting a friend, he suggested that the bullets were too long, (they were loaded "mag length" aka as long as you can load them and them still fit in a mag) and that the bullets themselves were getting caught on the rifling of the barrel. This made sense to me at the time, but when I went to his house and he seated the bullets a bit deeper, the same problems kept occurring.

While I was there, I hand cycled some of these Grace Ammo cartridges through his .300blk gun and they hand cycled smooth as butter.

So I bought another batch of ammo, this time "Stryker" brand supersonics from American Marksman. Also lake city brass, supposedly new manufacture, 147gr FMJs. Same exact problem, although not as bad as with the Grace Ammo. Most rounds would chamber, but would still take considerable force to extract by hand, and then the occasional round that wouldn't fully chamber and would take undue force to extract from the gun.

An interesting tidbit:

I noticed with all this hand cycling that if I hand cycled the same cartridges over and over, they would cycle easier each time. After hand cycling the same rounds 4-5 times they would chamber and extract with ease. And with live fire, they would actually fire and extract, most of the time. This makes me wonder if jamming the same cartridges into the chamber over and over again form fitted the brass to the chamber.

My current thought is that the chamber on my honey badger is cut tight. I need to buy more ammo to test but it's expensive as hell and I don't want to spend a bunch of money on different ammo types troubleshooting this gun if I just end up selling it anyways. Especially when the ammo I have that doesn't work in my gun, works fine in other guns. I know I should be hitting up Q's customer service first, but I'd really appreciate a brainstorm here, maybe some experts, that might have an idea of what's going on, so I'm not going into Q's CS blind.

Thank you very much if you bothered to read all this.

Clean it, then chuck up a chamber brush on a piece of cleaning rod in a drill motor. Run it for about 30 seconds, clean it and try again. Keep doing this until the issue goes away.

So I bought a case length headspace gauge and another ammo type. This time it’s factory new headstamped .300 brass. It sits perfectly flush with the Lyman gauge and hand cycles through the Honey Badger like butter.

The Stryker brand ammo (new manufacture, converted 5.56 LC brass) protrudes a little bit from the gauge. Some of them sit close to flush, some of them are outliers and stick pretty far out. The average round protrudes from the gauge about 0.5mm. This ammo is spotty in the Honey Badger, hand cycling it. It’s worth noting that this stuff hand cycles fine through other guns.

The Grace Ammo is atrocious. One round protruded 2.13mm from the gauge. They vary from just less than 1mm of protrusion to some being over 2. So it’s no wonder this stuff doesn’t work.

So now I’m left to wonder, clearly my honey badger has tight headspacing, but is it so tight it’s out of spec? I would prefer it be on the looser side so that it can cycle the Stryker brand and other lower quality ammos, like my friends’ guns can. I couldn’t find a GO gauge for .300BO in stock anywhere. I have a feeling Q is going to tell me it’s in spec and I just need to use better ammo.