I am new to rifles and recently got my first rifle. I am very nooby. I recently bought a new Windham 300 blackout Rifle, I added a adjustable gas block to it. I have very very little time to shoot , so I shot 3 rounds of Sub sonic Federal rounds , I got my gas block working easily and after I found a stable setting on the gas block I gave it a extra half turn boost and tested it with another 3 rounds. Worked great. So like 6 rounds total.

Then I get some new ammo , some super Sonic rounds from Gorilla ammo "Pig killer". The ammo had a warning saying the primer isn't their usual material and it would be harder to make it go bang ,so use a modern rifle. I go to test it out , hoping the gas block would still be able to handle this ammo without adjustments. I fired about 5 shots , seems to be going well but then it stops firing. It was windy and sandy , I figured it got jammed with sand? I take out just the charging handle and ...I don't know what to call it but it's the parts that are for hitting the primer right? I do a quick cleaning and removed a decent amount of sand that coated the insides. I try to go shooting again to test it out but it won't strike the primer at all... I think it's still sand or something...I then realized I made a stupid mistake , I never checked the barrel. Sure enough a bullet was stuck inside without its casing. I got really lucky it was a shallow squib. So I pushed the squib out from the front end ( the long ways).

So I'm not 100 percent sure what can cause a squib , a few google results seem to only blame the ammo and that it should be 1-100,000 chance to happen. But I only fired 6 rounds. Was my luck that bad? Or was it because of my gas block even tho it DID fire 5 of the same rounds before the squib. Could the sand somehow have cause the squib? Was it because of the new hard primers they used? Or was it just a poorly made ammo? Did they get cheap on the gun powder since supplies like primer ran out? Lastly my main question , should I fear that I will keep getting squib loads from the tub of ammo (180 rounds) it came from like a bad batch or a possible recall ? I'm so new to the platform and my rifle setup has very low recoil imo so I'm not confident I will notice a sudden lack of recoil, get another squib and then my rifle blows up. Ya I admit I'm scared of firing this Gorilla ammo now. Federal seems fine. Am I over reacting?