300 BO subsonic reloads

[ckcollins2003]

After reading this article, I still come away without a clear reason to use magnum primers in 300 blackout. The amount of powder (especially in subs) hardly requires a magnum primer. I understand that the load data calls for it, and that may be reason enough to use it I suppose.

It's not the primers. I use small pistol primers in my 300 BLK sub loads. It's most likely the bullets. I've had the same issues with the Hoosier bullets going into my chamber. I've had to mortar the rifle to get them to eject. Once ejected, I fed them through a friends SOLGW and it fed just fine. Tight chamber? Possibly... What upper are you running?

 

[rb288]

You said you were using "Top Brass" brass that is "reloadable" out of the bag.
Do you resize them before you reload them?
They are once fired and contrary to what they say, they should be re-sized prior to reloading just to be sure.
My "guess" is that the brass you are having issues with are just out of spec, headspace, just enough to cause no firing pin strikes.
Your case gauge should show that.
Re-size every case, no matter if it says "ready to use" or not.

 

[BAgun]

It's not the primers. I use small pistol primers in my 300 BLK sub loads. It's most likely the bullets. I've had the same issues with the Hoosier bullets going into my chamber. I've had to mortar the rifle to get them to eject. Once ejected, I fed them through a friends SOLGW and it fed just fine. Tight chamber? Possibly... What upper are you running?

It's an Anderson upper

 

[Elcidaviator]

It's an Anderson upper

Do you have multiple ARs? If so swap the firing pin or BCG and see if that fixes it. I had a firing pin that got warn down and no longer would fire the gun reliably. However, it would leave the brass dimpled. Probably not the fox, but one more check to rule things out.

 

[ckcollins2003]

It's an Anderson upper

Is the problem that they aren't going fully into battery and getting stuck? You definitely have to process your brass regardless of whether or not it says it is ready to load, but I've had quite a few issues with Hoosier bullets.