300 Blackout primer question

[dddoo7]

I am in the process of loading up some 300 Blackout rounds. They are going to be for a cva break over single shot. I am using once fired .223 brass, cutting it off, trimming, and die forming it for the blackout. My question is, I have several thousand small magnum pistol primers, but I don't have any small rifle primers. Will small magnum pistol primers work, or should I just wait until I can get some rifle primers. What is the difference in these two primers.

I am planning to use 220 smk's or 225 HPBT hornadys with AA1680 powder. I will start slightly high and work down to 1050ish fps.

 

[country888]

Re: 300 Blackout primer question

I would use small rifle. I use cci small rifle in mine. I would be afraid to try the pistol mags not knowing. I dont think you have to worry about pressure with subs, but why take a chance. But if your not getting enuff then you have a bullet stuck in your barrel. I would just get some small rifle and go at it, its a cheap fix judt to get primers that work. If you decide to try them though, keep us informed how they did. Good luck.

 

[BK7saum]

Re: 300 Blackout primer question

Use rifle primers. I still get high enough pressure is some sub loads to flatten and deform the primers. This is for the heavies. They are running significant pressures. Fir my lighter 110 sierra HP loads with Am Eel powder. The pressure is much lighter according to primers.

 

[dddoo7]

Re: 300 Blackout primer question

Thanks for the replies. I will wait until I get some rifle primers. I went to pick some up a few days ago, and they were out, but they should be back in stock soon. I do not have the barrel yet, so it is no big hurry.