.300 Blackout

Been building a few rifles lately, just basic AR15's Built a 5.56/.223 M4 (top), and another 6.8SPC carbine build (bottom).


The current project is a .300 Blackout, mainly to run suppressed. The barrel arrives Thursday, but the cool thing about this caliber is that you can make your own brass from .223/5.56 brass. Here is a vid of a guy who made a jig that attached to a cheap saw from Harbor Freight and how he forms his own brass.



Saw a few things I liked, and didn't like, and proceeded to build a repeatable jig that just cuts brass.

Added a piece of UHMW for the end block for a definite measurement on each case.


Screwed the jig board to the base of the saw AFTER squaring it to the blade. A bit of trial and error but I got it done.


Made a few more for my buddies with .300 BO's, including a "witness case" to align the saw.


I omitted the "shoulder drop hole" from my design, as it caused a few jams in my trial tests. Went for 15 minutes and was able to produce 318 cut off cases, all the same length, give or take .003". The best part is that after the initial trim, no further trimming is needed.

We hope to do this a thousand times or so tomorrow.

Nice.... Are you planning on heavyweight 180 - 220 grain .30 cal. things at slow speed or sum ting lighter?

Andy, if you did not have such a good job and were not so old....I would hire you as an machinist apprentice in heartbeat. I know you are good at math, and have vision. I could teach you every thing I know.....it should only take a day and a half.

Mid weights first, for plinking. 150gr FMJ's. I also plan on cast 180+gr bullets with gas checks for subsonic blaster ammo. The rifle will primarily be suppressed. If/when I can find some 200gr SMK's and other decent .30 cal pills I'll play with those as well. I'll get some 110's when I can for high speed work.

I have high and low range powders at the moment, but I am trying to find some powder suitable for mid range work. That is the chore. Got a metric ass ton of primers, so that isn't a worry.

Had my 16 year old help me today.


We made 1,000 BO cases from a combination of FC and LC brass. FC for subs and LC for supers. That way we can keep the two separate. He was a good apprentice.



Sorry about the blurry photos. I learned all I know about photography from Redhook. If you want to trade knowledge for knowledge, my part shouldn't take more than a beer or two.

I have a couple of .30 cal. bullet moulds, hundreds of gas checks, and the lube/sizer dies just collecting dust here. They are yours if you want them.

Hmmmmm... You drive a hard bargain.

Know anyone that wants to buy .45 rounds?

Not sure I can post, only 41 post on this signature?

I have 1000

It isn't even a full round, only 9/20th of a round.

I did just get a new bullet mold for some .300 BO 230gr hard cast bullets. Cheap subsonics!