[Yissnakk]

Hey guys and gals - I'm beginning to reload 300 Blackout from converted .223 cases and have learned that certain cases have a thicker wall just below the shoulder (on the .223/5.56 original) than others, which leads to difficulty in chambering when you, say, load a .309 or .310 cast/powder coated bullet vs a .308 jacketed. The SAAMI specs for the 300 BO indicate that the loaded neck be no wider than 0.334 and some of the case walls (Wolf and PPU, for instance) have case walls up to .015 but usually .013 which, times 2 = .026 + .308 gives me exactly 0.334; use a 0.309 or larger bullet and no go.

This brings me to the crux of my ramblings. Who, here, turns their case necks regularly in any scenario for precision reloading and if you do, what method do you use? I've seen some people who just clamp their brass in a drill and run it on a 1000 grit sanding pad for a few seconds, measure it out with a ball micrometer and repeat as needed until the desired thickness is achieved. Then there are these others, who are generally hawking something, that insist that you need to spend at least $100 on a good neck turning tool (Hornady is the cheapest stand-alone I could find that had anything close to good reviews).

The other option would be to just make sure I only use known good brass to make 300 blackout cases from.

I'm just seeking advice from all ye more experienced and knowledgeable than myself.

Thanks!
JJ

 

[Yissnakk]

I ordered 1K of converted brass from some dude and it is looking like about 2-5% of them are going to be "bad". I may just do the ol' drill and sand paper to test the theory on a few, but if I can't get them to work, I will just pull the few and toss the rest.

Thanks gents!

 

[Yissnakk]

Yeah, I ordered brass for expedience but will make my own from "approved" brass going forward. As a worst case, I'll just toss these "unapproved" cases into my brass recycling bin. I tend to find a lot of .223 brass at the local range, and can order it from SNS casting for $0.05/round with 95% being lake city.

Just need a harbor freight cutoff saw

 

[Yissnakk]

I recently reformed some .243 cases to .22-250 cases. I had to turn the necks, but that was because after reforming, trimming and annealing the new necks were the old shoulder material. The shoulder brass being thicker I had to turn off about 3 to 4 thousandths. You shouldn't need to turn yours though since you are shortening the cases and expanding the necks. Neck thickness should be about .013.

Therein lies the rub. I think I've found a way around the whole thing - just resize my bullets to .308 instead of .309. the SAAMI specs tell us that the neck of a 300 Blackout cartridge loaded needs to be 0.334 diameter. with a neck wall thickness of 0.013 and a bullet of .308, it comes out to just right (0.308+0.013+0.013). The Lakecity and FC brass has a neck (once a case wall) thickness of 0.011 on average, and brands like Wolf and PPU have a wall thickness of 0.013-0.015 which puts it a bit out of spec. As long as I'm shooting powder or hi-tek coated lead bullets, they remain malleable enough to chamber, but jacketed bullets using the wrong headstamp...not so much.