300BlkTalk

Gotcha.......Thanks
Rog

I am also headed to the nut house, I realize this is an old thread and how I found it, just shows the degree of desperation I am in. I am hoping someone will notice a new reply and chime in. I am having the same problem with jams.... I think I have narrowed it down to neck size, thanks to my sheridan gauge, seems every round that won't fit is .335.....so my two questions are.....the bad brass list (which I pay close attention to in my sorting), wasn't every round on the bad list.... sold as new at one time....did they jam as new ?? I understand the case expands when fired....but I don't understand how the wall thickness enlarges ?? Do people just throw these bad rounds away after buying fired once mixed brass......surely they don't take the time to turn necks.....wouldn't you be better off just buying new brass? My second question is even if you start with brass on the good list and cram a cast /coated .310 bullet in the mouth....I don't seem to be able to stay under .334.....it expands the neck...I don't seem to have this sizing problem with FMJ's.
or even plated....I am lost. some of my procedures are sort , RCBS small base size,M die expand , Lee seater, Lee factory crimp
I have no trouble at all with straight wall cases or .223.....it's just a blackout thing

thanks in advance

The good/bad brass list only applies to .223/5.56 brass for conversion. It does NOT apply to factory 300 BLK brass which should be good to go.

As for cast, the only converted brass I've used is LC, which generally is .011 - .012 neck thickness. Never had a problem loading and shooting cast up to .311.

Are you starting with once-fired 300 BLK brass? If so, what headstamp(s)?

the bad brass was 223 or 5.56 .
after sizing to 300 you are down into thicker brass when forming the 300 neck.

willis.

oops, bang posted while i was replying.

Thanks bangbang & willis.....I get it now......this was just one of those things I could not figure out....your two answers makes it clear now
Thanks for taking the time, I was using converted once fired.....I knew to sort out the LC... but I'm sure a few of the others must have slipped in

Need to watch factory BO brass with cast too. Hornady and a few others have thick neck - made for jax.

Fighting this battle myself with a Seekins upper/lower and a Wilson bbl. My bbl seems to only reliably chamber .010-.011 thick necks. .012-.013+ are too thick. I wound up buying a hornady neck trimmer tool to get them consistent and thin but I still have the occasional load that needs to be loaded twice to go completely into battery. Initially I was using a caliper to measure but now have a tubing mic which is giving me accurate numbers. I will have to go over some of my first batch of trimmed brass to find the fat ones. Remember you are into the thick body of a 223 when you cut and form a 300, you have thicker brass but there’s also runout where one side is thicker than the other. The hornady tool eliminates this which should make for more accuracy. To me the whole draw of a 300 is using essentially scrap 223 brass available everywhere. If I’ve got to buy new virgin 300 brass to reload that I only find half a mags worth after firing I’ll have to part ways with it. I’ve trimmed and thinned another batch and will check these out this week. I don’t mind the extra reloading steps as I’m a tinkerer but I’ve got to get it to run.

Put 28 rds into my containment target and 65 yd steel. Everything chambered fine. Now I will build some more loads but my first try using 110 gr RN is grouping 1/2 in at 40 yds. It didn’t like my zmax loads though.

If you enjoy turning necks, or are doing it for accuracy that’s fine. If you are doing because you think it’s normal then there is no reason to.

Not sure if you have seen this thread at the top of the handloading section, it can help you choose thin brass I’d you don’t want to turn, or thick if you want to turn it to fit your chamber. Either way might save you some time.

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Kawa wrote: ↑Tue May 10, 2016 3:13 am Thank you folks for all of your in put and I appoligize for taking so long with my reply but I was waiting for delivery of my Sheridan Slotted Gauge (cute little guy) which I just recieved my I see what all of you were and just where the "Hang up" is. The problem with getting an answere is in most cases it creates another question.

QUESTION: Will clean, resized brass that drops into the Sheridan Gauge change its neck size when introduced to the bullet? I know I can just load up another and find the answer but I have so many rounds to disassemle I thought I would just ask.

To answer dellets' question.....NO! I never had a bullet pull loose from a stuck case.

I want to once again than you for all of your input......no matter how smart we think we are we're never smarter than all of us. Not sure who said that but it sounds like something John Wayne would have throwen out after a gun fight.

Thanks again,

Rog

300 BLK and 5.56mm NATO are an intermediate class rifle cartridge for target shooting, hunting, home defense, and plinking. ... 300 BLK has a wider range of projectile choices, thanks to the . 30 caliber bore, burns its full potential in a 9-inch barrel, and is a much better choice for hunting.