300 Blackout Problems

[gunfan2]

I'm not sure that I am in the correct forum, someone please correct me if I'm not. I am loading some Missouri cast and coated bullets (subsonic loads) for my cz 527 in 300 Blackout. Load has been really promising shooting about moa at 50 yarks. Picked up my brass and noticed an unusual sort of thing. Right at the top of the little rounded shoulder I have about 3 cases show a very short lenier crack in the brass. If anyone has had this problem please let me know! This is blackout brass that was formed from 221 fireball brass. But I noticed a few Federal factory brass showing the same thing.

[CraigOK]

Can you anneal a test batch 5 or 10 and load up twice that many several times to see if that solves your problem?

[gunfan2]

I'm hoping this is not something to do with a chamber issue. The gun really shoots well, better than any with subsonic loads that I have owned. By the way the federal brass are factory blackout brass.

[Adam20]

i have the same gun, i shooting 130 grain cast subsonic with 4.3 unique.
reformed lc 556 brass, i get neck splits after about 6 or 8 reloads.
no anneling at all

[BK7saum]

Probably a brittle brass issue. Annealing the necks should solve your problem.

[Bull-Moose]

Split necks are a common issue with converted brass. Annealing can help extend the life of the brass. Once they crack, time to scrap them.

[gunfan2]

I suppose that making those from the 221 might have caused the necks to be extra thin. I have lots of 223 brass might trying making some from those. Does Remington brass form well? And do they have to be thinned in the neck area after forming?

[44Blam]

I converted 27 pieces of 223/556 brass and did all my initial testing with those cases. They were never annealed and I am shooting sub to just super sonic loads with alliant 2400.
These cases all have 4 reloads on them and they seem fine. I was going to keep them isolated to test how many reloads I can get out of them...

[BK7saum]

I ran converted R-P and LC 5.56 brass in my CZ 527 300 blackout without any issues. Cast bullets at .3095 and jacketed.

[gunfan2]

Thanks to all for the info given on this issue, I'm going to make some more from R-P 223 Brass and see if they'll do better than the 221 converted.

[44Blam]

One problem I had was some brass is thicker than other brass. So, I found that if the neck is thicker than about 0.012", it will not chamber in my rifle. So, I measure and separate the brass into "good neck" and "bad neck".

With the "bad neck" cases, I turn them so they are 0.0115" thick and they work perfectly.

[1006]

You might try only partially resizing the brass.

I shoot a Ruger American Ranch in 300BLK and have never had cracked or split brass. Normally, the area that wears out with full power supersonic loads is the primer pockets. My Sub Sonic bullets are very low pressure target rounds with a 150 grain bullet and 5 grains of Red Dot or Clays-these cases, seemingly, last forever.

I have only used factory 300 brass.

My reloading technique is to only partially Full Length resize with a Hornady Full Length die or to Neck Size with a Lee Collet Neck Size die. I do not bump the shoulder back. As a result, I have had a few that were tough to extract after firing-I have not figured out weather the Lee Collet die or the partial resize with a Full Length sizing die is the likely cause of sticky extraction.

[cwlongshot]

I suppose that making those from the 221 might have caused the necks to be extra thin. I have lots of 223 brass might trying making some from those. Does Remington brass form well? And do they have to be thinned in the neck area after forming?
Agreed 100%

Use 223/556 and anneal your problems should disappear. I feed six of these and honestly do not remember a cracked neck. Loose Fed brass primer pockets... Now get a coffee and we can talk!!

God Bless,

CW

[gunfan2]

Anyone have any pointers an on annealing process?

[BK7saum]

There should be a couple of threads dedicated to the process.

[gunfan2]

I don't doubt that but that screwey search engine that is here I can't seem to make it work. I used to get good results from that search engine, but it just all of sudden quit working, at least for me.

[gwpercle]

Cold working brass ...any and all brass ... causes it to "work harden" the hardened brass cracks .
The only to help the situation is to anneal the cases before they crack ... annealing softens the brass .
At some point in time the brass will wear out but annealing lengthens the time and it also helps when reforming one case into another .
Gary

[gwpercle]

I don't doubt that but that screwey search engine that is here I can't seem to make it work. I used to get good results from that search engine, but it just all of sudden quit working, at least for me.

New and improved search engine can't find Doodley - Squat ...
It's Dazed and Confused and Lost at Sea!
Gary

[BK7saum]

One of easiest ways to anneal is use an electric screwdriver with a medium/deep well sock that the case body will fit. IN A DIM LIGHTED ROOM, place the case neck/shoulder in the flame while being slowly turned in the electric screwdriver. As soon as the neck starts to glow faint orange, dump the case, either in water or on a damp towel to cool. Should take about 4 to 6 seconds to get the faint orange, depending on torch flame temp and position. IF YOU GET THE NECKS RED, YOU HEATED TOO LONG. Hence the annealing in a dimly lit or darkened room. I have never messed with tempilaq, this always worked for me. I now have a dedicated annealing machine, which I set up in a darkened room.