Any LC headstamp for 300 blk?

[cheese1566]

Been researching forming and making cases from 223/5.56 cases to 300blackout.

The consensus seems to use LC head stamps , which is great as I have few thousand. While sorting them, I see quite a few various markings other than the typical "LC 99" (LC and two date numbers...) Some have the NATO star, and other markings with the LC and two numbers.

is there a specific date number or marking to look for, or just run with them?

(I don't have a tubing micrometer to measure.)

[GRUMPA]

I can go through the whole process of explanation but I've done it to many times over the years. LC brass is the same, no matter what year it has stamped on it. Another thing is FC brass acts the same since those are made on the same machines.

[cheese1566]

Simple enough!

Thanks Grumpa!

[popper]

All made in Independance?

[No Blue]

Been researching forming and making cases from 223/5.56 cases to 300blackout.

The consensus seems to use LC head stamps , which is great as I have few thousand. While sorting them, I see quite a few various markings other than the typical "LC 99" (LC and two date numbers...) Some have the NATO star, and other markings with the LC and two numbers.

is there a specific date number or marking to look for, or just run with them?

(I don't have a tubing micrometer to measure.)

Dial calipers will get you within a ten thousandths or so. Just stick the jaws an eighth into the case mouth, that is the part of the jaws that are really thin. I did it, then took the same case and slightly flattened it and measured it again, so no curvature to span. Measured to the same number. You'll have more error from how hard you're leaning on the adjustment wheel than the curvature....I'm a tool junkie, but I couldn't justify the $40+ for a real tube mic, so I tried the dial calipers and it worked.

[WJP]

Seems I got most consistent sub accuracy with cut lc brass. Nothing though was real impressive. I quit using 1680 powder because I was getting better groups with h110. You loading for a semi or bolt gun?

[cheese1566]

At this time it will be a AR with a 16" barrel and pistol length gas system.
Long term project will be a Form 1 suppressor build and potentially shortening the barrel and permantly attaching the suppressor.

I have my name on the NOE Inventory Run of the plain base 311-247 FN Whisper mold.

This mainly a project to keep my mind and hands busy and a gun range plinker. Not intending to be a 100yd sub-MOA or hunting gun.

[WJP]

Mine kept me busy a while too. Fun plinkers it's just the fliers that keep getting me. I finally gave up for a while on it. I ran them across a cronograph and would get spreads of 80+ fps. Not fun when your trying to keep it right at subsonic. Finally got down to around 25 fps spread with h110 and called it quits. Same brass, weighed bullets, hand weighed charges. May have to drag it out again and play a bit. Hodgdon lists tb at 4.9 with a 110. I run a little less and they are extremely quiet suppressed.

[Shiloh]

I use FC brass when forming 8x57. Thats the only thing I use FC for. FC=8x57 brass.

Shiloh

[jsn]

The 300BLKTALK web site has a sticky/list of brass that will have thinner case walls, and hence make good 300BLK brass for a chamber with a standard .334" neck. LC's are generally good. They don't differentiate between Nato and non-Nato on LC's.

There is a note on FC's that they are not all consistant according to some user remarks, some look like they came from contract manufacturers or at least different dies. Some have thicker case walls and thinner webs.

Find a good lot of same mfg.'er brass, sample several. Chop off to your desired length, deburr and chamfer the new mouth, then measure thickness in what will be the new neck. Size and make some dummy rounds with no powder/primer and test for function in your gun. Then test loaded rounds at the range.

This free advice comes from a person who once got 900 free LC 08 7.62 brass, and prepped the whole lot only to find that none of them would hold a primer.

Sample, test, confirm, then go into production. It takes more time at the outset, but gets a god result. That's what I would recommend.

[Texas by God]

I know a guy that will trade finished .300 bo brass 1 for 2 5.56 brass. He prefers LC headstamps. Says they are more consistent. Keeps me from making my own! Best, Thomas.