Rifle is 16", 1 in 8 twist, 5.56 chamber. AR15 Style.

Reload stuff is 68 gr Hornady BTHP. IMR 8208 XBR. Win Brass. CCI #400 Primer.
OAL 2.250
50th Edition Lyman.

Started at 20 grains of 8208 and went up to 23.4. (I was told to stay 1/2 grain from the max, due to the closest load being 69 gr SMK)

20-21.5 was all over the place. So i went home and loaded 22, 22.5, 23. and 23.4. 5 of each load. Also shot Factory Fiocchi 62Gr .223.

22.5 was the closest with 2 bullets touching twice. Also the cleanest ejected case. My issue is all shots had a level of primer flattening; some more, some less. Most interesting is that the factory Fiocchi was the worst and even had ejectore swipes on the head.

I emailed Hornady to ask if they had any load data. Hopefully I will get an answer tomorrow.

So my questions are:
Why does every case has some level of flattened primers or is it normal?
How is it possible that factory loads were the most pressured? (Im going to pull some Fiocchis apart and weigh powder.)
Should I worry about something? If I should what and how do I check.

Post pictures; one man's flat primer is another man's good load.
Oh, weighing factor powder charges tells you nothing; they use blended, non canister powder for factory loads.

Sorry but how do i upload pictures?

Put them on photo bucket, copy the IMG link, and paste them here.

quote:

Originally posted by diegoojay:
Sorry but how do i upload pictures?

Posting pictures:

http://forums.accuratereloadin...0106691/m/5571053971

Got it! It was Direct link not IMG
thank you!

One hard neck.
My first thought would be low pressure and the case not sealing the chamber. But that wouldn't explain the FF. QL calls your loads from around 38000 to almost max

quote:

Originally posted by ramrod340:
One hard neck.
My first thought would be low pressure and the case not sealing the chamber. But that wouldn't explain the FF. QL calls your loads from around 38000 to almost max

By hard neck do you mean to tight a hold on the bullet or something different??

Should I try a different Powder or Bullet to see if I get the same results?

No I was talking about the one case with the split neck. Normally a split neck is hard brass that simply needs annealing.

You can have blow back along the brass if your load doesn't generate enough pressure to fully expand the brass to seal the cylinder.

Welcome by the way.

I didn't' see any sign of high pressure; take a better picture of the primers. I see low pressure and insufficient brass obturation.

quote:

brass obturation

Show off!!! Darn I had to go look that up.

Yep what dpcd said.

quote:

Originally posted by ramrod340:

quote:

brass obturation

Show off!!! Darn I had to go look that up.

Yep what dpcd said.

Usually, I hear the term "bullet obturation", and most often that is in the context of muzzleloaders. But I think DPCD is right (as he always is)...

Got it. Ill post up some better pictures tonight.

Oh, there are no split necks just a very deceiving soot.

quote:

Oh, there are no split necks just a very deceiving soot

I would have bet a serious on 23.4

Get an adjustable gas block and fine tune it. Or go to a faster burn rate powder. Burn rate chart The CCI #400 Primer i have are soft. The flow and flatten at mid-range pressure using IMR powders. Change to a magnum or Remington 7 1/2 primer. NEVER USE REM 6 1/2 PRIMERS IN 223.

Note that the Hornady 68 has more bearing surface than the Sierra 69. This means the Hornady may produce more pressure then the Sierra.

Mid-range load, Max load, over load

Those sooty cases ( apart from the one with a split neck) imply lower pressure, rather than high.

Your primers are flat but that's probably more to do with headspace in your rifle than pressure.

As an experiment just neck size a case or two and refire the best load, I bet the primers won't be so flattened.

Got it! Haven't had time to load or fire but hopefully soon!