Fireforming .223 brass for my chamber with pistol powder and maybe filler?

CZ93X62

Official forum enigma
0.6 MOA is pretty darn good. Just sayin'.

There is no "nice" way to say this......but the 223 Rem is NOT an 800 yard cartridge, in spite of the M16A2's rear sight wheel's insistence that 800 meters is a reasonable expectation. Even the javelin hurlers with the 80-90 grain target missiles start calling a halt at about 600 meters. 800 meters is stretching things for the 308 Winchester, if you're being honest about the prospect. I don't mean to spoil your fun, I'm just trying to save you some frustration.
 

BHuij

Active Member
if it were me I'd invest in some LaPua brass.
why?
because even after all the whittling and massaging 90 sum percent of the others will still have striations in the case and other little uneven spots that will make them not the same.
you can weigh them, which will show that you weighed them but not where the weight is.

the key is to have an even thickness to the case walls [all the way up to the case mouth] equal thickness to the web area, along with square bases.
LaPua has that.

Yeah, this is probably where I'll end up in the long term. Saw some Lapua brass for about $0.60/case yesterday and almost pulled the trigger, but I want to see what I can get with the brass I already have first.

I did weight sort a whole bunch yesterday and got 50 cases that are matching Lake City headstamp, and all within 0.4 grains of each other. I didn't sort by year on the headstamp, but when I checked after I had picked my 50, I found that nearly all of them were 2012 headstamped. I'm sure it's not the same as Lapua brass, but it's the closest I can get without spending money right now :)
 

BHuij

Active Member
There is no "nice" way to say this......but the 223 Rem is NOT an 800 yard cartridge, in spite of the M16A2's rear sight wheel's insistence that 800 meters is a reasonable expectation.

Oh I'm aware that by 800 yards, the projectile will hit with all the force of a gentle breeze. But the ballistic calculators and chronograph measurements I have say I can get a 68gr match bullet to 800 without going transonic. In fact, at my elevation on a reasonably warm day, I should be able to get a 75gr match bullet out to 1000 yards before it dips below supersonic velocity. I've gotten my 68s to 600 without much difficulty so far, but started seeing a lot of vertical stringing as a result of velocity variations. A big part of all this hassle with my brass is about getting more uniform muzzle velocity. I think annealing in particular to get less variation in neck tension will make a noticeable difference.

As long as it will ding steel or punch a hole in paper, that's fine. I'm not worried about terminal ballistics with this rifle, at least not with non-expanding match bullets at super long ranges.

Maybe you'll be right, and my real world experience when I start stretching the legs on this rifle won't match the ballistic calculator. But I don't see any reason not to try.

Even the javelin hurlers with the 80-90 grain target missiles start calling a halt at about 600 meters.

Not the ones I know. I have personally gotten hits with my cousin's .223 AI rifle at 1080 yards. The new shoulder angle and increased case capacity that comes from it gives you about an extra 100 fps at the muzzle over standard .223. This was with an 88gr ELD-M bullet. Based on his muzzle velocity through the chrono (~2800) and the same ballistic calculator I've been using, bullet was still doing about 1500 FPS by the time it impacted the steel at 1080 yards.

Edit: Your comment about the 800 yard tick mark on the M16A2's rear wheel made me laugh. Reminds me of my Mosin with rear sights adjustable to 1000 meters. At that range, my Mosin might be accurate enough to hit a target the size of the Red October. Maybe.
 
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Ian

Notorious member
How does your .6 MOA rifle do at 800 yards now? Are you tilting at windmills?
 

BHuij

Active Member
How does your .6 MOA rifle do at 800 yards now? Are you tilting at windmills?
Biggest problem is vertical stringing. If I can fix that, I have no reason to believe it won’t do fine at 800 yards. I’ll be sure to report back when I’ve given it a try.
 

fiver

Well-Known Member
that would indicate ignition/velocity variations.
try bumping the load, or involving a slower powder that fills the case as close to 100% as possible.

I can see how your thinking annealing might help, but so can hardening after annealing, the key is finding the right amount for the brass alloy your using.
I know with cast,, annealing, then fire forming then working the neck over a ball sizer then squish sizing to get the tension I wanted was one of the keys to things coming together.
I kind of ended up with a good load, a throw away load, then a good load again doing it that way.
but the difference between the 'good' and the 'throw away' was some over 1/2".
 

Ian

Notorious member
ARs buck too, especially when shot prone from a bipod, which can cause vertical stringing.
 

BHuij

Active Member
that would indicate ignition/velocity variations.
try bumping the load, or involving a slower powder that fills the case as close to 100% as possible.

I can see how your thinking annealing might help, but so can hardening after annealing, the key is finding the right amount for the brass alloy your using.
I know with cast,, annealing, then fire forming then working the neck over a ball sizer then squish sizing to get the tension I wanted was one of the keys to things coming together.
I kind of ended up with a good load, a throw away load, then a good load again doing it that way.
but the difference between the 'good' and the 'throw away' was some over 1/2".
Yeah I suspect a slower powder would help. I’m in the highest velocity node I could find before running into pressure signs, so I stopped there. Could probably get more uniform ignition with a stick powder like Varget. TAC is kind of an AR powder, but it’s what I had and nothing else is available in the foreseeable future.

Hopefully annealing will at least put all the brass on the same starting point. I bought it as “once fired” brass, but that doesn’t mean once fired from the same rifle. Figuring out ideal neck tension is all part of the process.
 

popper

Well-Known Member
Problem with the tiny bullets and stability is mass. Fast twist overspins them ( to get tumbling on impact) but also to get rotational momentum/inertia up I=m*v. Muzzle fps gets forward I up but the spin is to get rotational I up so that imbalances (wind, etc) don't cause a change in trajectory. Point of force changes the 'balance' point also. May need to try the ELD version. Stability is NOT just dependent on length. Heavier bullets and slower twist (reduces axial force on bullet - target bullets have thinner shell) 'buck' wind better. 223 just limits what can be done.
 

BHuij

Active Member
Went ahead and ran 50 cases through the rifle. Used Lee 55gr .224" bullets with a gas check, powder coated, then sized to .224". Loaded over 8.5 grains of AA#2, seated out just long enough to get a slight jam fit into the lands so that the brass would be consistently held back against the bolt face when fired. Everything went as expected. Accuracy was bad, but that was kinda beside the point. No real fouling in the bore. Cases didn't show signs of pressure except perhaps very slightly flattened primers on some cases. These are WSR primers, so notoriously soft cups. Most importantly, nothing blew up and I had no misfires or hangfires as I worried with such low case fill.

I took the cases home, deprimed without any sizing using the Lee universal decapping die, and measured base to shoulder datum using the Hornady comparator and the A330 bushing. I had measured a random sample of 10 cases before I loaded them, with the following results:
  • 1.4565" average
  • 0.0065" extreme spread
  • 0.0022" standard deviation
  • 50% of base-to-shoulder measurements within 1 SD, 100% within 2 SD
After firing, I took another random sample of 10 cases of the same 50 and got these results:
  • 1.4595" average
  • 0.0040" extreme spread
  • 0.0015" standard deviation
  • 70% of measurements within 1 SD, 100% within 2 SD
So obvious conclusions: The cases are ~3 thousandths longer after firing, and a little bit more consistent with each other.

Here's what I'm not sure of: is an ES of 4 thousandths here fairly normal, or is it a decent indication that I didn't have enough pressure to effectively/fully fireform to chamber dimensions? SD of 1 and a half thousandths with 70% of cases within that distance from the average is pretty good I think, but the ES seems high. This comparator is new for me, but I would estimate that my measurement error here is probably no more than about half a thousandth on any given case.

If these figures seem more or less like "yep, those fireformed as you would expect," then I'll resize, bumping the shoulders back so they land at about 1.458", then anneal and load for accuracy with my heavier match bullets and proper rifle powder.

If they seem inconsistent enough to indicate they didn't fireform properly, then I suppose I could try again, maybe with a hair stiffer load (9.1 or 9.2gr of AA#2 instead of 8.5). The quickload data provided earlier in this thread indicated my pressure was around 37k here, and would hit 45k at 9.5 grains. With margins of error using imperfect simulated pressure data, I don't know that I'd want to push much closer to a "max" load of pistol powder.
 

fiver

Well-Known Member
with the pressure you developed, that's all your getting.
depending on the alloy I use [case brand] it could easily take 2 full pressure 'goin huntin' type loads to fire form them to my Ackley chambers.
the problem an AR has is it's trying to jerk the cases out of the chamber while part of the case is still trying to hang on.
you get a fire form alright, but it isn't always a good representation of the chamber walls.