223 case sizing variation.

[AJC1]

So data can sometimes show you the truth and other times drive you insane. I measured every piece of 100 that I sized in preparation for bullets heading my way. My chamber is 1.460 when measured to datum. I sized cases that were range pickups and were all rp aka Remington. This is for a bolt rifle so my criteria was 1.460 or less. The kings portion of cases sized 1.4595. I don't believe the .0005 but it's a 5 or zero on the digital I was using. Another large group was 1.460 and 8 pieces were rejected because they were not sufficiently sized. I could use them due to camming action but I don't want to. I had 3 that were below by 5 thousandths and I believe they never fully fire formed. Unfiltered I saw about .010 variation, but I only loaded 1.460 and below. What type of variations do you see. I'm sure I'm fighting an uphill battle not annealing but I'm data collecting, and that will be in the tests after I get some unannealed results.

 

[Walkalong]

+/- .0015 with decent brass, half that with top notch brass, my Dasher cases all come out with a .001 spread.

 

[AJC1]

+/- .0015 with decent brass, half that with top notch brass, my Dasher cases all come out with a .001 spread.

This is match brass or bags of second hand brass bought on line. That level is about what I see in the br with lapua, but in a strange kinda way I'm proving why I buy good unfired brass. This is an exploration on the why, and I can speak from experience. Funny I have the good stuff and am doing this for experience, when the normal frustration is normally convincing people to buy good brass. I'm sharing this experience and making notes for the boy.

 

[koni]

And this is why I gave away my other brass and went to all lapua brass for my custom rifles. Hunting and plinking rifles they get what I can find..

 

[Engineer1911]

case length < 1.760" when full length resized, inside case mouth chamfered with counter sink, primer pocket crimp chamfered with countersink, brass is ready to load.

Reloading range brass is not that difficult.

 

[243winxb]

range pickups

You measured 100 I do 3, set die and forget it.

I do sort by case weight using LC mixed headstamp.

Testing is the only way to know what works. A reason to keep shooting.

 

[entropy]

case length < 1.760" when full length resized, inside case mouth chamfered with counter sink, primer pocket crimp chamfered with countersink, brass is ready to load.

Reloading range brass is not that difficult.

He's measuring at the Datum line, which indicates he's concerned about shoulder contact with the chamber wall. He wants as little as possible, or none. He's also trying to eliminate variables that can reduce accuracy, in a very determined manner.

I load for both a couple bolt .223's and several AR's, so I use small base dies, set the shoulder back 'just a titch' and do everything else as you mentioned, and I get accuracy that, while not in the realms of what he's attempting, is more than satisfactory for my needs. (under 1 moa out to 200 yards from the bolts, a little over that from the AR's)

 

[Charlie98]

I don't load for a bolt gun in 5.56mm, just AR's, and I do my sizing by batch... 1000 cases at a time.... on my RockChucker, and then trim them with my Giraud TriWay, which indexes off the shoulder. I get trimmed OAL all over the map. I'm sure it's tolerance stacking... first from sizing, then from the trimmer (which I've not mastered just yet,) but I really think the culprit is variances in brass hardness and springback during sizing.

 

[AJC1]

You measured 100 I do 3, set die and forget it.

I do sort by case weight using LC mixed headstamp. View attachment 1096842

Testing is the only way to know what works. A reason to keep shooting.

I measured them all to learn. Being of unknown origin the plan was to remove any case that would not size to maximum chamber size. Those I plan on annealing at some point and testing separately. I also plan to fire form. Uniform and weigh. Then I will take the extremes from both ends and volume test. I will maximize the learning and experience from this trial.

 

[AJC1]

He's measuring at the Datum line, which indicates he's concerned about shoulder contact with the chamber wall. He wants as little as possible, or none. He's also trying to eliminate variables that can reduce accuracy, in a very determined manner.

I load for both a couple bolt .223's and several AR's, so I use small base dies, set the shoulder back 'just a titch' and do everything else as you mentioned, and I get accuracy that, while not in the realms of what he's attempting, is more than satisfactory for my needs. (under 1 moa out to 200 yards from the bolts, a little over that from the AR's)

The current die set is a rcbs small base set. I prefer forester sizing dies but I will complete this run with the same dies.

 

[Charlie98]

Those I plan on annealing at some point and testing separately. I also plan to fire form. Uniform and weigh.

Ignorant question: Does fireforming really make a difference in a small cartridge like the .222 or .223?

 

[entropy]

I'm not seeing any .223 case dimensions of 1.46. What am I missing here?

The only dimension I care about using range brass is the trim length. I've heard of sorting by weight but I not interested in doing that. I just use LC brass exclusively. All range pick up.

That is the point at which brass should contact the shoulder, i.e. the proper headspace. Brass longer than that may not seat fully without 'assistance' , such as the camming of a bolt or the forward assist of an AR.

Ignorant question: Does fireforming really make a difference in a small cartridge like the .222 or .223?

My personal belief is that it doesn't, but I know some who do so, with .223 and .22-250.

 

[243winxb]

For longer brass life-

Some 5.56/223 brass brands, make it almost impossibe to pull the expander out of a sized/ lubed case neck, using standard dies.
A donut forms or is there from factory new brass.
Over working necks causes them to fail early.

Bushing die, Lee collet neck die or outside neck turning helps make longer brass life.

 

[AJC1]

Ignorant question: Does fireforming really make a difference in a small cartridge like the .222 or .223?

Taken from the package new and shot in a bolt returned to the box I would say that the size of the case would probably require tools I don't have to generate good significant data. In this case study it will make a huge difference based on some of the dents in the cases. I expect results much worse than a new bag based on mixed lots, abuse, and fired in different guns. That makes it interesting.

 

[AJC1]

For longer brass life-

Some 5.56/223 brass brands, make it almost impossibe to pull the expander out of a sized/ lubed case neck, using standard dies.
A donut forms or is there from factory new brass.
Over working necks causes them to fail early.

Bushing die, Lee collet neck die or outside neck turning helps make longer brass life.

View attachment 1096851

These are sized with expander ball removed and neck set by mandrel. It's the only process I use.

 

[jmorris]

He's measuring at the Datum line, which indicates he's concerned about shoulder contact with the chamber wall.

If that’s the goal this method doesn’t even use measuring tools. Turns the rifle itself into a “go-no go” gauge.

 

[AJC1]

If that’s the goal this method doesn’t even use measuring tools. Turns the rifle itself into a “go-no go” gauge.

I know the chamber size, and for the sake of tracking and logging datum measments for variation doesn't matter.

 

[koni]

The current die set is a rcbs small base set. I prefer forester sizing dies but I will complete this run with the same dies.

Doesn’t small base dies work the brass more by sizing all the way down to the web? I doubt that would make them grow in length that much, but with out annealing how much brass spring back is normal for small base dies? I don’t own any small base dies

 

[Engineer1911]

I'm going to need more butter and popcorn. This 9 shades of Special.

 

[Blue68f100]

Doesn’t small base dies work the brass more by sizing all the way down to the web? I doubt that would make them grow in length that much, but with out annealing how much brass spring back is normal for small base dies? I don’t own any small base dies

SB dies work the brass more by being smaller dia at the base. They don't work any lower than a regular set of dies.

 

[AJC1]

SB dies work the brass more by being smaller dia at the base. They don't work any lower than a regular set of dies.

I don't believe they provide benifit if your shooting a gun that doesn't need it, but when using range pickups gets you back to a minimum. Switching a die during a test program adds to unknowns I can't account for. It does work the brass more which would be a disadvantage, I counter that with it being a die in common use and in this test case will give results associated to dies in common use.

 

[BushMaster-15]

As all guns are NOT equal ,I use MY chambers to set Dies . 0.002" set back Bolt Rifle 0.004" for gas guns . As I prefer case expansion to a degree along with neck swell for sealing purposes ,so annealing is the trick .
Stiff Brits DON'T seal well but annealed brass is the ---- Azz . Hunting rounds are slightly more set back ,as fussy ammo has NO place on the field . I've never personally seen a measurable group spread form 0.000" or 0.004" set back ,same with off the lands . 0.012" or 0.040" jump . So many other variables to concern yourself with ,so it is what it is . Not saying it doesn't happen ,simply saying I've NOT seen it with regards to MY measuring .

 

[IALoder]

+/- .0015 with decent brass, half that with top notch brass, my Dasher cases all come out with a .001 spread.

This is pretty much what I've seen as well. Sometimes it varies ~.005" with range brass with different headstamps and probably fired from different rifles. But for blammo ammo, it works fine as long as it chambers!

 

[AJC1]

This is pretty much what I've seen as well. Sometimes it varies ~.005" with range brass with different headstamps and probably fired from different rifles. But for blammo ammo, it works fine as long as it chambers!

That's about my final variation after taking out the longs. I expect a firing or two will bring them a lot closer. The largest diviation is short so that will self correct.

 

[kmw1954]

I just finally broke down and purchased a comparator for my 223 loading.Should have done it long ago.

My Savage measures 1.462 with the Norma brass I have been using. So I set my sizing die to what I thought was 1.460" and started sizing and measuring each afterwards and sorting by length. This brass ran a range of 1.459 to 1.462 with 90% being between 1.4595 to 1.461.. So as 1.460 as my set point I am not going to quibble. And yes that is with my wrongly annealed brass.

Of the 140pcs I sized the other night there were 8 pcs that are going to be set aside to be loades as foulers as they were either shorter than 1.459 or longer than 1.462

I too was actually amazed at how accurate I was with just using the Lyman case headspace gauge. Because I checked those with the comparator before I loaded them last week. Still both have been a fun exercise and now I have reassured myself.[/QUOTE]