223 -5.56 case difference

[Steve H]

I'm stumped.............

Here is what I have. 1000 Federal sized 223 cases, 1000 sized and primed 223 Remington cases. All of these cases are "good" in a Lyman case gauge.

I also have about 250 Privi 5.56 sized and primed cases almost all will not fully go into the Lyman case gauge without a little push then they seem to "pop" in. I have resized some of the Privi cases through three different dies, All RCBS, a FL die, A X die and a small base die without any improvement. Is there a difference in the rim that I might be missing that is causing this? The Privi brass stops about .020 bdfore it drops into the "ok" part of the case gauge.

 

[rcmodel]

Sounds likely.

Why don't you measure the rims and find out??

rc

 

[Steve H]

Why don't you measure the rims and find out??

Brain fart.......just did. Privi is about .008 bigger diameter

 

[FROGO207]

Dang metric ammo producers!! My PRIVI brass reloads still shoot fine in all my 223/5.56 firearms so no big thing there I feel. YMMV

 

[lysanderxiii]

What was the actual number? The case spec is 0.3780" -0.010" at the rim and 0.3759" - 0.005" at a point 0.200" from the base of the rim.

If the case rim has expanded larger than 0.3790", you may not want to reload it. Usually the maximum head expansion is 0.001" over what it started at.

If you have a head expansion of 0.008" over the above maximum, it might indicate a serious over pressure or a soft head.

 

[HexHead]

That's a manufacturer difference, not a caliber difference. There is no difference between .223 and 5.56 brass. The differences are the leade in the chamber of the barrel.

Use different brass.

 

[lysanderxiii]

There are minor tolerance differences. Compare the tolerances on the ARDEC drawing to the SAAMI specs.

 

[HexHead]

Let me know when you find some 5.56 reloading dies.

 

[steve4102]

Let me know when you find some 5.56 reloading dies.

LOL, good one.

 

[Steve H]

OK I just ran out to the shop and checked a sample of each type of brass

Privi 5.56 .379
LC 5.56 3.77
Federal .223 .373
Rem .223 .375
PMC .223 .375

Lyman case gauge .380

these measurements were a small sample, I want to think the other day when I checked more of the brass the Privi was .379 - .380 and the Federal was averaging around .373

the Privi is once fired through one of my guns

 

[steve4102]

The rims and case heads become slightly damaged when fired from semi-autos.

The number one reason for using the tubed type case gauges for Paper Weights and not for handloading.

 

[Walkalong]

Yep, I sometimes have to knock a burr off of a .223/5.56 rim to make it slip into the case gauge. If it hangs on the web, it needs to be scrapped, but if knocking off a burr on the rim lets it slip in it's good to go.

 

[steve4102]

Problem is many handloaders take this "failure" to enter the gauge as a sign that the shoulder is not set back far enough.

They screw the die further into the press more and more and the case will still not enter the gauge.

Then they bring their problem to their favorite handloading forum and the first and most common advice is to "purchase a Small Base die".

Two ways to solve this all to common problem.

http://www.sheridanengineering.com/index-2.htm

https://www.hornady.com/store/Lock-N-Load-Headspace-Kit-With-Body-1-Each/

 

[balderclev]

All of my 223 reloads are LC 556 brass. Never had a problem with any of them in several rifles after resizing. Don't have a gauge.

 

[steve4102]

All of my 223 reloads are LC 556 brass. Never had a problem with any of them in several rifles after resizing. Don't have a gauge.

Imagine that.
Odds are, if you had a tubed type gauge, you would be finding "problems" that really did not exist. The best way to eliminate sizing problems associated with a tubed type gauge is to, get rid of the gauge.

 

[Paddy]

What's a "tubed type gauge"?

 

[steve4102]

What's a "tubed type gauge"?

A chunk of metal with a hole. Cut to minimum spec, specs that are much smaller than actual chamber dimensions.

http://www.midwayusa.com/product/45...space-gage-223-remington?cm_vc=ProductFinding

 

[Walkalong]

Most chambers.

 

[higgite]

Actually, the Wilson gauge that Steve's link shows isn't cut to minimum chamber specs. It has an oversized ID to accept fired cases as well as resized ones. It is only intended to gauge headspace and case length.