Fired .223 brass drops right into Wison case gauge - good, bad, neutral?

[IMtheNRA]

Well, this was a surprise. I tumbled 50 pieces of Lapua twice-fired .223 brass and was about to reload it tonight. I dropped one piece into a Wilson .223 case gauge and I was surprised to see it go in with a metallic "thunk" of a re-sized case. I checked the rest and all 50 dropped right in, with the case head about 2/3 of the way between the minimum and maximum marks on the gauge. Here is the history of these 50 cases:

When new, I full-length re-sized these cases and ran them into a Giraud trimmer just to make sure. None were long enough to trim. I fired them once, then full-length resized them and trimmed/chamfered in the Giraud, reloaded, and fired again.

Rifle is a semi-auto AR rifle: JP CTR-02 with a Wylde chamber. Load is not hot, just a SMK-69gr averaging 2,740 fps. (21.2 grains of Viht-133)

So now I am wondering what, if any, is the significance of these fired cases fitting into a case gauge. Should I be happy that I don't have to FL resize them? Should I get a neck sizing die and leave the case body alone, thereby extending their useful life?

If I end up neck sizing only, then these cases will no longer be of uniform length, after getting a little short as a result of the last firing. Their range is 1.7435 to 1.7520, mostly on the shorter end of this range, so I can't trim them in the Giraud. Unless the neck sizer will stretch the necks. Will it?

My primary goal is making the most accurate and reliable ammo that I can for this particular rifle, and case life is of secondary importance. But, it would be nice to use Lapua cases over and over

What's your advice?

 

[cfullgraf]

Virtually all cases gauges for bottle neck cartridges measure only shoulder position and over all length of the case. They are cut generously in the diameter dimension of the body of the case. The gauges are not chamber gauges. Check the specifications, i.e. read the fine print, from the manufacturer

So, a fired case would most probably slip into the case gauge.

Hand gun case gauges are a different story.

 

[dmazur]

From the instructions that come with the Wilson gauge -

This is a one-piece non-adjustable, cylinder type gage for checking fired and resized cartridge cases for cone-to-head and over-all length. These gages are not made with chambering reamers but with special reamers giving extra clearance both in front of and behind the shoulder so as to elimi-nate any possibility of contact except at the gaging point.

While there is no guarantee that every fired case will fit, Wilson did make an effort to permit this. What you are describing does not sound unusual. Many use a Wilson gauge for measuring a fired case, then adjust their resizing die until the measured depth of a resized case is 0.002" greater (or whatever the desired bump is.)

Then there's this information -

Reloading for gas guns

which includes this cautionary note:

As basic as this may sound, a Service Rifle is not a Benchrest rifle. Both of them are extremely accurate, and both are used in their respective competitive venues. However, the requirements placed on the ammunition are quite different. Many of the techniques beneficial for a Benchrest rifle are of no value for a Service Rifle. Others may be counterproductive, and some can even be dangerous. Well-intentioned handloaders who fail to appreciate these differences face potentially serious problems and a lot of frustration. We encourage you to read and understand the differences involved.

"Neck sizing" and "gas gun" are generally not compatible, in other words.

 

[IMtheNRA]

Yes, you're both right, of course. According to the LE Wilson info sheet that I finally read as you typed your posts, , the gauge is cut to provide extra clearance both in front of and behind the shoulder in order to eliminate any possibility of contact except at the gaging point. Hmmmm...

 

[Slamfire]

Wilson case gages are fine if you understand that they measure length only. Shoulder to base length.

If you want to measure "fatness", then you need a chamber reamer cut gage. I had Frank White of Compass Lake Engineering to make me one for the .223 he was barreling. He used the same reamer that cut my rifle chamber, he cut the gage to proper depth. It cost me about $35.00. Been a while.

Here is a Wilson gage and a reamer cut gage in 308. Both of these fired cases are unsized and they are fat. However, as you can see, one drops all the way into the Wilson gage, the other won't drop in the reamer cut gage.

That is the difference.

 

[IMtheNRA]

Thank you, everyone, for the input. I did not realize there is such a difference between case gauges and chambers.

After doing some more reading on this topic, I see that my JP case gauge (Wylde chamber) is made with a chamber reamer. This explains my previous observation of some random fired cases (not those discussed above) fitting into the Wilson, but having their head-end a little too fat to fit into the JP gauge.

From JP web site:

Unlike other case gauges, ours is cut with an actual match chamber finish reamer so it not only checks head space but also case diameter. A common problem for reloaders with high-grade rifles with tight chambers is out-of-spec ammo that will not go into battery. If you have a high-grade barrel with a tight chamber, this is the only sure way of assuring that your ammo is compatible. Most gauges only check head space. Some also indicate minimum and maximum case length. Only the JP gauge checks min/max headspace, min/max case length and case diameter relative to typical match-grade chambers.

 

[fguffey]

"this is the only sure way of assuring that your ammo is compatible. Most gages only check head space. Some also indicate minimum and maximum case length. Only the JP gage checks min/max head space

This is the only sure way (they know) of assuring that your ammo is compatible.Most gages are believed to be able to check head space when in fact a gage referred to as being a head space gage is a go, no or beyond gage, A reloader can determine the length of the chamber from the bolt face to the shoulder of the chamber and the reloader can determine the length of the case from the head of the case to it's shoulder, problem! they do not know what to call the difference between the length of the case and the length of the chamber.


"Some also indicate minimum and maximum case length. Only the JP gage checks min/max head space" again, the Wilson case gage is not a head space gage, it measures the length of the case from the shoulder/datum to the head of the case, reloaders familiar with the manipulation of tools can use a steel rule/straight edge with a feeler gage to determine the length of the case (in thousandths), knowing the length of the case is from cute to nice to know if the reloader does not know the length of the chamber, and that is the reason all these tools being waved around as head space gages should be called comparators or length gages.


"....this is the only sure way of assuring....."

I do not agree.

F. Guffey

 

[chrome_austex]

You need to be full length resizing cartridges for autoloader rifles. You don't need much, but you do need to make them smaller. After full-length resizing they should fit in either the wilson or JP gauge. You can then dial back to the minimum amount of resize to fit that JP case gauge (or your actual rifle by measuring fire brass in your Wilson gauge).

A chamber gauge is useful to dial back your full length resize die, but they should be trusted to to match your actual chamber. Frankly I find the Wilson die to be more useful because I can throw a fire case in there and get a shoulder length measurement without it binding up on the diameter of the case.

You should see the brass that comes out of my Remington 700 308. Its so much bigger than a JP case gauge its not even funny. However if I full length resize those 308 rounds they will fit in a JP 308 case gauge. Luckily I can neck size for that gun because its a bolt rifle and I can feel if something doesn't fit right.