[kb58]

I bought a Wilson cartridge headspace gauge to measure some 9mm reloads.

1. First off (couldn't find it on the Wilson site) I'm assuming that the gage dimensions are set at the high (large) end of the acceptable cartidge size.

2. Therefore, if a cartridge fits the above gage, it means that it is some unknown amount below the maximum-allowable cartridge size.

3. If I take that same cartridge and drop it in a given pistol barrel, and it does NOT fit, #2 and #3 would seem to indicate that the chamber of that barrel is undersized. Does this sound right?

[1KPerDay]

Where exactly does it not fit? What bullets are you using? Some 9mm chambers have a short leade into the rifling and need bullets seated deeper.

[Walkalong]

Midway has an explanation. I assume it came from Wislon.

http://www.midwayusa.com/product/888465/le-wilson-max-cartridge-gage-9mm-luger?productNumber=888465

I use one because I have an EMP with a SAMMI minimum chamber. All my other nines will accept almost any sized 9MM case, but not the EMP.

[rcmodel]

Does this sound right? No.

It can simply be the bullet is seated too long, and is hitting the rifling leade.

The case gage can't tell you that.
Only your chamber in your gun can tell you that.

Take the barrel out of the gun and use it as the gage for setting OAL.

rc

[higgite]

I bought a Wilson cartridge headspace gauge to measure some 9mm reloads.

I don't believe Wilson makes a headspace gauge for pistol calibers. It sounds like you have their max pistol gage. The max pistol gage only addresses maximum dimensions. From the max pistol gage instruction sheet:

The WILSON PISTOL (CARTRIDGE) GAGE is designed to check loaded pistol cartridges for several maximum dimensions to ensure chambering in the pistol. It checks overall cartridge length, bullet diameter, case body diameter and length, rim diameter and thickness. If any of these dimensions are over maximum, the car- tridge may not function properly in the pistol. The gage will not indicate whether any of these dimensions are too small for proper functioning.

Go here http://www.lewilson.com/pistolmaxgage.html and click on the link for the instruction sheet.

[Walkalong]

Using an auto pistol barrel find a MAX O.A.L with your bullet.

http://www.thehighroad.org/showthread.php?t=506678

[kb58]

For a bit of background, these rounds are from a commercial reloader and while most fit, some don't.

Both of you are correct... it is the "Wilson Pistol Max Gage." Regarding max overall length, since it is one of the parameters it measures, and because none of my "bad" rounds have the tip of the bullet extending past the bottom of the gage. Because of this:

It checks overall cartridge length, bullet diameter, case body diameter and length, rim diameter and thickness.

This means they aren't too long, right?

Some numbers:
1. Rounds measure 0.378 at the top of the brass (bullet-end), 0.390" at the base (above the narrow "wasteline"), and 0.388 at the base.
2. The rounds are ordinary round-nose.
3. 1.152" OAL.

I just want to determine which dimension is wrong, or whether it's the chamber that's manufactured below spec. I rather not post the name of the pistol since it doesn't matter and will just start a brand war... learned that the hard way already.

I did test all rounds with the pistol barrel, and those that failed were tried in the gage block, where they all passed... hence my puzzlement.

[Walkalong]

The gauge does not check cartridge OAL, only case length.

[kb58]

Per Wilson's product description it does
It checks overall cartridge length, bullet diameter, case body diameter and length, rim diameter and thickness.

Checking to be sure, I just measured my test gage at 1.169" long. Per the figure below, the max spec for a 9mm cartridge is 29.69 mm, or 1.1689, so it's exactly at the limit. Since all my bad rounds fit, OAL doesn't appear to be the problem. The puzzle continues.

http://upload.wikimedia.org/wikipedia/commons/thumb/4/41/9x19mm_Parabellum.svg/400px-9x19mm_Parabellum.svg.png

[243winxb]

Glock bulge @ the web? See chamber drawing > http://www.saami.org/PubResources/CC_Drawings/Pistol/9mm%20Luger%20-%209mm%20Luger%20+P.pdf

[kb58]

I've heard that term before; where on the case is that point? Also, if that were true, wouldn't it cause the round to not fit in the gage? (The pistol is not a Glock, though I suppose the roloaded rounds may have come out of one...)

[243winxb]

1. Rounds measure 0.378 at the top of the brass (bullet-end), 0.390" at the base (above the narrow "wasteline"), and 0.388 at the base.
It would seem the .390" might be the problem. Yes, if ammo fits the gauge, it should fit the barrel. If the bulge is at the bullets base of the loaded round, the bullet may have been seated crooked.

[Otto]

What gun are you using...does it have a match chamber? Some guns are tighter that others.
Try coloring your cartridge with a permanent marker and then carefully chamber it.
Extract it and observe where the ink has rubbed off.

[kb58]

Yes it's probably a match type barrel. I had no idea that a manufacturer would purposely made a barrel tighter than spec. If so, it means that customers are left to find ammo that's made under-spec in order to fit. Huh.

[rcmodel]

Since all my bad rounds fit, OAL doesn't appear to be the problem.OAL has nothing to do with anything if you are using a different bullet shape then the FMJ-RN shown in the drawing.

A bullet with a different ogive can be hitting the rifling leade in your barrel and be fine in the Wilson gage.

Use the barrel out of the gun, color a sticky one with a magic marker, and see what is tight where in your barrel.

rc

[kb58]

I can see why every round must be tested in the actual pistol barrel, and that a pistol "max gage" cannot be trusted. It doesn't matter what a gage says if the ammo doesn't fit the barrel.

However, it bothers me that a precision max gage is useless, not because it is inaccurate, but because a pistol manufacturer tightened their barrel so much in search of accuracy, that it causes some - in-spec -ammo to not fit.

Guess that's what I get for looking for accuracy, and it's troubling. I mean, consider the man-fantasy of SHTF, where after months of searching you finally locate a box of ammo for your pistol, only to discover that your super-accurate match pistol won't accept the within-spec ammunition. I'm going to have to reconsider just how much accuracy I really need...

[1KPerDay]

Perhaps your choice of a super-tight match-accurate barrel for SHTF might be reconsidered. :)

[hAkron]

The Lyman 9mm and .380 gauges that I have are cartridge gauges and will show if the bullet is below or above the SAMMI length, but the Wilson I have in 357 sig is just a cartridge gauge. It's a good starting point if you want to make SAMMI spec ammo, but what you really want to do is make ammo optimized to your guns, so your barrel is probably the best case gauge.

[Walkalong]

Per Wilson's product description it does
Hmmm. So it does. I have never noticed, and I have one (http://www.thehighroad.org/attachment.php?attachmentid=120302&d=1272453749).

One thing it cannot check, is where the bullet will hit the lands in your barrel. That (http://www.thehighroad.org/showthread.php?t=506678) is what is getting you.

[rcmodel]

+1

That is exactly what I have been trying to say for the last 24 hours, without success.

rc

[rfwobbly]

Here's a cartoon of what RC is trying to tell you.....

https://lh3.googleusercontent.com/-dScRenzwZzE/Tz3NEksXtcI/AAAAAAAADOU/_pS6NKuOtrU/s720/Bullet%2520Shapes.jpg

The SAAMI spec, for which your cartridge gauge was designed, only makes sure the OAL doesn't go longer than 1.169" so that the cartridge is sure to fit into the MAGAZINE.

Plenty of pistols have short leades which restrict the OAL to much shorter dimensions. And that will vary with different ogive shapes. That's why the BARREL is the reloaders best tool for determining OAL for each individual bullet.

If your barrel's leade is extremely short, then you simply may not be able to use some shapes or brands of bullets because the OAL might be too short to feed correctly. Other bullets (the Hornady XTP is one famous example) may need to be seated .040-.060" shorter than the manufacturer suggests. May I suggest sticking with 124gr RN until you can figure out what does and does not work. Another suggestion might be to call Berry Mfg and order their "9mm bullet assortment" which is not listed on their web page. That's an inexpensive way to get 10-12 different bullets to play with.


Now you're starting to reload !! ;)

[kb58]

Here's a cartoon of what RC is trying to tell you.....

Ah something I can relate to, cartoons, I get it now. Since these are ordinary round nose, AND the OAL is within spec, AND because most of the rounds fit, it doesn't seem like bullet shape is the issue. I have applied a marker to the casing of some of the worst but haven't applied it yet to the bullet itself. I will do so and report back.

And yes, it does push me toward reloading, though a recent thread here on lead-poisoning did make me realise that it's not something to be taken lightly, for many reasons.

[Walkalong]

Have you tried this yet?

http://www.thehighroad.org/showthread.php?t=506678

[kb58]

That's a very interesting thread, thank you. For what seems like for such a simple thing, a round is a precision assembly.

[popper]

Bullets, cast or jacketed are not always 'spec' even in the same lot. RN 9mm are hard to seat exactly straight, you can seat a few thou. deeper to accommodate 'out-of-spec'. Crimp also may also cause a problem. I only use a case gauge for bottle-neck cases and then double check with the chamber. Casting and reloading is not dangerous - just don't eat the lead and wash your hands after using lead.