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Old September 8, 2011, 08:22 PM   #1
Kayser
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Measuring 30-06 for Garand with Wilson gage.

So, I resized 24 rounds of once-fired Lake City brass. Ran it through the Wilson gage.

Of the 24 rounds, 12 measured up perfectly. Using a steel straight edge, I got a nice little wobble on the lower rim, but nothing was over the upper rim.

However, I did have 8 rounds where I got no wobble on the lower rim. Eyeballing it against a nice bright background, the case head is right at the lower rim. I mean just right there. Not even a hair's width below.

So my question is, is that sufficient/safe? Or should I really shoot for something just a tiny bit above the rim. By way of comparison, I ran a couple boxes of the unfired Lake City surplus through the gage and they all measured out correctly (wobble on all of them).

I don't mind tossing out a few pieces of brass, but if I'm just being a worry wart I'd rather keep em. On the other hand, safety is paramount to me, so...
Any thoughts here?

Also, any suggestions on how I might change my procedure in the future to get more consistency? I find it mildly disoncerting that a 1/3 of the cases were off tolerance, but 2/3 weren't.

Thanks!
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Old September 8, 2011, 08:51 PM   #2
bfoosh006
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Read these articles... ( it applies to the M1A / M14 reloading, but... a lot of it can be applied to the Garand reloading...

http://www.zediker.com/downloads/14_loading.pdf

and..

http://www.zediker.com/downloads/oncefired.pdf


Ultimately, ( IMHO )...you really want the cases to feed with no resistance into the chamber of both of these rifles.
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Old September 8, 2011, 08:54 PM   #3
Ideal Tool
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Hello, Kayser. While it is good to be as accurate as possible when it comes to handloading, I think you are worrying about nothing. Those Garands were built to function with mass produced military ammo, from various manufacturers..plus leaving room in their for fouling and dirt. Do you think every case that came off the drawing presses would check out as closely as the Lake City you have, when mnfg. under wartime conditions?
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Old September 8, 2011, 09:08 PM   #4
Kayser
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So if what I'm reading here is correct, a little bit on the short side is ok (more than enough shoulder setback, maybe leading to a little case stretching), but a little on the long side is bad (not enough setback, leading to dangerous bolt closure issues).

Yeah, I know I'm probably overthinking it. I tend to do that when I expand the calibers/guns I reload for. If you run through my post history you'll find me doing it all the way back to the .45 acp days
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Old September 9, 2011, 08:03 AM   #5
243winxb
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Fired brass from your gun should be put into the gage for a reference point. Then the full length sized brass should be slightly below where the fired brass was. If you want more exact measurements, buy a tool that gives readouts in the .001" s. RCBS Precision Mic. http://www.midwayusa.com/viewproduct...tnumber=622021
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Old September 9, 2011, 08:31 AM   #6
89blazin
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Being flush with the lower lip is where you want to be. I strive for that with my 7.62 LC reloads.
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Old September 9, 2011, 11:25 AM   #7
mehavey
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Q1: By "wobble," do you mean a sliver of daylight (under the straightedge)?
Q2: Are you in fact loading for a Garand? (I didn't see/missed that in the OP)
Q3: Have you checked the "long" cases for easy bolt closure ? (If a Garand, you need to disassemble the bolt/extractor to get a clean feel, and do this without any springs involved.) THAT will tell you if the rifle will handle the long cases.

Observation-1: Depending upon the condition/hardness of individual case shoulders, resized cases can exhibit different "springback" coming back out of the die. That you are seeing those differences is not surprising. Becuase of this I usually "bump" the case twice up against the final resizing stop to minimize case-to-casedifferences. The time to check whether more is req'd is right after resizing/before loading the case.

Observation-2: Barring your determination of exact headspace dimensions for your rifle (Garand as described above), it's best to fit to the minimum case gauge mark.

Observation-3:
Factory-loaded cases are all sized for minimum SAAMI headspace conditions. I would have been very surprised if the Wilson gauge showed otherwise.

Observation-4:
Reloaders should not depend on fired cases for resizing dimensions in their M1. Garand-based actions (M1 & M14) are notoriously hard on brass as they extract, and shoulders are actually blown forward as the bolt opens under pressure. Fired cases will therefore read longer as often as not. (Sometimes considerably longer.)

Note: I have also tried shutting the gas valve off in the M14 (so no extraction occurs), but even those case dimensions left me a little queasy.

Last edited by mehavey; September 9, 2011 at 11:32 AM.
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Old September 9, 2011, 11:40 AM   #8
Kayser
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Q1: By "wobble," do you mean a sliver of daylight (under the straightedge)?

Correct. By "wobble" I mean that I can rock the straightedge back and forth with my fingers, indicating the case head being slightly above the surface in question.

Q2: Are you in fact loading for a Garand? (I didn't see/missed that in the OP)

Yep.


Q3: Have you checked the "long" cases for easy bolt closure ? (If a Garand, you need to disassemble the bolt/extractor to get a clean feel, and do this without any springs involved.) THAT will tell you if the rifle will handle the long cases.

To clarify, I don't have any long cases in the sense that any of them protrude above the upper gage surface. 2/3 of them are between lower and upper surfaces, as desired. 1/3 of them are flush, or infinitessimally below the lower surface. My hope is that these are good to go - maybe they just experience a little more case stretch when firing. But I've seen enough pictures of blown up Garands that I want to sanity check everything.
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Old September 9, 2011, 11:53 AM   #9
mehavey
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Quote:
I don't have any long cases in the sense that any of them protrude above the upper gage surface
That's the NO-GO position. I'd simply check the longest case in the rifle itself. If the bolt closes with no resistance, you're G2G -- and at least have a handle on the rifle's headspace clearances for future reference in reloading those (currently) short cases.
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Old September 9, 2011, 12:08 PM   #10
maggys drawers
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+1 on what 243winxb wrote. Headspace tolerances on the M1 are important. Get a RCBS Precision Mic, learn how to use it and size your cases to fit your rifle.
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Old September 9, 2011, 12:47 PM   #11
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Mehavey makes the important points. I'll add in a simple test. Go to the range. Fire a round with the gas cylinder plug removed. This will defeat the semi-auto mechanism and let the case size to the chamber. Extract it gently by manually pulling the op-rod back.

That is not something you should do too often, as the gas will foul and possibly, over time, start to erode the threads in the end of the cylinder. I've used this technique repeatedly in experiments, but to do that I took one of the old style solid plugs and bored it out with a 1/4" drill to let it handle the gas venting.

Once you have a case that is accurately fireformed to your chamber, you can make legitimate comparisons to your resized cases. You really only need a couple thousandths of setback below chamber size for smooth feeding, as that's all there is between typical new brass and a minimum spec chamber. Keeping it close, but no less than that amount of setback maximizes case life. The sizing die will have narrowed the case even before the shoulder is set back that far, and that's the main thing.

To get the .002" setback accurately established, you'll need a comparator that sees thousandths. You can buy the RCBS Precision Mic shown earlier, or the Hornady case comparator adapter for calipers or the Sinclair version. However, you only need a comparative measurement and not an absolute one, other than to satisfy your curiosity about your chamber.

For comparative purposes, a basic dial or digital caliper will do. If you don't have one the $20 Harbor Freight 6" digital caliper is just fine. For .30-06, you can use the caliper with a 3/8" ID bronze journal bushing you can get from the hardware store for about $5. Use it as shown below. Just measure your fired case and zero the caliper (either dial or digital) it. Then put in a resized case and check that it is at least -0.002" smaller.

Again, the closer you get to that without having any less setback, the longer your brass will last. Most cases vary some, though, due to the springing, so you may want to target -.003" in order to have fewer re-do's.



That caliper was zeroed on a headspace GO gauge, and is showing the fireformed brass to be 0.003" over GO. You don't need to bother with the GO gauge unless you want an absolute measurement.
Attached Images
File Type: jpg 30_06 gauging headspace 2.JPG (46.4 KB, 747 views)
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Last edited by Unclenick; September 9, 2011 at 01:03 PM.
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Old September 9, 2011, 02:31 PM   #12
F. Guffey
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Straight edge? I use a straight edge 'AND' the companion tool to the press, the feeler gage, my light thickness gage is too hit and miss, I want to know in thousands, I also use a dial caliper and or a depth micrometer, when I have room I use a set up table with a feeler gage or a last work indicator and or a "Spot-on Indicate.

Then there is the Garand chamber, in the beginning additional clearance was added when the chamber was cut, all the 30/06 chambers in WW11 use the same ammo, .00024 does not seem to be much and there are those that claim no one could hold tolerance that close, it is in the book.

Full length sizing is full length sizing as in sizing a case to minimum length, minimum length as in over the counter, store bought, new in factory boxes, point being if new factory over the counter ammo will chamber how difficult is it to transfer the dimensions to a press, die and shell holder, Me? I determine the length of the chamber first instead of firing first to determine the effect the chamber had on the case when fired.

Then, when sizing there is determining the ability of the press, die and shell holder to size the case, without knowing how to determine the dimensions of the case after sizing or if the press, die and shell holder was effective,then there is the L.E. Wilson case gage, it measures the case from the case head to the the shoulder and from the shoulder to the mouth of the case, I have a chamber that is .016 thousands longer that SAMMY'S ideal of a perfect chamber when sizing cases for that chamber I add .014 thousands to it's shoulder. When checking the cases with the L.E. case gage the neck is flush with the top of the gage, when measuring the case length I add the .014 thousands, when measuring the COL (case overall length) I add the .014 thousands.

Chamber gages, I make chamber gages, not like any other chamber gages, so I have been told, my gages mirror the chamber.

The DATUM in the L. E Wilson case gage has a radius, to check the datum/radius place a case in the gage, with a soft drift and a light strike of a hammer seat the case into the die, when the case is removed the the shoulder will be concaved, for those with a set up table, last word indicators and or has command and understanding of the datum, well it is not my job to convince someone it can be done.

On another forum a prolific poster/reloader was using the Wilson case gage as as a chamber gage, and he has not spoken kindly to me since.

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Old September 9, 2011, 02:47 PM   #13
chris in va
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FL resize, trim, check for obvious brass defects and shoot the darn thing.

Sorry but this isn't a high performance/tolerance sniper rifle. It's an old battle axe with generous chamber clearance meant to function with just about everything the ammo plants could dish out.

More like an AK than an AR.
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Old September 9, 2011, 03:11 PM   #14
243winxb
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Unclenicks test is a good one. The M1 gas system is said to open a little to soon, letting the case stretch to a larger size than the chamber. This would give a false reading on any gage/tool.
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Old September 9, 2011, 04:29 PM   #15
wncchester
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The point of the Wilson "drop in" type case gages is to see if the reloaded ammo is within SAAMI standards for any rifle ever chambered for that cartridge. There is no reason to question that it does that very well; if a cartridge fits, it fits. ??
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