Shoulder Bumping & Case Head Clearence


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Walkalong
February 11, 2010, 05:34 PM
I got out my old .222 Mag reloads the other day. I intend to shoot those few up and then load some more.

I used to check shoulder bump for it using a Sinclair bullet comparator (http://www.sinclairintl.com/product/5581/Bullet-Comparators), which I can't find (arghh), despite having seen it recently. It isn't really intended for that, but it worked OK.

I could just order this (http://www.sinclairintl.com/product/8809/Case-Gauges-Headspace-Tools), but I am not very patient, and was bored since I had nothing to do today after getting my check up out of the way this morning. I have a small hobby lathe, so I decided to make a tool to do it with.

I had a piece of 3/4" steel rod, so I whacked off a piece with a hacksaw, chucked it up and faced off both ends. Then I drilled a .250 hole through it on the lathe, and cut a short 23 Degree "shoulder" in it. I made it long enough to work with loaded rounds if need be.

It will work with .222, .223, or .222 Mag as they are all .22's and have 23 Degree shoulders.



Head Clearance Tool/Shoulder Bump Gauge for .222, .223, & .222 Mag

http://www.thehighroad.org/attachment.php?attachmentid=115367&stc=1&d=1265927085


Gauge in use - It's laying on half of a barrel "vise" I used for removing my 9MM AR barrel to put on a free float tube.

http://www.thehighroad.org/attachment.php?attachmentid=115369&stc=1&d=1265927185

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243winxb
February 11, 2010, 06:35 PM
Nice job Walkalong. This i made quick to check 223, told me i had a bad Dillon shell plate. Click photo for larger pic. http://i338.photobucket.com/albums/n420/joe1944usa/th_Comparator_001.jpg (http://i338.photobucket.com/albums/n420/joe1944usa/Comparator_001.jpg)

Walkalong
February 11, 2010, 08:08 PM
Yep. It ain't gotta be fancy. :)

JimKirk
February 11, 2010, 10:51 PM
Nice job there Walk!

I just goes to show that it doesn't really matter what you use to measure, only that it is consistant between measurements. You could have used the hole with out the sloped shoulder and it would have worked just the same, but that was a nice touch, it will help keep the case aligned better too.

If you had step drilled it on the other end bore diameter and put a leade, you'd had a bullet and a case comparator combined.

Nice tinkering!

Jimmy K

Walkalong
February 12, 2010, 09:48 AM
To use just the hole it would need to be bigger in diameter to get close to the datum line on the shoulder.

I have a short piece of a 6MM barrel with the reamer run partly in it to check the shoulder on 6PPC cases. It was done by a gunsmith.

A short piece of .22 cal barrel is what would be best for making a piece to use as a bullet comparator. Got an old one laying around?

JimKirk
February 12, 2010, 11:03 AM
http://www.thehighroad.org/attachment.php?attachmentid=112916&stc=1&thumb=1&d=1263149945


Got a lot of old barrels laying around .... but they are hooked to some stocks!

I use the Sinclair # 2 hex nut looking thing(comparator) for shoulders, usually the .338 hole or which ever fits best for the shoulder measurement.

I use the #1 comparator for the bullets , it covers all the calibers I have.

I Use my calipers for the measurement from the top of the comparator to the base of the brass, if I want to get real ticky, I drag out the Indicator dials and base.

Before I purchased the Sinclair Comparators, I used a large hex nut and drilled holes that fit what I needed.

Like you said It ain't got to be fancy to work!

Jimmy K

bracer
February 12, 2010, 11:19 AM
Stoney Point Products, now Hornady makes a Headspace Guage with various inserts and Redding sells a Competion Shellholder Set which will allow you to resize a cartridge so that the shoulder is moved back a bit so that the cases are not over worked. I use both, the tools work.

JimKirk
February 12, 2010, 11:27 AM
And all those products were probably first made up by some old codger like Walkalong, while setting watching it snow in Alabama!

Jimmy K

ants
February 12, 2010, 11:54 AM
AC said: A short piece of .22 cal barrel is what would be best for making a piece to use as a bullet comparator.
Now that is good thinking.
Hmm, I have old sizing dies. Seating dies, too.

bracer
February 12, 2010, 12:01 PM
Jimmy K-- You are right ,some our best rounds and tools came from wild catters and home hobbiest.. I started reloading in 1953 with a Lymon Tru Line Jr press and small diameter neck dies. Military surplus 4895 and 4831 was the powder for the 100 and 130 Gr bullets for my 270. Over the years I got some the tools the bench rest shooters use for reloading my varmint rifles. I like new ideas .

USSR
February 12, 2010, 12:53 PM
And all those products were probably first made up by some old codger like Walkalong, while setting watching it snow in Alabama!


Hey, I'll have you know, Walkalong is a young codger!:D

Don

JimKirk
February 12, 2010, 01:07 PM
Yea!

But it is still snowing in bama!

And GA too!

Weather lady on Fox said it was the first time that snow has been on the ground in all fifty states at the same time!

So much for Al Gore's global warming!

Jimmy K

Walkalong
February 12, 2010, 01:35 PM
Yea, it's snowing, and the worst is yet to to come, if the weather folks have it right.

Called "emergency" managers meeting this afternoon. :rolleyes:

Here is a pic of the Surgery Center next to us. We take care of the hospital, the surgery center, three MOB's, and two Pri-Meds.

Walkalong
April 28, 2010, 07:41 PM
Made one for .308. My sons father in law bought a Steyr .308 bolt gun. I am going to help him load for it.

I made one for .22-250 for a fellow THR member. I was going to cut it for .22-250 on one end and .223 on the other end, but my dull bit went off center, so I wasn't able to do both ends. I need to re-do it now that I bought some new bits. :)

JimKirk
April 28, 2010, 11:02 PM
Nice work again, I see you've been busy with the lathe again.

Jimmy K

dc.fireman
May 14, 2010, 03:03 PM
Walkalong, if you ever decide to mass produce these, I'll buy it! Hell, maybe two or three!

Walkalong
May 14, 2010, 03:32 PM
Nah. I could never compete with the Sinclair tool (http://www.sinclairintl.com/product/5574/Case-Gauges-Headspace-Tools), or Hornady tool (http://www.midwayusa.com/viewproduct/?productnumber=479704), which is an excellent way to do it.

Stoney Point used to make a bullet comparator set, but must have sold the idea (http://www.dillonprecision.com/content/p/9/pid/24083/catid/8/Hornady__formerly_Stoney_Point__Bullet_Comparator), since they no longer sell one.

Walkalong
May 14, 2010, 03:38 PM
I made, and mailed, the .223/.22-250 gauge.

fguffey
August 3, 2010, 12:31 PM
Walkalong, you can do better than the Hornady, L.E. Wilson and the tool I call a contraption, I do and all I use is what most would call junk, on occasions I travel to Alabama to visit family and my wife wants to see a Hoover HS football game this year, the family lives in Norther Alabama near Huntsville. So let me know and I will bring some DATUMS, those are those things I find at gun shows that are sold as miscellaneous junk.



F. Guffey

Walkalong
August 3, 2010, 01:38 PM
A pic?

I'd love to know what a datum is. I do know what a datum line is. (I think) I read your posts with interest, although you are hard to follow at times. Pics with your posts would be great.

AC

fguffey
August 4, 2010, 12:56 AM
Walkealong, I have a set-up table, the top of the table is a datum when measuring height.

Again, the datum for a case and or a chamber is a round hole or circle, the diameter of the hole for the 30/06 is 3/8 " or .375.

I make a seating tool for a 25 cal like the 25/06 that is similar in appearance to the tool you have illustrated except it is used for seating bullets with neck support, the tool sets on the shoulder, the first cut supports the neck and the second cut centers the bullet. The seating die is one of the most overbuilt tool the reloader owns, I can use a can crusher to seat bullets with this tool if the base of the crusher is parallel to the crusher when lowered.

The ideal gage for measuring case length from the shoulder (datum) to the head of the case would not have a shoulder, it would have a hole the shoulder of the case would sit on,

Rather than take the time to look up datums I make them up, my case my chamber my datum, the results is the same.

As a suggestion the next time you chuck up a piece in the lathe, cut a hole through it that will accommodate the neck, then make a straight bore cut on the bottom instead of an angle, this will allow the case to center on the neck and sit on the datum (diameter of the counter bore/second cut), then remove the tool from the lathe, stand it on it's end, insert a case and with a depth micrometer (other end of a dial caliper0 AND MEASURE FROM THE TOOL (DATUM) to the head of the case.

Again I determine head space first then size cases by transferring the measurement to the press, die and shell holder.

There are some that can not get past the datum as being anything but a line, all I need to know is the diameter of the circle at the datum, again I have no problem making one up for my use but the ideal the go-gage is a precession tool is lost on me, I can measure the go, no and beyond gages with my datum system, if I can do that what do I need the expensive gages for?

For those that have a L. E. Wilson case gage, insert a fired case in the gage, use a flat face punch on the head of the case and hit the punch so the case is driven into the gage, no shoulder, the case will require a little help getting out but the shoulder will indicate a datum, measure the diameter, it will be close, the ring on the case of a 30/06 will be .375 or close.

You are correct, what I do can seem to be vague to very vague, I have a motive, the motive is to provoke someone into thinking, more times than not I am only half successful, I provoke without getting some to think, there lost.

Thank you for asking.

If you want datums purchase R. Lee's book on modern reloading, or be like me purchase anything cheap that has round holes in it, bolt gage, wire gage, drill hole gage metric and standard and the list goes on and on.

F. Guffey

Walkalong
August 4, 2010, 08:19 AM
So what you are saying is to cut the tool to sit against a small portion (the datum) of the case shoulder instead of the whole shoulder. I thought about doing that. Probably would be a more precise measurement of where one is supposed to get the measurement from instead of wherever the shoulder is hitting against the angled part of my home made tool. I may play with that soon. Overall though, my little tool works well enough for me. AC

then remove the tool from the lathe, stand it on it's end, insert a case and with a depth micrometer (other end of a dial caliper0 AND MEASURE FROM THE TOOL (DATUM) to the head of the case.While I thought about cutting the tool the way you suggest, I did not think about getting the measurement this way. What about variances in the thickness of the cases head front to back?

JimKirk
August 4, 2010, 12:52 PM
Is that not the same as I do with the Sinclair Hex tool?

I'm measuring from the datum(where the hex hole contacts the shoulder) to the base of the brass.

I use what ever caliber hole for the cartridge so that it fits about mid way the shoulder.

I mostly use the calipers for measurement, but if I want to be picky I get out the magnetic base and dial indicator.

Jimmy K

GW Staar
August 4, 2010, 01:03 PM
So what you are saying is to cut the tool to sit against a small portion (the datum) of the case shoulder instead of the whole shoulder. I thought about doing that. Probably would be a more precise measurement of where one is supposed to get the measurement from instead of wherever the shoulder is hitting against the angled part of my home made tool. I may play with that soon. Overall though, my little tool works well enough for me. AC

While I thought about cutting the tool the way you suggest, I did not think about getting the measurement this way. What about variances in the thickness of the cases head front to back?

This has been a great thread, but finally you managed to confuse me.:o

First, in my mind a datum is a "start location" may be a physical point, a line, or even a point in time.

His datum is the point the shell hits the offset in the tool's bore, right? (the point from which head space is measured in the chamber) The other end of that length measurement is the rifle bolt surface, which is the same as the bottom of the case's head...right?........so.........what does the head's thickness have to do with it? What am I not understanding here?

Walkalong
August 4, 2010, 01:09 PM
As a suggestion the next time you chuck up a piece in the lathe, cut a hole through it that will accommodate the neck, then make a straight bore cut on the bottom instead of an angle, this will allow the case to center on the neck and sit on the datum (diameter of the counter bore/second cut), then remove the tool from the lathe, stand it on it's end, insert a case and with a depth micrometer (other end of a dial caliper0 AND MEASURE FROM THE TOOL (DATUM) to the head of the case.
Maybe I misunderstood him at first. (Probably)

Let me try again. Make your tool. Put the case in it. From THE OUTSIDE (this time) measure from the datum tool to the BASE of the case.

Still don't think it will work any better than my little tool. I may just not be getting my measurement from the correct datum line on the shoulder. It may be up or down from it., but it still works for me. Get a reading. Size the case until the shoulder is pushed back .001 or .003 or whatever one desires. Done.

GW Staar
August 4, 2010, 01:36 PM
Maybe I misunderstood him at first. (Probably)

Let me try again. Make your tool. Put the case in it. From THE OUTSIDE (this time) measure from the datum tool to the BASE of the case.

Still don't think it will work any better than my little tool. I may just not be getting my measurement from the correct datum line on the shoulder. It may be up or down from it., but it still works for me. Get a reading. Size the case until the shoulder is pushed back .001 or .003 or whatever one desires. Done.

Your method works the same as long as the shoulder you cut is the same angle as the chamber's angle and not cut too wide (possible only if the smaller bore for the neck is bigger than the datum diameter...and you wouldn't do that). It creates a datum (starting point) at the same point on the case shoulder as the chamber does. His method requires a diameter measurement at that point in the chamber. Yours requires drilling an accurate angle. Same thing in my opinion, except that if you don't have the tools to cut that same angle, his method works. Seems to me the datum point you measure from is the key...however you get it. I would love to have tools like yours and a space to use them....other than my company shop.

BTW, elaborating, the word datum, comes from the word data, and a datum is the point from which you start taking data.

USSR
August 4, 2010, 04:15 PM
Is that not the same as I do with the Sinclair Hex tool?

Yep, that's exactly what the Sinclair Hex Nut does.

Don

JimKirk
August 4, 2010, 05:00 PM
datum is the point from which you start taking data

It would be "ideal" if that point is the "actual" point of contact(POC) between the brass and the chamber.
That POC determines headspace on a "shouldered" case. The POC may be the entire length of the shoulder or it may be a thin .001 or so. That all depends on how good your brass and chamber match and really your sizing die too. We all know that there are manufacturing tolerances... right?

I know that some probably laugh when I mention marking the brass or smutting the brass, but really, that is one simple way to find the POC of your brass.

Jimmy K

Walkalong
August 4, 2010, 07:31 PM
Your method works the same as long as the shoulder you cut is the same angle as the chamber's angle and not cut too wide
I cut them at the SAMMI angle for the caliber. Now what the chamber is cut at, we can only hope. ;)

I still use the Sinclair nut for getting a distance from the base of the case to the ogive of the bullet, but I like my little home made gauge for checking shoulder position.

fguffey
August 5, 2010, 10:05 AM
Datum again, not datum line, just datum, it is not simple, if it was we would not be having this conversation, for me? I use the companion tool to the press tool (the feeler gage) to change and or adjust the datum (point measurements are made from) when sizing cases.

I could drill a hole into my set up table that would be .375 in diameter and use the hole to determine the length of a case from the datum (top of my set up table) to the head of the case to determine the effect the case would have on head space, If I knew the length of the chamber from the datum/shoulder to the face of the bolt, again, I determine head space first.

http://www.z-hat.com/Cylinder.htm 30/06 cases that are 2.650 long from the head of the case to the mouth of the case and without a shoulder, just straight wall cases. This allows for the wildcatter, reloader, case formers and the few that determine the length of the chamber first first before firing in thousands.

OR I could fire a case THEN determine the length of the case from the datum (top of my set up table) to the head of the case THEN size the case and measure the length of the case from the datum to the head of the case to determine the amount of sizing.

A shoulder has varying diameters, the two angles of the shoulder form a cone, the point of intersection is called an apex, this is the reason I do not care what diameter the hole is used as long as I use the same hole when measuring, even if the hole has a radius.

A hole in my set up table turns the top of the table into THE DATUM LINE, but why, with two lathes, a mill.

One .375 hole serves as a datum for the 30/06, 7.7 Japanease", 25/06, 280, 270, 8/06 and can be used on any case that will not fall through the hole or a case that will fit through the hole.

F. Guffey

fguffey
August 5, 2010, 10:30 AM
Walkalong, you ask if you understood 'him' correctly, I am going to assume you were referring to me as him, AGAIN I did not say you could build it better, I never refer to SAMMY, Nothing I have matches his specs, he does not size my cases to fit my chamber, I do.

There is an outside chance someone reading this thread can say O I C.

If someone can drill and finish ream the hole to .375, they can make a datum, if they choose to cut an angle that matches the angle of a shoulder that works also BUT they have to understand there is no way to match SAM'S measurements as in from the DATUM (top of my set up table) to the head of the case, using the angle of the shoulder will be unique to the tool makers tool, but (as I tried to but failed) to explain if you could bore a hole to the correct diameter that would match SAM'S specifications on DATUMS you could measure the case from the datum to the head of the case and then look up SAM'S dimensions, again I do not have SAM'S chambers so all that information would be just NICE TO KNOW or something I could talk about but not something I use.

Again the effort on my part is made on the outside chance someone will come along that does not have their mind made up..

F. Guffey

Walkalong
August 5, 2010, 11:13 AM
True.

SAMMI only gives guidelines. "He" (Sam) does not know what your chambers actual measurements are.

Since I do not have the proper reamer, I can not make an exact .375 hole. I am sure I could get really close though.

Why .375, by the way?


"him".... Sorry, I should have said F Guffey

GW Staar
August 5, 2010, 01:02 PM
I Think .375 is arbitrary to a point. If you measure shoulder diameter at the exact center of the shoulder (between the smallest and largest diameters) according to SAMMI, it should measure .390. It appears he picked an appropriate number a little smaller than that...because he wanted too. Maybe smaller is insurance against a really loose chamber?
Like he said, it should work for any brass that won't fall through .375". .390" should work just as well in most cases....depends what bit you have that will bore bigger than the smallest shoulder meas. but smaller than the biggest shoulder meas.

What gets confusing to me is this: What if the shoulder angle in the chamber is a little bigger than the one on your tool? Then moving the shoulder of your brass back 2 thousands gauged on your tool, will move it back less in the chamber, and vica versa if the chamber angle is smaller....I think.:scrutiny:

Is this why he's advocating two bores only, verses two bores and a angle reamer between? Oops, shoulda looked at your picture again, shoulda said, ....verses a bore and an angle reamer.:o

Walkalong
August 5, 2010, 02:09 PM
Not to mention the angle in the sizer die. ;)

fguffey
August 5, 2010, 03:22 PM
Somewhere half way between here and there and in the center of the shoulder? That is the reason I believe most of this stuff is made up out of thin air, that would be a neat trick and every chamber mentioned, 30/06, 8/06, 280, 270, 25/06 7.7 would require it's own datum, as stated before all the chambers mentioned share the same datum (.375) plus many others.

.375 is the diameter of datum for the 30/06 because SAMMy says it is, I have no ambition to change it, as I have said before, I have 62 chamber reamers, cutting a shoulder for a case to sit against is not a problem, when cutting a chamber it is just as easy to take a few minutes to make a chamber gage out of a worn barrel, the only numbers to keep up with is case head protrusion AND the ability to measure protrusion from the barrel face and the face of the chamber gage to the case head,

Again, look at R. Lee's book on modern reloading by the same name, on each (most) of his case illustrations he took the time to list the diameter of the datum and the distance from it to the head of the case, I do it back wards, I determine the distance from the datum (shoulder) of the chamber to the face of the bolt first then adjust (transfer the measurement) the die to the shell holder in the press, after firing I can always determine the effect head space had on the case when fired, instead of firing first to determine the effect the chamber had on the case when fired.

My choice of cases: A case that is too long from the shoulder back to the head of the case to chamber, example 280 Remington, it's shoulder is forward of the 30/06, 8/06 338/06 35 Whelen, 270 Winchester etc. by .051 thousands. The 30/06 shoulder is head of the 8mm57, 7mm57, 275 Roberts, 308 Winchester etc. when forming cases there is no excuse for having head space in a chamber. When forming no one is required to fire the formed cases, when forming a reloader can determine head space by knowing when to quit moving the shoulder back.

Again we all know the shoulder is not moved back it is erased, part of the shoulder becomes part of the neck and part of the case body becomes part of the shoulder, I have never been able to get BUMP out of that description.

F. Guffey

fguffey
August 5, 2010, 04:09 PM
Advocating a bore? the only way to measure the distance from the datum to the head of the case is with a bore, the bore is not the same for all chambers/cases, the only way to check a go, no and beyond gage is with a bore, the bore (diameter of the datum) on the 30/06 is .375.

When I form and or size cases for my chambers I can make up the numbers, when WE all measure to one standard we must us one standard, it is only for us to understand everything below .375 is below the datum (table top), that leaves us with measuring everything that protrudes above the table top again the table top is the datum because the shoulder is an angle, we can use an angle BUT we will not agree nor will our measurements agree with SAMMY, unless we have a go-gage, then we can us it to check the measurements then what I could do (but will not), and that is to use a but grinder to lower the face of the tool until it agreed

To the die and shell holder, size a case, do not lower the ram, rotate the shell holder and remove it from the ram and case at the same time then remove the die from the press with the case installed, measure the case head protrusion from the die to the head of the case, the protrusion should be .125, if you have a head space gage for the 30/06 and place it into the sizer die it should protrude .130 in the perfect world because the go-gage is .005 longer from the datum/shoulder than a minimum length store bought commercial case from it's shoulder to the head of the case,

To get the case out of the die install it in the press, install the shell holder onto the case and ram at the same time and rotate, then, lower the ram.

And before placing the go-gage into the sizer die remove the neck expander/sizer ball assembly, first.

F. Guffey

1858
August 5, 2010, 08:55 PM
My gunsmith makes up a bunch of "dummy" chambers that he cuts using the same reamer that he uses for the barrel. He gave me one for my .260 Rem the other day. Surely, that's the most accurate gauge to measure shoulder "bump" since the gauge and the actual chamber should be the same. Thus far, I've been doing it all by comparing fired cases to a SAAMI standard using Redding's Instant Indicator Case Comparator and have no complaints, but as fguffey and others have pointed out, this only works if the chamber of the rifle is cut to SAAMI specs or at the very least, close to SAAMI specs ... which hopefully it is.

:)

Walkalong
August 5, 2010, 09:02 PM
Hopefully.

Many Benchrest shooters use bushing dies cut with the finishing reamer that the smith cut their chamber with. I have two of them from different smiths. One matches the barrel on the gun right now. They are all pretty close though, assuming the smith did a good job, which smiths who specialize in Benchrest guns do.

Walkalong
December 18, 2010, 01:13 PM
I bought a .35 Remington (http://www.thehighroad.org/showthread.php?t=560791), so I needed another "gauge" to help set up my sizer. This time I tried fguffy's advice. (If I understood it right)

After drilling and then boring a hole to fit the neck, I bored a small amount to a larger diameter so it would hit in the middle of the shoulder, instead of cutting an angle to lay on the shoulder as on my previous gauges.

http://www.thehighroad.org/attachment.php?attachmentid=132390&stc=1&d=1292695887

JimKirk
December 18, 2010, 04:01 PM
Back on the lathe again?

I like what you've done. I think that the single edge contact point will give a better read than the whole angled shoulder. Using the smut/marker "tool" I refer to from time to time, you can find that contact point, sometimes it is the whole shoulder, sometimes just a thin point. I have rifles that do both. It may be at SAMMI called for point or other points never know until you use the "tool". I drill pressed a "larger than the Sinclair Hex nut" right after the first date in this thread, works well too. All that is needed is a before and after measurement to know how much the shoulder has moved.

Jimmy K

JimKirk
December 8, 2012, 03:37 PM
I know this is an old thread ... but I also know that there have been a lot of new folks that have joined THR since then ... thought that a refreshing would not be bad ...

Walkalong ... I like the idea of holding the neck close to straight when measuring the shoulder .... that is something the Sinclair Hex Nut does not do... you just have to make sure the nut is making contact all the way around the shoulder ... but your idea would make it easier and faster...

The same idea could be applied to a bullet comparator.... the neck sized hole with the "ring" to contact the bullet at rifling diameter...

Walkalong
December 8, 2012, 05:32 PM
I have the Sinclair hex nut as well. It is a little harder to hold square and get a reading with, but as you know, it works. While it was intended to get readings off bullet ogives for checking jump to the lands, it works with brass shoulders to see how far you are sizing them as well.

So yea, my little gauges are a bit easier to use than the hex nut. :)

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