Head Space Gauge / Throat Reamers

rkittine

rkittine

Member
Head Space Gauge / Case Neck Reamers

Being new to this sport, I am still trying to both shoot and amass the required bits and pieces. Do I need to get Head Space Gauges made by the same gunsmith that built the rifle? Or, can they be made from the original reamer print and / or some type of measuring.

How about neck reamers to take out the donut but not effect the rest of the neck?

Thanks, Bob
 
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The headspace is set when a barrel is chambered, and FL dies are not set from a gauge but from measurements taken from fired cases, with the understanding that fire forming shots and the next two or so may not take a case to its maximum shoulder to head measurement, and it is that measurement that you need to set your die properly (IMO). Shooters do not use reamers to clean their chambers. It can be done with ordinary cleaning tools. The term doughnut is usually reserved for a thickening at the base of case necks that interferes with the seating of bullets in chambers where the full diameter part of the bullet must be seated at or below the neck shoulder junction. Unlike long range shooters that seem to believe that trimming for minimum gap at the end of the neck portion of the chamber, short range shooters have not found this to be an advantage. Years ago Tony Boyer had specified his chambers for a maximum case length of (I believe) 1.500 instead of the usual of either 1.515 or 1.525 depending on the manufacturer. He did this so that he could trim for minimum gap at the end of the case neck. The one time that I was privileged to speak with Tony was when he was at Speedy Gonzalez's shop in Texas, in the late 90s when I was writing for Shooters News. In the course of that conversation I asked Tony if he had found any advantage that way, and he told me that he had not. Jumping forward to more recent times, if you review the six video segments of Jack Neary's presentation on Youtube, in one of them he will discuss trimming cases. His chambers allow for a maximum case length of 1.525 and he trims (frequently) to 1.490, leaving a gap of .035. It may be remembered that Jack has shot on the US World Benchrest Championship team and has accumulated a fine record in competition over the years. The buildup of powder fouling at the end of the neck part of the chamber only extends back a short distance. Beyond that the usual cleaning methods keep the neck of the chamber clean. If you cases are never near the end of the chamber, because they are kept properly trimmed, there will not be any interference at that point. I have the use of a bore scope and have used it often enough to know that this is the case. Typically my barrels will show no buildup in this area or if they do it is slight and does not represent a restriction at the start of the freebore. Worry about reading flags and staying in tune.
 
Don't know about you all but them flags just keep waving the appendage that is one off from one side and two off from the other on each hand, at me.
 
Boyd,

I was recently reading Tony's book for the third time. He had a section on why to get a Head Space Gauge. I do know that the head space is set at the point of chambering and attaching the barrel.

My mistake on calling that a Throat Reamer, I meant inside case neck reamer, i.e. only to remove and donuts if they develop. I have changed the wording.

Bob
 
So, what would you use a headspace gauge for, to check your gunsmith's work? Have you checked all of your factory rifles? One time a friend got a fancy Remington varmint rifle in .223. It came with a HS Precision stock and was all stainless including a fluted stainless barrel. We checked the headspace and the bolt would close on a no go gauge. I have to say that I think that this is a rarity, but it happened, just like the fancy model 70 that came to my friend's gun shop with a smoothbore barrel and evidence that it had been proofed on the bolt face. Generally, I do not want my barrels to be at absolute minimum headspace, but of course I do not want the bolt to close on a no go gauge either. For 6PPCs when you turn your first necks you will find that because the top of the shoulder becomes the bottom of the neck when you expand to 6mm, you can do a custom fit with quite a bit of room for adjustment. My last barrels were done .0035 over minimum (on purpose) and I still have to take a very light cut on the shoulder so that the bolt close effort will not be excessive. The reason that I do not want my chambers at minimum is that you are more likely to run into die setting issues with shell holders running into dies if they are. Typically comparing new (rimless) brass of a caliber that does not require fire forming to reshape the case we may see cases that are .004 to .006 under minimum chamber headspace. As long as there is only one firing that has that much clearance there will not be any problems. Every new case or factory round that you have ever fired has had this issue.
 
Thanks Boyd, I am away until next Wednesday or later, but when I get home I will re-read the section in Tony's book, that triggered me wanting to buy these. Bob White called me this morning and I will le you know what he told me about the case neck reamers.

Bob
 
I understand completely about the use of reamers to remove doughnuts that can form at the base of case necks. While the need to remove doughnuts is obvious in situations where chamber throat length is such that the full diameter part of seated bullets falls within that area, many have said that they do not believe that there is any effect when that is not the case. To be fair, some believe that there is, but I know of no real evidence proving it, and I have never experienced any issues that I could trace to doughnuts shooting typical short bullets in a typical .060 freebore 6PPC chamber. The only reason for my concern about a new benchrest shooter thinking that he needs a headspace gauge comes from reading posts where shooters were under the impression that using such a gauge to set their FL die was the correct procedure. For a variety of reasons it is not.
 
Neck Reamer

rkittine said:
Being new to this sport, I am still trying to both shoot and amass the required bits and pieces. Do I need to get Head Space Gauges made by the same gunsmith that built the rifle? Or, can they be made from the original reamer print and / or some type of measuring.

How about neck reamers to take out the donut but not effect the rest of the neck?

Thanks, Bob
Click to expand...

I don't do anything about the donut unless I absolutely have to. If you have a long bullet short throat situation that places the bearing surface of the bullet near or past the donut then it is necessary to remove it.. I have had success with K&M neck turning pilots with the cutters on the end of the pilot. Others have a different experience. Bottom line, if the bullet doesn't touch the donut don't do anything.
 
Thanks, I am not worried about it for my 6 PPC but I do shoot Long Projectiles in my 6mmBR and my 6.47L. Sinclair has neck reamers that fit my Wilson case trimmer. It looks like you can get them to ream out all of the neck or get a slightly different diameter if all you want to do is remove any donut that develops. Maybe I should just hold off until I see that it is a problem and then go from there.

Bob
 
There is another option that has commonly be used for this. In the past Forster has offered custom diameter reamers. this solves the problem of matching a reamer to the ID of necks, either sized or as fired. Checking just now on their web site, apparently they still do."Neck ReamersThick case necks can cause high chamber pressures and flyers. The Forster Neck Reamer mounts in the cutter of a Forster Case Trimmer in place of the pilot and removes the excess brass from the neck walls.The Neck Reamer is manufactured from high-grade, wear-resistant tool steel and ground .0025″ to .003″ over the maximum bullet diameter. The staggered tooth design cuts the brass smoothly without chattering.Also keep in mind when using your Forster Neck Reamer:Neck reaming should be performed only after the cases have been fired with a full load and before the neck or full-length sizing operation.Wall thickness can be measured with a tubing micrometer, but a simpler test for excess brass in the neck area is to slide a bullet into a fired, unsized case neck. If you feel interference, the neck should be reamed or outside neck turned.Use neck reamers before resizing. Exceptions to this rule are:NR1220 – .220″ diameter reamer for .224″ bulletsNR1239 – .239″ diameter reamer for .243″ bulletsThese are common sizes that reloaders use to ream their cases just before seating bullets. These three sizes are kept in stock for those who intend to ream after the sizing operation just before seating bullets.Wildcatters often require specially sized reamers when converting brass from one caliber to another.We grind many other special sizes as needed. You tell us the size you need and we’ll grind it to your exact specifications. A nominal special grinding fee applies. Our quick turnaround service adds a versatile case preparation tool to your Forster Case Trimmer System."I may be dealing with this situation in the near future, depending on the throat length of a 6BRA that I am having chambered. I understand that Forster offers a one piece die for this caliber and of course they will open up die necks to your desired diameter fora small fee. In the past I have found that these dies are a handy and affordable way to size necks all the way down to the shoulder of a case, if that is needed prior to a light cut on a case neck. I think that they would also be the way to go for cutting out doughnuts given that bushing dies cannot quite reach that far. Another, more expensive route might be a custom ream die. For those that have lathes or mini lathes none of this should be a problem. Case necks can be forced onto a mandrel that has been cut , and is being used without being removed from the the chuck. The case turns with the mandrel that has forced the doughnut to the outside of the neck where it can be turned off. This method has also been use for initial turning of necks. Rather than simply using the lathe to rotate a conventional neck turner. https://www.youtube.com/watch?v=1OxYQFZAn7c
 
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Thanks Boyd, Looks like Wilson offers the same thing and also calls for about the size size over the nominal bullet diameter. Bob
 
Although I am very much in favor of the Wilson trimmer's method of holding cases for trimming, I am not sure that I would want the case to be held that rigidly when reaming the insides of case necks. I see that Wilson can make custom reamers but that there is a lead time issue (probably the same for Forster). If a case has already been turned and develops a doughnut the thing that I would want to avoid is it being rigidly held and or having a reamer such that a cut was made down the length of the inside of the neck, and that if such a cut took place, that more material would be removed from one side than the other, creating unevenness of case neck thickness, or thinner necks. One of the things that I played with a bit with my 6.5 x 47 cases, that I only skim cut the necks to increase loaded round clearance slightly, was to expand the necks and turn them at .277 and then use a one piece die to size them back to 6.5. The plan was to put off the formation of doughnuts by having the turned neck thickness extend very slightly into the top of the shoulder. Because I had not had the Forster die lapped out in the neck, I had to expand the necks slightly. I sold the barrel and brass before I had a chance to shoot those cases, having decided to build a 6BRA on the same action and stock. For that project I plan on turning to finished thickness before fire forming which should result in the bottom of the neck being pulled back into the top of the shoulder, which should put off the formation of doughnuts if I pay very close attention to shoulder bump.
 
I will stick to the basics until I learn a whole lot more and I am a Newbie, as you know, at this. I do need to spent more time with a trigger than on the web.

Bob
 
rkittine said:
Being new to this sport, I am still trying to both shoot and amass the required bits and pieces. Do I need to get Head Space Gauges made by the same gunsmith that built the rifle? Or, can they be made from the original reamer print and / or some type of measuring.

How about neck reamers to take out the donut but not effect the rest of the neck?

Thanks, Bob
Click to expand...

OK......first things FIRST.

This post is specifically to you and to this op, it doesn't reply to, comment on, amend nor otherwise refer to any of the other excellent answers.

And, as usual, I'll take this post off in a whole nuther direction......

This is my answer, there are no others like it, it is mine


My comments will possibly be taken as offensive, when they are, the fault is mine.

rkittine said:
Do I need to get Head Space Gauges made by the same gunsmith that built the rifle?
Click to expand...

You ask about Headspace Gauges..... now here's a sticky wicket. It is my considered opinion that the "headspace gauge" referred to by Tony, at least those ref'd on pg 156 of his hardcover edition is something more commonly called a "gizzie."

NOW, let me digress, let me TAKE some of your time in hopes of SAVING time down the road. And I'ma pick on Tony Boyer some...... rightfully The King of Benchrest, but not specifically the best teacher of the sport. It's been said that Tony's "forgotten more than most people know about BR", and this is TRUE :)

It's also "the problem."

And let me digress a liddle more..... there is one solid TON of information on this, the premier Accuracy Board on thee net. There is also a LOT of confusion both internally and more specifically because there's an internal "language" to this sport. Same as any other sport.

It's also "the problem."

I say this to you and to all others with questions, "Please Understand, We Don't All Hear The Same Things.... We're Not All Walking The Same Piece Of Our Accuracy Journey.". . . . . . COMMUNICATION IS HARD!! But we all try help. And I beg of all folks asking questions, BE SPECIFIC, ask the question again if you don't understand the answer.

And then ask AGAIN....

So, back to the headspace gauges. You do not need your own headspace gauge. But you DO need a device for setting, measuring, comparing headspace! This is commonly called your gizzie (or gizzy) ....... (((But NOT Gizzard))).....

KaPische??

Typically a BENCHREST gunsmith will supply you with a little round/square/rectangular gage/gizzie made by running the reamer in just far enough to encapsulate the shoulder...... with this GAGE you can measure your headspace. By measuring your headspace you can set your sizing dies from a location remote to your rifle...... BUT!!!

Y'UGE BUTTT!!!

This is all predicated on another concept that gets inconveniently left out of the conversation....When a BR RIFLE is assembled by a BR GUNSMITH and used for BR COMPETITION said gunsmith MATCHES THE DIE TO THE CHAMBER.

"This Is My Sizing Die, It Fits MY Chamber And ONLY My Chamber" (there are others, but they suck)

AND..... when you've GOT this scrupulous fit you most commonly set your dies by setting right at the rifle and "trying your fit" until it's perfect. This is only applicable if your dies MATCH your rifle. By this I mean they are MADE with, or fitted to YOUR rifle.

Let me just be frank....... I dunno what else to be....... THIS WHOLE CONCEPT (and the bulk of Tony's book) is completely unrelated to "normal" reloading. Perty much everything Tony talks about DOES NOT PERTAIN TO 99.9% of all the "accurate" rifles on this planet! Even those cobbled together by some schmuck to "benchrest standards" and using "benchrest components" simply DO NOT RELATE TO TONY'S BOOK!

Now

rkittine said:
Or, can they be made from the original reamer print and / or some type of measuring.
Click to expand...

Short answer, "NO"

and


rkittine said:
How about neck reamers to take out the donut but not effect the rest of the neck?
Click to expand...

OK....... now here I could go on for hours BUT, aside from pissing off all the Olde Phartes and crankypoos on the board, (some of them are already steaming) it would be a sensory overload. I'll make a couple quick statements and pray they help. They may make NO SENSE right now but down the road they will.

#1- Donuts are an artifact of improper fireforming and maintenance. They DO NOT HAVE TO OCCUR and can be prevented entirely on rounds from 6PPC up to blown out 50BMG's.

#2, IF you've donuts, and IF you're finding yourself trimming cases YOUR CASE MAINTENANCE REGIME (reloading methods) are screwed up!


(OOOHHHhhh BAYBieee, I can feel the heat from here!)


(((to all the haters, "Bugger Off go whine somewhere's else! I'm trying to help!")))


LOL



So, I'm gonna' ask you a favor. IF this has been helpful, IF my answer or any of the others has provided any insight, when you've more question please ask only 1 single limited question at a time :)

This board is 'tarnally KLUDGED at the moment. I spent an hour on this pig last nite and when I hit the 'submit' button it went away...... and I did too...... so, please bear with the unclear answers on my part......all my 'spressions are gone.

hth



al
 
Thanks Al,

I appreciate the insight. No need to remove the post as far as I am concerned.

Part of my problem is that I read too much and have more money then sense or time to go to the range on weekends when there may be others there to help guide me.

I should take a picture of my loading bench and show all the brand new things that I have never used so far and probably will be a while before I do. I started out, and continue to shoot 600-1,000 yard and my exposure to reloading for that regiment is much different from what I have been direct to do for this part of the sport. I have only custom dies for each of my centerfire bench rest rifles.

My LR benchrest rifle are built for heavier, longer projectiles extending much farther into the necks. My foray into 6PPC has been filled with questions, which Boyd has taken the time and patients to help guide me. First rifle with a tight neck requiring neck turning, first rifle requiring case modification and fire forming. I am going to Bob White's BR Seminar and Clinic again this year and am working on getting some direct instruction from one of the other instructors.

Bob White and I chatted yesterday and he set me straight on some things including what you have said and what Tony meant as you pointed out. I know understand the difference.

Thanks Again , Bob
 
I'm jus' sayin'...... you can avoid thee donut by feathering thee shoulder
 

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I need to figure out how to do that. I do not seat deep on the 6PPC though as I am using 60-65 grain projectiles as compared to the 105s I use in other 6mms.

Bob
 
Benchrest has evolved to the point to where you have to have to set up a barrel for a specific bullet.

When I built my 284, I reamed the chamber to specifically shoot the 180 Berger Hybrid. That is a very long 7mm bullet. This just about negates the use of 165's and shorter, unless I happen to find one that really likes being shot at .150 jump.

The advantage is you never have to worry about the donut, because the straight portion of the 180 grn bullet shank will never get near it.
 
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That is the case with my long range rifles. I am just learning though with the 6PPC and my little short 60-65 grainers.

Thanks Everyone, Bob
 
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