Reloading: A Few Concentricity Questions
I have been reading the thread on sizing, and your article on the Rifleman's Journal, man my head in spinning. I was hoping you could give me some advise, as always highly valued coming from yourself. I have a Remington R5 that I shoot in 600 yd. and 1000 yd. matches in a factory gun class. I want the straightest brass I can get using Lapua brass and Sierra 175's. Could you give me a die recommendation for a .308 with a factory chamber? I have Redding standard die set, and a Type S full-length bushing die with the correct bushings, and a Redding comp seater. I had been using the Lee collet set, but I did not like the way it left my brass looking. I'm just looking for the best I can get with non-turned brass and a factory chamber. Do I need to buy the Redding comp. neck die then run in a body die to bump?
Look forward to your reply when you get the chance.
The dies you have are perfect, no need to buy anything else. The body die, in my opinion, became obsolete when they brought out the Type S die, it's essentially the same as a body die with a bushing. Let's look at each factor, then get to a solution.
Your factory chamber neck is probably pretty large, I suspect it's between 0.342" and 0.345", measure a few fired cases, add 0.001" to the average and that's a good indication of the chamber neck size.
Lapua brass is relatively thick, usually close to 0.015" at the neck. Your loaded rounds are probably 0.337" to 0.338" diameter, is that correct?
If your loaded rounds are about what I estimated, then a sized neck in your standard FL die should measure about 0.335". That's after being sized down to somewhat smaller than that dimension and being popped open by the expander ball.
Let's think about the Type S bushing die for a moment. Assuming for the moment that your chamber neck is 0.344", fired brass is 0.343" and you would like to get to 0.335". That's a reduction of 0.008" which is best done in two steps to maintain concentricity. I would use a 0.338" bushing followed by a 0.335" bushing in the Type S die. Running the brass through the die twice shouldn't change the headspace or overwork the brass, there's no need for a second die.
If you happen to have a bushing type neck die, then you can use the neck die with the 0.338" bushing and follow with the Type S with the 0.335" bushing, but whether you use one die or two for the two step process, the outcome will be the same.
In my experience, the standard die will get you slightly better runout figures. However, the trade-off is that the brass might not last as long since you are working the neck more by reducing it below 0.335" (maybe a lot more) and using the expander to bring it back out to that size. Removing the expander is not a solution because then the neck will be too small and seating bullets will be very difficult and runout will actually increase - not to mention that the bullet has then become your expander so nothing was gained at all.
The ultimate solution is a standard die with the neck reamed to the exact size desired or maybe 0.001" smaller to allow for slight variations in brass. The downside to that is that you limit the use of that die to brass of a specific neck thickness. For instance, a die with a 0.335" neck would be useless with Winchester brass and one with a 0.331" neck for Winchester would over-work Lapua or Lake City brass.
If it were my rifle, I would use the Type S with two bushings and no expander. The concentricity will be acceptable, and that will allow you to experiment a bit with neck tension which may result in some accuracy gains. Small variations in concentricity, especially in a factory chamber, may not have a noticeable effect on accuracy. An added benefit to the bushing method will be increased brass life and at the price of Lapua, that's not a bad thing!
I've been reading this subject and have a few points I'd like to pass by you. I am doing this by PM just in case it's not valid. There is no point in skewing a good thread with a page full of comments on how this newbie, aka me, jumped in and managed to swallow both feet!
If I understand correctly, if you size brass without the expander ball in the die, you end up with brass that is concentric in its outside dimensions, i.e. the outside of the case is concentric with its longitudinal axis, but you end up with an irregular inside neck. If you run the die with the expander ball, you have a concentric inside neck but the irregularities are transferred to the outside portion of the neck.
Has anyone thought about mounting a cylindrical reamer to a sizing die? With the case neck being firmly held by the die, you would ream the inside neck to achieve the wished-for result, brass that is both concentric along its longitudinal axis and a concentric and round inside neck.
What is your opinion?
Nothing wrong with your question at all!
Thank you for responding to my query.
1. My understanding is that you use outside neck-trimming procedures once you have used a neck-sizing/FL sizing die.
2. I also understand that many processes that require the neck-sizing button to travel in and out of the neck can/may induce that neck to be off-center. This may be because the thread cut into the die might not be perfectly centered or that the locking nut may/may not be at a 90 degree to the axis of the threaded shaft.
3. I am not thinking of replacing the neck button in die processes; it provides an efficient method of processing brass for almost all reloading uses. I am more interested in pushing this reloading process to the next level. Take the following premise: you have a resizing die that does not use the expander button; you resize you brass using this die, which produces brass that is externally 'perfect'. This brass would then go through a process that ensures the inside diameter is correct for the projectile and neck tension that is wished for. Such a round would be, empirically, the perfect round to be inserted into a chamber.
4. I understand, as per your comments earlier, that a reamer would try to reach a center according to the resistance to its cutting. How much deflection do you think a reamer would have with a support, say 1/2 in. from the casing mouth? I am of course thinking of a bearing supporting the reamer within 1/2 in. of its cutting action into the case mouth neck. The reamer would then be fed into the neck in a controlled fashion.
5. I am still contemplating some tool that, within measurable values, can be axially centered to the longitudinal axis of the inserted brass's center.
I understand that all I am putting forward would mean additional work by accuracy reloaders. But the potential accuracy increase might be worth the development work. What do you think?
Hope to hear from you soon,
Let's take your questions and thoughts one at a time and see where we end up. I've numbered them for easy reference.
1. Yes, I outside neck-turn my brass and before doing that it is necessary to full length size it with a non-bushing die (unless the brass is unfired).
2. The expander button is usually not held with an unyielding degree of rigidity and will follow the neck as it exits the case. Lack of alignment or concentricity with the centerline of the die is not a major concern. Also bear in mind that the case is a fairly loose fit in the shellholder and is unsupported at the time that the expander button is going through the neck. Between those two factors, there is quite a bit of self-alignment in the action of the expander ball. Accordingly, the expander ball is not a major contributor to case neck runout. However, to the extent that it is a concern, an O-ring can be put under the locking nut for the expander stem and that will allow a bit more float to minimize any such effect.
3. Typically, when using bushing dies, no expander is used. The bushings are selected based on the neck thickness and the desired degree of neck tension. Of course the neck thickness can be varied through neck turning and the bushings come in a wide range of sizes, thus allowing for very fine variations in neck tension. Some people use a die with no expander ball and then set the ID by running a tapered expander into the case such as is used before neck turning. I may be wrong, but I don't think this is a material improvement over the standard expander ball and it is definitely no improvement over a correctly sized neck and no expander.
4. I don't think you can hold the neck reamer and the case with sufficient rigidity to prevent the reamer from following the hole. Even in a lathe, a reamer will follow the hole in front of it, that's one of the focal points of a good setup in barrel chamber reaming, for instance. Given the small scale of case neck reamers and the low rigidity of any tool with which you might hold them, as compared to a lathe, I'm not at all optimistic that it can be done without the reamer following the hole in the neck. More importantly, I don't understand what could possibly be gained over conventional outside neck-turning which is a simple and proven method of creating uniform neck thickness and very concentric body/neck alignment.
5. Consider that once the brass is outside neck-turned and then fired, you have the benefit of a 55,000 psi alignment tool to bring the centerline of the now evenly thick neck into alignment with the centerline of the case body. The end result is limited only by differential expansion/contraction rate (springiness) of various points along the circumference and length of the case body resulting from radial case thickness variance and to a lesser degree by the springiness of various points of the neck itself. However, these same factors would also limit the result with neck reamed brass (assuming reaming could be done to a satisfactory level of neck uniformity). With good dies and procedures, they'll stay that way for the rest of their service life. The idea of getting to the same end result by inside reaming seems to discount the value of the fireforming process in neck/body alignment along with overestimating the probability of being able to ream on center.
Phil, I don't like to just be a naysayer, but neck reaming was simply an early evolutionary step in the accuracy world on the way to where we are now - high precision outside neck-turning with readily available tools at a moderate cost. What you're proposing will require expensive, one-off tooling with no potential to do a better job and a significant likelihood of doing a lesser job. I enjoy thinking about these questions, it makes me really analyze what we do and why we do it and in this case, I'm convinced that outside neck-turning remains the best answer to the problem of uneven case neck thickness. Thanks for the questions!
by: German A. Salazar
There is no shortage of concentricity checking tools on the market today and it seems new ones keep coming to market so a quick survey of what we look for in a concentricity tool might be useful. I don't intend to cover every tool available, after all, this is all done on my own time and budget! However, I have three concentricity checking tools and a comparison of their features and ease of use might be useful for someone contemplating buying this type of tool. The three tools are: the old Sinclair, which is a traditional V-block and dial indicator tool; the Bruno's tool, a high quality unit which has some interesting features; and the NECO tool which is really a very adaptable case checking tool, not just concentricity although we will limit this article's coverage to concentricity.
This article does not address the question of the accuracy effect of greater or lesser concentricity, that's a topic for another day (if ever). We are simply concerned with the accuracy, ease of use, limitations and other features of the three tools covered. It's up to you to decide which one, if any, is worth your time, money and effort. I have all three and use them at different times for different projects; to me, all are worthwhile, but I'm a tool hoarder anyway. Let's have a look at them individually.
Sinclair (old model)
There are a couple of points to watch out for with the Sinclair tool. The first, which is common to all of these tools is to keep the V-block clean as it has a tendency to accumulate a bit of grunge and that can have a small effect on readings. The other is that the smoothness and perhaps accuracy of the tool can be affected by irregularities on the case base, including from the primer. I generally prefer to remove the primer with a decapping die prior to using the tool on fired but unsized brass. If the case has some nicks and gouges on the rim, such as a semi-auto's extractor might cause, it's best to dress these down before checking runout.
Visually the Bruno tool is a gem, the anodizing is bright, the polished pieces are well done and it uses a high quality lever-arm test indicator with 0.0005" gradations which allows for very precise readings. My first impression, however, was that it might be too small for some of the work I do, especially the .30-06. It really looks like it's scaled for the 6PPC, or maybe I thought that because it comes from Lester. Well, this was one of those ocassions when I was quite happy to be wrong, it easily handles the .30-06 and larger cases as you can see in the pictures.
Basic adjustment for case length is simple enough: loosen a lock screw on the tapered case mouth/bullet support and slide it to the desired location. The more challenging part is moving the indicator to the new location. The indicator is mounted on a tool post and while the holder is sufficiently adjustable, it is not easily adjustable. Frankly, it takes a bit of work to properly locate the indicator, but once that's done (a matter of a few minutes at most) it will hold its setting perfectly. The rear of the case is supported by two tapered posts. In the middle there is a central tower with an interesting case support: a vertical rod with a contoured case-riding piece that presses lightly down on the case to keep it from tipping upward from the finger pressure at the rear - quite clever and effective. The case mouth rides in a horizontal tapered post which also has a central hole in which the bullet tip rides when measuring runout on seated bullets.
Using the Bruno tool isn't very different from the Sinclair, you maintain a slight forward pressure as you rotate the case. However, the design of the Bruno with the end of the case hanging in the air makes it much easier to turn it consistently through a rotation. Bring the central case-rider to bear on the case tiny bit of downward pressure prior to starting; that keeps the case rotating smoothly but there is no need to press on the post while actually rotating. The 0.0005" indicator reads smoothly and really gives a better visual indication of runout than the 0.001" indicator that I have on the Sinclair. In part this is due to the smaller, more precise contact point of the lever arm indicator used on the Bruno tool. I should also mention that reading the Bruno is a lot easier since the indicator faces up, whereas on the Sinclair I have to crane my neck to look at the forward-facing indicator. The Sinclair is a good tool that has given me many years of good service, but the Bruno is a better setup for real precision.
This leads us right to the next important concept: don't shoot at a target while chronographing. I know that all the magazines show someone doing that and all your friends will tell you its not a problem, but those are the same friends who will tell you about shooting a chronograph. When you're trying to line up on something 100 or 200 yards away, it's not too hard to forget to check where the bullet's line of flight really is and at some point... A few extra bullets spent in shooting first through the chrono and then later on the target are a whole lot cheaper than a new chrono (or three). Let's do one thing at a time and do it well. There are even more reasons not to shoot on a target while chronographing which we'll cover later.
The following article by Ray Meketa is an excellent history of U.S. National Match rifle ammunition from the late 19th Century through the 20th Century and even into the 21st Century; we are very grateful to him for sharing it with our readers. We have previously featured Hap Rocketto's seminal work on this topic and Meketa's short piece on M118 Special Ball ammunition and this article continues in that vein. Ray has done an outstanding job of preparing this article which was originally published in the Jan/Feb 2010 issue of the IAA Journal and is reprinted here with the kind permission of the International Ammunition Association, Inc. For those with a greater interest in cartridge collecting, we highly recommend the IAA's website at www.cartridgecollectors.org . Every picture in this article can be enlarged by clicking on it.
U.S. National Match Rifle Ammunition
By: Ray Meketa
It didn’t take long for the Army brass to realize that the issue rifle was just as accurate as the specially made, and expensive, Long Range Rifle. Additionally, any increase in accuracy over the regularly issued 45-70-405 cartridge was found to be attributable to the 500 grain bullet rather than to the lengthened case or to the 10 additional grains of powder. They concluded that any rifle that a soldier had to use in battle was good enough for target practice and ordered that future competition be confined to service guns and service ammunition. With less than 200 of the Long Range rifles having been manufactured, the project was terminated.
By the mid 1880s the purse strings were loosened and the Army initiated a program of regular target practice for troops in the field. Competition shooting was recognized as a legitimate military activity and the standard 45 caliber rifles and 45-70-500 service ammunition were used by Army teams in both national and international competitions. The military value of marksmanship was finally beginning to sink in.
In 1903, Congress established the National Board for the Promotion of Rifle Practice (NBPRP) and the National Matches. At first limited to the military services using service rifles and ammunition, the program was soon expanded to include all members of the Armed Forces, National Guard, reserves, and civilians. The matches became an official function of the U. S. Government, first managed by the Department of War and later the Department of the Army. Competition consisted of both individual and team matches conducted at local, regional, and divisional levels, culminating in the National Matches at an appropriate range - now Camp Perry, Ohio. When competing in National Trophy (NT) or Excellence In Competition (EIC) Matches, cartridges would be issued on the line and no other ammunition was allowed.
The first matches held under the new programs included Army and Navy teams using the 30-40 Krag and service ammunition. The pre and post-1900 Krag ammunition, loaded with nitroglycerine based smokeless powder and cannelured 220 grain round nose bullets, was anything but match quality. It was nearly as wind sensitive as the 45-70, large groups at even the shorter distances were common, and constant cleaning was required otherwise fliers would occur with frustrating frequency. Many rifle teams continued to use the familiar 45-70-500 rifles, seeing no clear advantage in the new Krag rifles and ammunition. Dissatisfaction led to tests with different powders and bullets. Improved nitrocellulose type powders and smooth, un-cannelured, bullets helped to reduce barrel erosion, fouling, and group sizes. Barrels with different rifling types were tried. So called “Match” cartridges were issued several times between 1903 and 1907 but they were little better than regular service ammunition and, at times, even worse. These changes to improve the 30-40 were each partially successful, but even in combination they couldn’t transform it into a competitive cartridge.
The use of the Krag in competition was short lived. In 1903, the new clip-loaded Springfield bolt action rifle and the .30-03 cartridge were adopted as the Army standard. The cartridge used a new rimless case but fired the same 220 grain round nose bullet at velocities not much different from the old Krag. It was not a very good cartridge, often being out shot by the Krag. The cartridge was soon improved by loading a 150-grain spitzer bullet in a slightly shortened case at higher velocity, and the existing rifles were re-chambered accordingly. The Cartridge, Caliber .30, Model of 1906 was born.
The first commercial contract was awarded in 1909 to the U.S. Cartridge Co. (USC Co 3 09). Those cartridges duplicated the 1908 Frankford Arsenal cartridges. In 1910 specifications called for the cartridges to be manufactured to service standards, using crimped-in bullets with cannelures. Tests showed that this resulted in a small loss of accuracy but it would be several years before this requirement was relaxed. The contract that year went to Winchester (WRA Co 2 10). Winchester won again in 1911 (WRA Co 2 11). No matches were held in 1912, and U.S. Cartridge Co. won again in 1913 (USC Co 3 13). This proved to be the last year of commercial contracts and all subsequent National Match ammunition was manufactured by Frankford Arsenal.
At the outbreak of World War I the United States remained neutral, but the hostilities soon led to a reduction or cancellation of most competitive shooting and match ammunition production. There were no matches in 1914. In 1915 and 1916, Frankford Arsenal produced special lots of regular 1906 ball ammunition that were designated for limited National Match use (FA ? 15 and FA ? 16). There were no matches in 1917 and only limited matches were held in 1918 using standard war-quality ammunition. 1919 saw the resumption of cartridge production for the National Matches, albeit nothing more than selected lots of service ammunition (FA 19). 1919 was also the first use of the FA 70 priming compound and the last year of the flat base, 150 grain, cupronickel M1906 bullets in competition. A new phase in the development of the Cal .30 National Match ammunition was about to begin.
At the end of WW I the Army had huge stockpiles of service ammunition on hand and the manufacture of new ammunition could not be justified - except for the National Matches. Thus, the matches became the testing ground in a continuing effort to improve competition cartridges in particular and military ammunition in general. Innovations and experiments with cases, bullets, powders, and primers would be the norm rather than the exception.
Except for a few local and regional events, most matches were cancelled from 1941 through 1952. When the full National Match program resumed at Camp Perry in 1953, there was no standard for match ammunition. One lot with the M1 Type bullet was loaded for slow fire matches, but for the most part, selected lots of M2 Ball were issued for the next four years (FA 53, TW 54, FA 54 and FA 55). Coming from war-quality stocks, accuracy was not very good (3 inch to 5 inch 600 yard mean radius).
Cases Headstamped LC 78 NM
USMC G4 Ammunition
I have specifically listed those headstamps that a collector is most likely to encounter. But readers should be aware that others do exist. At least two lots of T291 cartridges with an LC 57 MATCH headstamp were manufactured and designated for practice. Additionally, Cal. .30 unprimed cases with LC NM headstamps and late 1970s dates, LC 78 NM, along with boxed M1 Type bullets, are well known. It’s believed that these components were furnished to the Army Marksmanship Unit (AMU) and the Director of Civilian Marksmanship (DCM) for sale to shooters wishing to hand load cartridges for use in matches. Turning to the 7.62 MM, International match cartridges from 1958, 1959 and 1960 also carry the MATCH headstamp but they have no National Match association.
The National Matches are not the only high-power rifle tournaments held in the U.S. or overseas. Formal shooting competitions at the longer distances have been held for more than 150 years. Most are civilian and private or quasi-public in organization. In the past, U.S. military rifle teams and individuals participated in many of these events using arms and ammunition supplied by the Government. Between 1900 and 1960, Frankford Arsenal produced thousands of rounds of special match ammunition for Olympic, Palma, Pan American, and other International matches. Headstamps usually reflect the particular shooting discipline for which they were intended. The major ammunition manufacturers such as Winchester and Remington competed for government contracts into the mid 1920s and continue to produce special match ammunition, some of it hand loaded, to this day. Another U. S. Government entity, the Army Marksmanship Unit, created in 1956, produces both match grade rifles and ammunition for use by service teams and individuals that participate in both the National Matches and other events around the world. Describing these many and varied special match cartridges is far beyond the scope of this article and I leave that for someone else.
This article opened with a description of the lack of financial aid and political support for competition shooting and it ends on the same sad note. In 1996, public law reorganized the NBPRP and DCM into the Corporation for the Promotion of Rifle Practice and Firearms Safety (CPRPFS) and the Civilian Marksmanship Program (CMP). Now a public corporation, CPRPFS maintains only a minor relationship with the Department of the Army and reimburses the U.S. Government for all costs incurred in transferring government arms and ammunition to civilians. With little public interest and with no Federal appropriations to depend upon, program emphasis has shifted from the traditional National Matches to “serving youth through gun safety and marksmanship activities that encourage personal growth and build life skills.” Supported almost exclusively by the National Rifle Association and thousands of shooters, the National Matches will go on but it’s doubtful if we’ll see another Government cartridge with a National Match headstamp.
[I have shamelessly borrowed from the following references. Since most of the information is very objective, it was not easy to keep from crossing the line into plagiarism. After all, how many ways are there to describe a bullet or a headstamp? I also depended heavily on my own collection and notes from 50 years of competitive shooting, and remembrances of other shooters that I know. But, any errors or omissions are mine alone. And finally, an article such as this opens the writer to the double risk of including too much information, or too little. I hope I have struck a comfortable balance. rm]
Hackley, Woodin, Scranton - History of Modern U.S. Military Small Arms Ammunition, 1967-78
Hatcher, Major General Julian S. - Hatcher’s Notebook, 1947
Lewis, B.R. - The Cal. .30 Cartridge in Match Competition, 1969
Punnett, Chris - .30-06, 1997
Rocketto, Hap - A Short History of National Match Rifle Ammunition, 1995
Sharpe, Philip B. - Complete Guide To Handloading, 1937