This article is part of Sinclair Int’l Step-By-Step Reloading Series. Most of the products mentioned in this article are sold through Brownells.com.
by Roy Hill, Brownells/Sinclair Copywriter
Making your own precision handloads is a meticulous journey with many steps, many important matters to consider, and many sets of measurements to calculate. For those who pursue the perfect group, the highest score, the really long accurate shot, the rewards more than outweigh the effort. Choosing the right cases, deburring the flash holes, making the primer pockets uniform, trimming the cases, and lubricating them are all familiar – and critical – steps along the journey. And now that your brass preparation is complete, you are at last ready to start running the cases through your press and fill them with primers, powder, and bullets. The very first die the brass encounters is the sizing die. You insert the case, work the press’s lever to return the case to its correct pre-fired dimensions – and the journey continues.
There are three types of sizing dies to think about: neck, full-length, and small base. All three have specific benefits and potential drawbacks, and you should choose the type of die you use by thinking very carefully about what kind of shooting you plan to do with your handloads. No matter which type you select, most sizing dies will also punch out the old spent primer with some sort of decapper assembly that uses a hardened steel rod. Many types of sizing dies use an expander ball inside the die to make sure the neck of the case will accommodate a bullet after being sized. With some size dies, the expanders are easily removable and interchangeable, letting you get exactly the neck tension you want. When sizing cases (neck of full-length), rifle cases always need lube.
Neck-Sizing Dies Neck-sizing dies resize only the neck of the case. The benefit of sizing only the neck is that the brass is “worked” very little, reducing the amount of changes to the brss. [We recommend full-length sizing for all applications after the first couple of firings, and semi-auto brass should be full-length sized every time!] Sinclair recommends that neck-sized-only cartridges should not be used any in other rifle besides the one they were originally fired from [unless they are also FL-sized], or in any action other than a bolt-action.
Full-Length Sizing Dies
Full-length sizing dies resize the full length of the case, not just the neck. Full-length sizing helps create handloads that will function in any rifle, not just the one from which the cases were originally fired. The potential downside of full-length sizing is that it may shorten case life because it works the brass more than neck sizing. But it’s possible to “tune” today’s full-length sizing dies so they barely work the brass at all, as this article by Sinclair Reloading Tech Ron Dague shows.
Illustration Shows How a Full-Length Sizing Die Works
Another way to reap the benefits of full-length sizing is to use Redding’s full-length bushing dies, which size the full length of the case but use a system of interchangeable bushings that enable you give the case neck the bare minimum of resizing needed. To see how finely adjustable bushing dies are, and how they resize the case while fully supported, CLICK HERE for Video. The neck bushing helps you precisely control the neck tension to help increase the consistency and accuracy of your handloads.
Small Base Dies
A Small Base Die is another type of full-length sizing die, but one that is typically used when reloading for semi-automatic rifles, like the AR-15, M14, or AR-style .308 rifles. (It may also work well for bolt guns that need extra sizing on the lower section of the case.) A small base die works exactly like a full-length sizing die, only it compresses the brass just a bit more, usually about .001″ more, and may even push the case shoulder back just a hair. Small base dies give that extra bit of compression to the brass to help make sure the case will properly extract from a semi-automatic firearm. The upside is that you get handloads that should work flawlessly in your semi-automatic. The downside is case life may be shortened as compared to brass used only in one bolt-action rifle, because the brass is worked more.
Shoulder Bump Gauges
A handy tool for setting up your full-length sizing dies as close as possible to your rifle’s chamber is a shoulder bump gauge. The bump gauge lets you resize the case as little as possible, to extend case life and help your handloads fit your rifle almost like a neck-sized only die. You use deprimed cases fired in your rifle and bump gauge inserts to help you set up the die so it resizes the case only about .001″ to .004″, depending on what type of rifle you’re shooting.
Video shows how to use a shoulder bump gauge to set up your full-length dies
Article Find by EdLongrange. We welcome reader submissions
There are many products used successfully for case lubrication for case sizing. And for neck-turning a variety of lubricants are favored. The video above explains the basics of case lubrication with die wax, and spray lubricants. Below we mention three products that have proven very effective. For cases that have a close fit to your chamber via custom FL dies, Ballistol works well and is easy to apply and remove. For neck-turning, some of our Forum members have had great success with some automotive lubricants.
Three Good Lubricants You May Not Have Tried Before If you’re using a body die or a full-length sizing die, try using Ballistol (in the aerosol can) as a lube. It works GREAT without the tacky or gooey residue left by most case lubes. It will also clean off carbon residues on the neck as you lube the case. Just spray a little on a cotton patch (or your fingertips) and wipe each case before you run it up into the die. If you are using a steel neck bushing, be sure to wipe the neck as well. You can usually do a half-dozen BR-sized cases before you need to re-apply Ballistol on the patch. Ballistol is non-toxic, bio-degradeable, and will not harm your skin. It is very slippery, but can easily be removed with a rag or paper towel. Try it–you may retire your One-Shot. Ballistol can also be used to protect wood stocks.
Note, for heavy case-forming or necking up case necks, we still recommend a thicker lubricant, such as Imperial Die Wax. But for normal case sizing, after your neck has been expanded, Ballistol will do the job, and you won’t need to tumble the brass afterwards. All you need is a very thin layer of Ballistol, and this easily wipes off with a paper towel.
For Neck-Turning, Try STP Blend or Assembly Lube
For lubing the neck-turning tool mandrel while turning case necks, many folks use a blend of STP® Oil Treatment and Mobil 1 lube. Chuckw2 reports: “Try STP and Mobile 1 Synthetic oil in a 50/50 mixture. Very slick, you will need to tumble your cases after turning.” STP is a very thick lubricant, that flows and clings almost like honey. Jason reports the STP blend comes off easily in an ultra-sound bath, using a bit of detergent. At many retailers, STP is also available in a convenient 7-ounce tube, so you don’t have to buy a large bottle.
Another even cheaper option is assembly lubricant. For turning his case necks, RStreich uses assembly lube from an auto parts store. He notes: “The brand I have is reddish in color and kind of sticky like honey. It’s far better than the Imperial die wax I was using before.” There are a variety of types, both with and without moly additive, and you can select the viscosity you prefer if you sample a few brands. Be sure to clean out any lube residue from the inside of your necks when you have completed your neck-turning.
The USAMU has published a “how-to” article about bullet sorting. While many of us may sort bullets by base-to-ogive length (and/or weight), the USAMU story explores the “how and why” of sorting bullets by Overall Length (OAL). Read the article highlights below, and make your own decision as to whether OAL sorting is worth the time and effort. Bryan Litz of Applied Ballistics says that sorting by OAL is not a bad idea, but base-to-ogive bullet sorting probably represents a better investment of your time.
Bullet Sorting by Overall Length
We’d like to share a specialized handloading technique which we’ve long found beneficial to our long-range (600 yards and beyond) accuracy. Sorting of bullets for extreme long range (LR) accuracy is not difficult to do, but some background in theory is needed.
Here at USAMU’s Handloading Shop, we only sort individual bullets for the most demanding Long-Range applications and important competitions. Only the most accurate rifles and shooters can fully exploit the benefits of this technique. The basic sorting process involves measuring the Overall Length (OAL) of the bullets, and grouping them in 0.001″ increments. It’s not unusual to find lots of match bullets that vary as much as 0.015″-0.020″ in length throughout the lot, although lots with much less variation are seen as well. Even in bullet lots with 0.015″ OAL variation, the bullet base-to-ogive length will show much less variation. Hence, our basic sort is by bullet OAL. One obvious benefit of sorting is easily seen in the attached photo. The few bullets that are VERY different from the average are culled out, reducing probable fliers.
How does one know what OAL increments to use when sorting? The answer is simple. As each lot of bullets is unique in its OAL distribution, it’s best to sample your bullet lot and see how they are distributed. In the attached photo, you will see a set of loading trays with a strip of masking tape running along the bottom. Each vertical row of holes is numbered in 0.001″ increments corresponding to the bullets’ OAL. A digital caliper makes this task much easier. As each bullet is measured, it is placed in the line of holes for its’ OAL, and gradually, a roughly bell-shaped curve begins to form.
Note that near the center, bullets are much more plentiful than near the edges. At the extreme edges, there are a few that differ markedly from the average, and these make great chronograph or sighting-in fodder. We recommend using a sample of 200 bullets from your lot, and 300 is even better. Some bullet lots are very consistent, with a tall, narrow band of highly-uniform bullets clustered together over just a few thousandths spread. Other lots will show a long, relatively flat curve (less uniform), and you may also see curves with 2 or more “spikes” separated by several 0.001″ OAL increments.
Bullet Sorting — OAL vs. Base-to-Ogive vs. Weight
Expert advice from Bryan Litz, Applied Ballistics
I’m often asked what is a the best measure to sort bullets by, and the answer (to this and many other questions in ballistics) is: it depends.
Choosing to sort by overall length (OAL), base to ogive (BTO), bearing surface, weight, etc. can get overwhelming. Shooters typically look for something they can measure, which shows a variation and sort by that. It’s common for dimensional variations to correlate. For example, bullets which are longer in OAL are typically also shorter in BTO, and have longer noses. All these are symptoms of a bullet that was pushed a little further into the pointing die, or possibly had more than average lube while being swaged. So in essence, if you sort by BTO, you’re measuring one symptom which can indicate a pattern in the bullets shape.
So, the question still stands — what should you measure? You’ll always see more variation in OAL than BTO, so it’s easier to sort by OAL. But sometimes the bullet tips can be jagged and have small burrs which can be misleading. Measuring BTO will result in a lower spread, but is a more direct measure of bullet uniformity.
Then there’s the question of; how much variation is too much, or, how many bins should you sort into? Shooters who see 0.025” variation in BTO may choose to sort into 5 bins of 0.005”. But if you have only 0.005” variation in the box, you’ll still sort into 5 bins of 0.001”. What’s correct? You have to shoot to know. Live fire testing will answer more questions, and answer them more decisively than any amount of discussion on the subject. The test I recommend is to identify bullets on the extreme short end of the spectrum, and some on the extreme long end. Load at least 10 rounds of each, and take turns shooting 5-shot groups with them. If there is a difference, it will be evident. The results of the testing will answer your question of: should I sort based on X, Y, or Z?”
You can read more discussions on this and other similar subjects in our Accurateshooter.com Shooters’ Forum. Here’s a link to a thread discussing bullet sorting: Bullet Sorting Thread
Neck-sizing dies resize only the neck of the case. The benefit of sizing only the neck is that the brass is “worked” very little, reducing the amount of changes to the brss. [We recommend full-length sizing for all applications after the first couple of firings, and semi-auto brass should be full-length sized every time!] Sinclair recommends that neck-sized-only cartridges should not be used any in other rifle besides the one they were originally fired from [unless they are also FL-sized], or in any action other than a bolt-action.
If you’re using a body die or a full-length sizing die, try using Ballistol (in the aerosol can) as a lube. It works GREAT without the tacky or gooey residue left by most case lubes. It will also clean off carbon residues on the neck as you lube the case. Just spray a little on a cotton patch (or your fingertips) and wipe each case before you run it up into the die. If you are using a steel neck bushing, be sure to wipe the neck as well. You can usually do a half-dozen BR-sized cases before you need to re-apply Ballistol on the patch. Ballistol is non-toxic, bio-degradeable, and will not harm your skin. It is very slippery, but can easily be removed with a rag or paper towel. Try it–you may retire your One-Shot. Ballistol can also be used to protect wood stocks.
For Neck-Turning, Try STP Blend or Assembly Lube
Another even cheaper option is assembly lubricant. For turning his case necks, RStreich uses assembly lube from an auto parts store. He notes: “The brand I have is reddish in color and kind of sticky like honey. It’s far better than the Imperial die wax I was using before.” There are a variety of types, both with and without moly additive, and you can select the viscosity you prefer if you sample a few brands. Be sure to clean out any lube residue from the inside of your necks when you have completed your neck-turning.
