December 28th, 2014

Tips for Loading Straighter Ammo with Less Run-Out

This article originally appeared in Sinclair Intl’s Reloading Press Blog, which has been merged into the Gun Tech Section on Sinclair’s website, www.SinclairIntl.com

Steps to Minimize Bullet Run-Out

Poor bullet run-out can cause poor and inconsistent accuracy, and variations in bullet velocities. The truer the loaded round, the more consistent your results will be on paper and across the chronograph.

Sinclair Concentricity gaugeMeasuring Concentricity
We all know that low run-out is the goal. But how can you tell if your run-out is high or low? Run-out is generally measured in thousandths of an inch with a concentricity gauge. There are many concentricity gauges to choose from that work well. Some work on loaded rounds only, some have a bullet straightening feature, and a few work on both loaded rounds and empty cases for checking case neck concentricity. The tool of choice for the Sinclair Reloading Tech Staff is the Sinclair Concentricity Gauge (Part # 09-175).

This tool is a mainstay on my bench, and it is used about as much as I use my reloading press! The tool uses two sets of bearings that are set on lateral, length-adjustable anodized aluminum blocks to accommodate cartridges from .221 Fireball-sized cases up to .50 BMG. The indicator is set on a height adjustable swiveling base on a stand that can be used for checking bullet or case neck run-out. The adjustable blocks ride aligned in a precision-milled slot. The entire set up is on an anodized base plate that gives excellent support during the process that is crucial to operation and accuracy. Basically the operation consists of placing a loaded round (for checking bullet run-out) or an empty case (for case run-out) on the bearings with the indicator end touching the chosen point to be measured. The case is easily spun with one finger as the indicator measures the amount of run-out. Once this process has been done a few times it is a fast and accurate means of measurement. In terms of indicator type being used, whether dial or digital, I actually prefer a standard dial indicator over the digital type. My reason for this choice is that you can see the needle jump when run-out is present. I believe this to be easier and faster than looking at digital numbers while measuring. In the video below, Sinclair’s Bill Gravatt shows how to use the Sinclair Concentricity Gauge correctly.

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Sizing Steps to Minimize Run-Out
One of the most common steps in the reloading process that contributes to bullet run-out occurs is the sizing operation. If improper techniques are used or there are issues with the sizing die set up, a once perfectly concentric case can become out of whack. By using the proper dies for your application, properly setting up the die/shell holder or floating the de-capping/expander assembly, you can eliminate problems before they happen.

Sinclair Concentricity gaugeMany of us on the technical staff choose the Redding Type-S series of dies. These are full-Length or neck sizing dies that utilize a removable/changeable neck bushing (sold separately) to size the neck according to your application. These dies are machined with true precision and quality in mind. The Type-S dies come with a standard de-capping assembly with a caliber-specific expander ball in place. In addition to this an undersized retainer to hold the de-capping pin is included with the die. In my experience with these dies I use the standard expander ball with new, unfired brass on the initial re-size. I will then use the undersized retainer in place of the expander ball with brass that has been fired. I have found this step crucial in my reloading regiment to minimize bullet run out. The use of the expander ball can cause a few thousandths of run-out when the case is being pulled back out of the sizing die. With the undersized retainer in place the only thing that touches the neck of the case in sizing is the bushing. If you prefer to use an expander ball, Redding offers caliber specific carbide floating expander balls that fit on the de-capping rod. This free floating expander ball will self center on the case neck, and reduce the amount of run-out that can be caused by a standard expander ball.

When setting up a Type-S sizing die, set the neck bushing into the die with the numbers facing down toward the body of the die. Tighten the de-capping assembly until it contacts the bushing and then back it off ¼ of a turn. This allows the bushing to free float in the die. You should be able to hear the bushing rattle if you shake the die. Having the bushing free floating self centers the neck, and again minimizes any run-out that can occur.

If you prefer other brands of sizing dies there are a few tricks that people use to minimize run-out as well. Many reloaders claim that the use of an O-ring at the base of the de-capping assembly lock nut will float the assembly and help self center during sizing. Another trick that has been used is to remove the retaining pin on the shell holder slot on the press ram, and use an O-ring in its place to hold the shell holder in place. This allows the shell holder to self center during sizing as well.

Seating Steps to Minimize Run-Out
Run-out issues can arise during the bullet seating process. To reduce run-out during seating, use a high-quality die with a sliding sleeve. The sliding sleeve perfectly aligns the case with the bullet to be seated. Good examples of these dies are the Redding Competition Micrometer bullet seating dies, Forster Ultra Seaters, or RCBS Competition Seating dies. All of these dies utilize a micrometer top to precisely set seating depth. They are all very high quality dies that have tight tolerances to maximize bullet straightness during seating.

We receive many questions about seating long pointed bullets such as the Berger VLD or Hornady A-Max. One problem that the reloader faces with longer bullets is that they are so long that the standard seating stem is not machined deep enough to contact these bullets properly. The point of the bullet “bottoms out” in the stem and the result is off-center seating and/or rings and dents on the bullet nose. If you plan on using such bullets, you should purchase a “VLD” style seating stem, which is cut to accommodate the longer bullets. The use of this stem results in truer seating of the bullet without leaving a ring or marring the tip of the bullet.

Besides using a traditional press and threaded seating die, another great way to get a true bullet seat is by using an arbor press and Wilson chamber-type seating die. These dies are cut to very tight tolerances and have proven themselves as the main choice for bench rest enthusiasts. The design of the die positively aligns the case with the bullet as they are both captured by the die before the bullet is pushed straight into the case by the stem. These seating dies are available with the standard seating cap and stem or an additional micrometer top can be added for precise adjustment. Wilson also offers a stainless seating die with an integral micrometer seating head.

Finally another trick used by many in the seating process is to turn the case while the bullet is being seated. Some people claim this will keep things straight. What they do is raise the ram in increments while seating and rotate the case in the shellholder in increments of 90 degrees from the original starting while the bullet is being seated. Personally I have tried this and have seen no significant difference at all. However you may be the judge of this one. It makes sense, and maybe I should try this a little more before I rule it out.

After the Rounds Are Loaded — Batch Sorting by Concentricity Levels
No matter how meticulous you are, and no matter how good your components and tools are, run-out will still show up. Reloaders can drive themselves crazy trying to make each and every loaded round a true “0” in run-out. You will still see some minimal amount no matter what you do. Set yourself a standard of maximum allowable run-out for your loads. For instance for my Long Range 600- and 1000-yard F-Class loads I like to see .002” or less. I average .0015” and see a few in the range up to .004”. I spin each loaded round on my Sinclair Concentricity Gauge and sort them by run-out. Those that run over .002” I use for sighters or practice. Though achieving zero run-out (on every round) isn’t possible, minimizing run-out can definitely help your performance. Not only will your loads shoot better but you will have one less thing to worry about when you are lining up the sights on the target.

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April 17th, 2012

Don’t Over-Chamfer Your Necks — Bullet Damage Can Result

Shaving bullet jackets is a problem reloaders encounter from time to time. It can be caused by excessive neck tension, burrs on the case mouth, or over-aggressive chamfering that leaves a ragged edge on the case mouth. Larry Medler discovered some rounds where the bullet jackets were getting shaved. Diagnosing the problem, he found that this was caused by his outside neck chamfer. He was using a powered screwdriver to rotate the case, and over-cutting plus tool chatter was causing the case neck to roll inwards. This created a thin, sharp edge that actually cut into the bullet jacket as the bullet was being seated.

bullet jacket shavingneck chamfering

Larry has a Load Force 250 measuring instrument that records the dynamic bullet seating force and displays the results on a computer screen. Larry noted that spikes in seating force were associated with the cases where the bullets were shaved. Inspecting the cases, Larry realized what was happening. Chamfering the outside after doing the inside allowed his tools to cut too much. Combined with tool chatter, this actually created a sharp, ragged edge that rolled inward towards the bullet: “I discovered I had rolled the case mouth rim inward while deburring the outer edge. When deburring the case mouth on the outside edge, every now and then I could hear some tool chatter. The effects of this chatter really show in the picture.”

bullet seating force

The above chart shows the dynamic bullet seating force for the bullet with the shaved jacket. Note the large initial force used to cut and scratch the bullet outer surfaces. The final seating force of 47 pounds is just before the Wilson Seating Die bottoms out and the force on the load cell jumps. The chart below shows normal bullet seating force.

bullet seating force

As a fix, Larry decided to reverse the neck deburring operations. Now he deburrs the outside first. This reduces tool chatter and prevents the edge from rolling over, because the neck thickness has not been thinned by inside chamfering. While Larry uses a powered screwdriver to speed his case processing, the lesson applies to those who chamfer manually as well–do the outside first and never overcut.

Remember, you simply want to remove burrs and create a slight chamfer. You don’t want to thin the brass significantly at the case mouth. This is why it is important to be very careful when using a deep-angle cutter such as the K&M inside neck chamferer. Click HERE to read Larry’s full report on neck chamfering, with more details on use of the Load Force 250 measuring instrument. Using device such as this, or a K&M arbor press equipped with a seating force gauge, will help you diagnose problems with your neck tension and reloading procedures.

Permalink Bullets, Brass, Ammo, Tech Tip 7 Comments »
October 29th, 2010

New Precision Powder Funnel from 21st Century

21st Century Funnel21st Century Shooting has just introduced what may be the most advanced powder funnel on the market. It has everything you could want. The top section is precision ground and polished for a smooth flow. The center has a see-through tube so you can watch the progress of your powder dropping into the case. At the bottom of each funnel is a precision brass collar insert that allows the funnel to stand on the case without tipping off. The collars are offered in nine, caliber-specific sizes: 17cal, 20cal, 22cal, 30cal, 5mm, 5.5mm, 6mm, 6.5mm, and 7mm. In addition, 21st Century offers custom-milled collar inserts fitted precisely to your cases. That way you can get a perfect fit on neck-turned brass. Just mic your casenecks and 21st Century will craft a custom insert.

Each funnel, with one caliber-specific insert, costs $21.75. Additional standard inserts are $5.75. Call 260-273-9909 for pricing on custom inserts.

Permalink Gear Review, New Product No Comments »
May 19th, 2010

New Annealing Machines from Ballistics Edge Mfg.

model 200 annealing machineForum member and long-range shooter Jerry Brandon has launched a new company, Ballistics Edge Mfg., which produces cartridge annealing machines for use by home reloaders. Brandon, a talented designer and fabricator, first tried annealing to maintain the quality of his own match brass. Brandon then built and tested a series of prototype annealing machines, working with a variety of brass sizes. Now Ballistics Edge Mfg. offers a full line of four annealing machines: the manually-operated Model 200 ($250), the motorized twin-torch Model 300 ($345), the motorized triple-torch Model 350 ($395), and the motorized Model 400 ($475), a beautifully-machined carousel design.

Brandon’s most versatile machine, and the one he recommends for annealing both normal- and magnum-sized cases, is the Model 350. Like the Model 300, the Model 350 features all-metal construction and motorized case transport. The Model 350 uses three torches rather than the Model 300’s two. The triple-torch system does a better job heating the large-diameter necks on .338, .416 and .50-caliber cases. The triple-torch design also ensures fast, uniform heating of the case-necks on smaller cases. The video below shows the Model 350 in action, annealing jumbo-sized .50 BMG cases.

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model 200 annealing machineFor PPC, 6mmBR, and .308-sized cases, you can use the Model 200, the Model 300, or the Model 400. The Model 200 is a simple, one-at-a-time annealer that works remarkably well using a sliding arm. Simply slide the case into the flame, then slide it out after the required dwell time. For the average reloader, the Model 200 may be more than adequate. If, however, you plan to anneal hundreds of cases a week, you may want to consider the beautifully-machined Model 400 carousel, which will anneal 100 cases in less than 15 minutes. The Model 400 features both .308-size and magnum/ultra magnum-size holes to accept both .47X and .56X diameter cases. Just choose the correct size hole and adjust the torch height to match your case. The .75″-thick shell-plate top acts as a heat-sink to protect the lower case body. View the Model 400 carousel annealer in the video below.

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Ballistics Edge Website Offers Good Technical Advice on Annealing
Anyone interested in learning about cartridge annealing should visit www.AnnealingMachines.com, Jerry Brandon’s website. There you’ll find a helpful, authoritative discussion of annealing, including the all-important factors of time and temperature. As Brandon observes, much MISinformation about annealing can be found. Brandon will set you straight. Read Brandon’s How to Anneal article and you can avoid making costly (and potentially dangerous) mistakes, whether you anneal manually or use an annealing machine. In the video below, Jerry Brandon reviews the features of Ballistics Edge annealing machines. He also provides some good, basic advice for shooters who are looking to try their hand at annealing for the first time.

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Permalink Bullets, Brass, Ammo, New Product, Reloading 1 Comment »