For some applications, we prefer a non-bushing FL die over a bushing die. Shown here are three Forster full-length sizing dies, with necks honed to three different dimensions: 0.265″, 0.266″, and 0.267″.
The Honed Full-Length Sizing Die Option
There are many good options in full-length (FL) sizing dies. Most precision hand-loaders prefer FL dies with neck bushings. These let you adjust the “grip” on your bullet by using larger or smaller bushings. FL bushing dies are available from Whidden Gunworks, Forster, Redding and other makers.
Conventional, non-bushing full-length sizing dies can create ultra-accurate ammo with very low run-out. But many conventional non-bushing FL dies have an undersized neck diameter so you end up with excess neck tension, and you work the brass excessively.
There is another effective option, one that promises extremely low run-out. The honed FL die is a full-length sizing die that has the necked honed to provide a precise fit to the case-neck. When done right, honed FL dies produce extremely straight ammo — as there are no issues with bushing alignment (or bushings that are not perfectly concentric). This Editor owns honed dies from Forster, Redding, and Whidden Gunworks. They all perform extremely well, delivering match ammunition with extremely low run-out measured with a 21st Century Concentricity Gauge.
In one of the most popular articles we’ve ever published, Bugholes from Bipod, California shooter “Froggy” explained why he prefers honed dies for his tactical ammo.
Q: Do you FL size every time? Do you use custom dies?
Absolutely, I full length resize all of my brass every time I reload. And guess what? I’ve never had a feeding problem.
I do use a modified sizing die, without bushings. My FL resizing die has been custom-honed in the neck area to give .0015″ press fit on the bullet. I also put a slightly larger radius at the neck shoulder junction. I feel that this helps to seal the chamber. With this die, I get consistent neck tension every time–without bushings. Bushings are useful when you’re fishing around for a good load. But once you find the right amount of sizing for ideal neck tension, you can do this better with a customized FL die.
6.5 Guys Review Forster Honed Full-length Dies
The 6.5 Guys have reviewed honed FL sizing dies from Forster, explaining the pros and cons of this type of reloading die. They explained that, if you load a wide variety of bullets from different manufacturers, you many want to stick with a Bushing FL die. However, if you have settled on a particular bullet and found the “ideal” neck tension, then a honed die may make sense.
In this Gear Update, the 6.5 Guys discuss a service offered by Forster Products to custom hone the neck diameter of its full-length sizing dies to the customer’s specifications (to the thousandth). Whidden Gunworks has also crafted custom-honed FL dies for many customers, including this Editor.
The Tactical Rifle Shooters Facebook Group recently showcased tools used to measure case headspace before and after “bumping” the shoulder. After a case is fired, hand-loaders who full-length size their cases will typically bump the shoulders back anywhere from .001″ to .0035″, depending on the rifle and application. With our 6mmBR and Dasher cases we like about .0015″ bump.
You want the amount of case sizing and bump to be the same for all your brass. To ensure uniformity, it makes sense to measure your cases before and after the FL sizing process. When we have time, we check every case. Other folks will simply check the first 3-4 cases coming out of the FL sizing die to ensure the FL die setting is correct and delivering desired headspace/bump.
Whidden Gunworks Shoulder Bump Gauge
There are a variety of tools that can be used to measure shoulder bump. Our favorite is a special cartridge-specific bushing made by Whidden Gunworks. The Whidden Shoulder Bump Gauge enables you to adjust your sizing die to the desired measurement. The bump gauge is attached to your calipers with a set screw and determines the measurement from the base to the shoulder of the case. The photo below, from Tactical Rifle Shooters, shows the Whidden Bump Gauge for the .375 CheyTac cartridge.
Dave Manson Vertical Comparator with Dial Read-Out
Dave Manson states: “This tool was designed to make life easier for the advanced shooter and re-loader by allowing precise measurement of ammunition, case, and chamber headspace. With this information, the re-loader will be able to fine-tune clearances and fits between his ammunition and chamber, with resultant improvements in accuracy and case life.” The functions of the Manson Dial Cartridge Comparator are:
1. Measure headspace of factory or reloaded ammunition
2. Quantify chamber headspace by measuring headspace of a fired case
3. Ensure minimal shoulder set-back when setting up re-loading dies
4. Compare base-to-ogive length to ensure consistent bullet-to-rifling relationship.
In addition to the Dial Indicator and Stand, the $180.00 Dial Cartridge Comparator is supplied with multiple Datum Blocks of precise length and inside diameter (.3300″/.3750″/.4000″/.4375″). MORE INFO HERE.
Hornady L-N-L Headspace Comparator System
Hornady’s Lock-N-Load Headspace Comparator system is easy-to-use and handy. You can get a kit with Red bushing-holder body and 5 bushings for $43.99 at MidwayUSA. Hornady explains: “The Lock-N-Load® Headspace Comparator… gauge measures variations in brass before and after firing or re-sizing. It allows for headspace comparison between fire-formed brass and re-sized brass.” IMPORTANT: Hornady states: “To determine the proper bushing diameter for your cartridge, simply add the neck diameter and the shoulder diameter and divide that number by two. Use the bushing closest to that number.” Hornady offers seven: .188″, .240″, .330″, .350″, .375″, .400″, and .420″.
One tip — We have found the Hornady gauges may vary a little from unit to unit even with the same nominal size. If you have more than one gauge for the same cartridge, test each on your brass — you may then note a slight difference in your bump measurements. Mark one and use that consistently. There is also an Anvil Base Kit that mounts to the opposite blade on the caliper. This provides a more stable surface for the base of your case.
L.E. Wilson Case Gage Depth Micrometer
If you are looking for precise “bump” measurements without having to mess with calipers and clamp-on gauge blocks, you may want to consider the L.E. Wilson Case Gage Depth Micrometer (currently $140.00). This takes very precise, repeatable measurements, but you need to know your starting point. The manufacturer explains: “Every reloader should know exactly how much your Full Length Sizing Die is pushing back the shoulder. With the NEW Case Gage Depth Micrometer you can do just that! It has never been easier to measure you cases headspace before and after sizing. The Depth Mic allows you to slip the micrometer perfectly over the top of the Gage with your case inserted into the Gage and take a measurement. Micrometer has graduations of .001″. The Case Gage Depth Micrometer is set to a zero of .100″ on the scale at our factory. Because of differences in ‘feel’ and temperature, we include a the Gage Block for you to test Zero and to adjust if necessary.”
Pistol Brass Case DIY Bump Gauge
Last is a “field expedient” set-up if you do not have any of the comparator tools shown above. A sized .45 ACP case (or other suitable pistol case) can be used to measure shoulder bump. The mouth of the pistol case sits on the shoulder of your rifle cartridge brass.
Make sure the .45 ACP case is trimmed square and that it is round. We recommend you first run it through an expander, then size it, trim it and chamfer. Next, take the .45 ACP case and slip it over the neck of a fired, unsized rifle case with the primer removed. Align the two cases between the jaws of your calipers and note the length from rim to rim (See left photo below).
OK, now you have the length for a fired rifle case BEFORE sizing. Next, take a full-length sized rifle case (without primer) and do the same thing, placing the .45 ACP case over the neck of the FL-sized case (Right Photo). The difference between the two numbers is the amount of “bump” or set-back you are applying to the shoulder. Here the difference is .0015″. The amount of bump you need varies with your chamber and your load, but .0015-.002″ is a good initial setting.
Can you form a wildcat cartridge such as the 6 Dasher without expending primer, powders, and bullets? Absolutely. Using the hydro-forming method you can form improved cases in your workshop with no firing whatsoever, so there is no wear on your precious barrel. Watch this video to see how it’s done:
6 Dasher Case Hydro-Forming Demonstration:
Forum member Wes J. (aka P1ZombieKiller) has produced a helpful video showing how to form Dasher cases use the Hornady Hydraulic forming die kit. This includes a two-part die (body and piston), and a special shell holder. To form the case, you insert a primer in your virgin brass, top the case off with with a fluid (water or alcohol), then run the case up into the Hydro-forming die. A few stout whacks with a hammer and your case is 95% formed.
This same procedure can be accomplished with a Whidden Gunworks 6mm Dasher hydraulic form die. We like the Whidden hydro-forming die for its production quality and consistent results. This Whidden system works great according to our Forum members.
Hydro-Forming Procedure Step-by-Step:
1. Insert spent primer in new 6mmBR brass case.
2. Fill with water or alcohol (Wes prefers alcohol).
3. Wipe excess fluid off case.
4. Place case in special Hornady shell-holder (no primer hole).
5. Run case up into Hydraulic forming die.
6. Smack top piston of forming die 3-4 times with rubber mallet or dead-blow hammer.
7. Inspect case, re-fill and repeat if necessary.
8. Drain alcohol (or water) into container.
9. Remove primer (and save for re-use).
10. Blow-dry formed case. Inspect and measure formed case.
Wes achieves very uniform cartridge OALs with this method. He measured ten (10) hydro-formed 6 Dasher cases and got these results: two @ 1.536″; 2 @ 1.537″; and 6 @ 1.538″.
Three or Four Whacks Produces a 95%-Formed Case
With a Whidden or Hornady hydro-forming die, hydraulic pressure does the job of blowing out the shoulders of your improved case. The process is relatively simple. Place a spent primer in the bottom of a new piece of brass. Fill the case with water, and then slip it into a special Hornady shell-holder with no hole in the middle. Then you run the case up into the forming die. Now comes the fun part. You gently insert a plunger (hydraulic ram) from the top, and give it three or four stiff whacks with a mallet (or better yet, a dead-blow hammer). Remove the plunger and you have a 95% formed case, ready to load.
Special Shell-Holder
Hornady supplies a shell holder made specifically for the hydro die; there’s no hole in the bottom of it. Just insert a spent primer into the primer pocket and you’re ready to go. The spent primer, combined with the solid shell holder, keeps the water from seeping out of the primer pocket. The primer pushes out a little bit during this process, but it’s impossible for it to come out because of the way the shell holder is designed. The shell holder has a grove which allows the case to slide out of the shell holder even when the primer protrudes a bit.
For some applications, we prefer a non-bushing FL die over a bushing die. Shown here are three Forster full-length sizing dies, with necks honed to three different dimensions: 0.265″, 0.266″, and 0.267″.
The Honed Full-Length Sizing Die Option
There are many good options in full-length (FL) sizing dies. Most precision hand-loaders prefer FL dies with neck bushings. These let you adjust the “grip” on your bullet by using larger or smaller bushings. FL bushing dies are available from Whidden Gunworks, Forster, Redding and other makers.
Conventional, non-bushing full-length sizing dies can create ultra-accurate ammo with very low run-out. But many conventional non-bushing FL dies have an undersized neck diameter so you end up with excess neck tension, and you work the brass excessively.
There is another effective option, one that promises extremely low run-out. The honed FL die is a full-length sizing die that has the necked honed to provide a precise fit to the case-neck. When done right, honed FL dies produce extremely straight ammo — as there are no issues with bushing alignment (or bushings that are not perfectly concentric). This Editor owns honed dies from Forster, Redding, and Whidden Gunworks. They all perform extremely well, delivering match ammunition with extremely low run-out measured with a 21st Century Concentricity Gauge.
In one of the most popular articles we’ve ever published, Bugholes from Bipod, California shooter “Froggy” explained why he prefers honed dies for his tactical ammo.
Q: Do you FL size every time? Do you use custom dies?
Absolutely, I full length resize all of my brass every time I reload. And guess what? I’ve never had a feeding problem.
I do use a modified sizing die, without bushings. My FL resizing die has been custom-honed in the neck area to give .0015″ press fit on the bullet. I also put a slightly larger radius at the neck shoulder junction. I feel that this helps to seal the chamber. With this die, I get consistent neck tension every time–without bushings. Bushings are useful when you’re fishing around for a good load. But once you find the right amount of sizing for ideal neck tension, you can do this better with a customized FL die.
6.5 Guys Review Forster Honed Full-length Dies
The 6.5 Guys have reviewed honed FL sizing dies from Forster, explaining the pros and cons of this type of reloading die. They explained that, if you load a wide variety of bullets from different manufacturers, you many want to stick with a Bushing FL die. However, if you have settled on a particular bullet and found the “ideal” neck tension, then a honed die may make sense.
In this Gear Update, the 6.5 Guys discuss a service offered by Forster Products to custom hone the neck diameter of its full-length sizing dies to the customer’s specifications (to the thousandth). Whidden Gunworks also offers custom-honed FL dies.
This article is Copyright 2023 AccurateShooter.com. Any publication on another website is unauthorized and obligates monetary compensation and statutory damages.
Whidden Gunworks makes great sizing and seating dies. The Whidden full-length sizing die with neck bushing is very popular because it allows you to “tune” the neck tension by using different bushings, with larger or smaller inside diameters. In this video, John Whidden explains how to choose a the right bushing size for use with your neck-sizing and full-length sizing bushing dies.
For most applications, John suggest starting with the caliper-measured outside diameter of a loaded cartridge (with your choice of bullet), and then SUBTRACT about three thousandths. For example, if your loaded round mics at .333, then you would want to start with a 0.330 neck bushing. John notes, however, that you may want to experiment with bushings, going down a thousandth and up a thousandth. With thin In addition, as your brass ages and the necks harden, you may want to change your bushing size.
Quick Tip: Try Flipping Your Bushings
You may also want to experiment with “flipping” your neck bushings to alternate the side that first contacts the neck of the case. (One side of the bushing is usually marked with the size, while the other side is unmarked.) So try “number side up” as well as “number side down”.
Some folks believe that one side of the bushing may allow a smoother entry, and that this can enhance concentricity. Other people think they can get very slightly more or less neck tension depending on how the bushing is oriented. This is a subtle effect, but it costs nothing to experiment.
If one bushing orientation proves better you can mark the “up” side with nail polish so that you can always orient the bushing optimally. NOTE: We have confirmed that some bushings are actually made with a slight taper. In addition, bushings may get distorted slightly when the brand name and size is stamped. Therefore there IS a reason to try both orientations.
I have seen it time and time again, shooters on the line wrestling with their rifle trying to get the bolt closed while the wind is switching. They were too focused trying to get their bolt to close and getting their rifle settled back on the bags that they missed the wind switch. Bang… Eight! The straw that broke the camel’s back for me was at the 2017 Canadian Nationals. I was paired up with a young girl and she would try really hard to close the bolt on her rifle. The majority of the time she would get it to close, but often times she could not even get the round to chamber. She was focused on her rifle the entire time rather than on the conditions. When we completed our strings, she had five rounds that did not chamber our of 15! That is way too many!. I told her she needed to think about Full-length sizing with 0.002″ shoulder bump, or Controlled Full-length Sizing like I call it. I told her not to worry about losing accuracy. I told her that I full-length size all my rounds and asked if she noticed how smooth my bolt was and noticed my score. She said yes, they were both great!
Controlled Full-length Sizing Does NOT Harm Accuracy
I have found that Controlled Full-length Sizing does NOT hurt accuracy or shorten brass life. I find that I can focus much more on the conditions when I don’t have to think about chambering a round nor extracting it. It has become second nature. After firing, I keep my head welded to the stock, I open the bolt by placing my thumb on top of stock and rotating hand upwards. I reach in and retrieve spent case, place it back in ammo box, and pick up another loaded round and put in chamber. I verify conditions and when ready, I push the bolt in and close it with my index and middle finger.
With Controlled Full-length Sizing you “bump” the shoulder around .002″ for bolt guns.* Image courtesy Sinclair International which carries a variety of Full-length dies.
Whidden Full-Length Sizing Dies by AccurateShooter.com Editor
For proper full-length sizing, you want a quality die that’s a very good match to your chamber. For our project rifles we usually turn to Whidden Gunworks which offers both bushing and non-bushing FL dies. And if you want the hot new option, check out Whidden’s patent-pending, click-adjustable FL-sizing die. This gives instant, precise control over shoulder bump. It works great.
*With gas guns, such as the AR10, you may want to increase shoulder bump to .003″ or more. With some benchrest cartridges, .0015″ bump may prove optimal. But .002″ is a good starting point.
With the Whidden Click-Adjustable Sizer Dies, you can change shoulder bump by .001″ (one-thousandth) with a simple click. Fast. Easy. Precise.
As handloaders have become more aware of shoulder bump and proper adjustment of the sizer die in recent years, there has become a need for an easier way to adjust the sizer die properly. For most folks, with their conventional dies, it takes lengthy trial trial and error to get the shoulder setback correct. Anyone who has done this can attest that it can be a slow and annoying job.
Whidden Gunworks has solved the problem with the innovative Click Adjustable Sizer Die. Patent No: 10,393,488. This die and lock ring work together to give the user a clicking feel to the adjustment just like a high end rifle scope. Each click moves the shoulder bump exactly .001″ so you can easily find the exact shoulder bump that you desire.
The Click Adjustable option is available on Whidden Custom Sizer dies as well (7/8”-14 format dies only)! Included with the Click Adjustable Sizer Die is a Shoulder Bump Gauge. This gauge attaches to standard calipers and allows measurement from the case shoulder to the base. Using the Shoulder Bump Gauge with the Click Adjustable Sizer Die will make the proper sizer die setup easier than ever before.
Click-adjustable die sets are available with both bushing and non-bushing configurations. Along with these complete die sets, Whidden Gunworks offers a separate click-adjustable ring to use with existing dies. Priced at $58.99, the Whidden Click-Adjust Lock Ring represents a modest investment for a major gain in die ease-of-use and precision adjustability.
The Whidden Universal Click Adjustable Lock Ring you can instantly turn your sizer die into a Click Adjustable Die. This ring works with any 7/8 OD sizer of any brand with adjustable shoulder bump. Simple in design, the inner and outer ring can rotate independently of each other. Each click is metered in true 1 thousandths adjustment and has 0.100″ total available travel. These work great with nearly all sizing 7/8 OD sizing dies, and one verified purchaser noted: “Not only are they useful on reloading dies, but it’s the cat’s meow on the Giraud Power Trimmer Case Holders.”
Dillon Users Take Note: The Whidden Click Adjustable Sizing Die will not work with the Dillon 550 or 650 progressive reloading press systems. The Universal Click Adjustable Lock Ring is not compatible with the Dillon floating toolhead.
John Whidden is a 6-time National High Power Long Range Champion. He has also won major Palma matches in the USA and abroad. But John’s stellar marksmanship skills are not just limited to long range centerfire shooting. This month John added to his impressive list of shooting titles with a notable victory in the 2024 CMP Smallbore (.22 LR Rimfire) Championship match held at Camp Perry, Ohio.
In today’s Sunday GunDay story, John examines that CMP Championship match and the smallbore match rifle he used. This is a unique, one-of a kind rig, put together with a combination of premium components from multiple manufacturers. John’s ultra-accurate .22 LR rifle features a PQP 2500X action, Tec-Hro Fanatic stock, MullerWorks barrel, Uptagrafft Tuner/Bloop Tube, and Anschutz trigger. For different segments of the smallbore competition the rifle is fitted with iron sights or a Nightforce scope.
CMP Match Report — Whidden Wins Match with Final Shot
The 2024 National Smallbore Prone 6400 Aggregate Championship came down to millimeters. The event was part of the Civilian Marksmanship Program’s 2024 National Matches and was the culmination of four straight days of prone competition. Tight qualification matches saw the top three places separated by one point each, with John Whidden of Nashville, GA, leading the pack on the last leg of the match.
Whidden had been consistent throughout his entire National Matches appearance, having only dropped five points in the previous 15 rounds of the competition. His confidence continued as he took each shot. Then, unexpectedly, he pulled one left — just grazing the edge line of the 10-ring. An eye opener, to be sure.
Despite the close call, he pressed on. “A Prone 6400 Match is a marathon, and this, essentially, was a photo finish,” said Brad Donoho, CMP Smallbore Manager.
Whidden took his final shot, another 10. With a sigh of relief, John packed up his gear and walked off the firing line with a perfect score of 400 and the overall Open win in the Smallbore Prone 6400 Aggregate with a score of 6395-515X. “He finished out the match really strong”, Donoho said. “To see it all come down to the last shot was really incredible.”
Winning 2024 CMP Smallbore Prone Championship at Camp Perry
Report by John Whidden
The 2024 CMP Smallbore Prone National Championships are in the history books now. On the day before the match started, the CMP held a metric Dewar match. This was a bit of a warmup match and was well attended. The course of fire was 30 shots at 50 meters and 30 shots at 100 meters. I knew the match would be exciting as I got out of the car — the wind almost took the car door out of my hands! Yes, it was that kind of day.
Usually at the range, I can read the wind acceptably well, but there are occasionally some days when it just won’t come to me. The metric Dewar session was one of those days that I just couldn’t understand the wind indicators. I finished with a score of 575-24X which was below what I’d hoped for. I was feeling slapped around at this point!
Fortunately, the first day of the prone Championships was better. While still fairly windy, I found it much easier to read and finished up with 1599-103X leading the event. We shot iron sights for the first two days, and on day 2 Levi Clark shot the highest score and made up a point on my lead.
Days 3 and 4 are both shot with scopes on the gun. Usually with these scores, we see fewer points dropped. Shane Barnhart won day 3 with a blistering 1600-149X. Going into the last day I was only 1 point ahead and behind on X count. I knew with this tough group of shooters if I shot a 9 anywhere on day 4 I probably wouldn’t win it. I shot very carefully and tried to protect my points lead even if it meant giving up a few Xs along the way.
The day went well but I had a big scare on the next to the last shot. The wind picked up and I shot a 10.0 (these electronic targets will score in decimals) which is ALMOST a 9. I gathered myself for the last shot and felt my heart beating hard. I knew it had to be a good one because second place Nick Mowrer was breathing down my neck. Thankfully the shot stayed in the 10 Ring and I knew I had won the match.
Unique Rimfire Rifle with Premium Action, Stock, Barrel, & Tuner
The rifle I used for the match had just recently been built in our shop. Since opening the rimfire ammunition test range in May of 2024 we had the chance to observe some top-quality components in testing. After noting what was shooting really well, I decided to order a PQP 2500X action, a MullerWorks barrel, and a Uptagrafft Tuner/Bloop Tube. I had already purchased a Tec-Hro Fanatic aluminum stock suitable for the project and had an Anschutz trigger set aside.
MullerWorks has a highly respected standing for their barrels, especially in the rimfire community. I chose a MullerWorks 1:16″-twist barrel and finished it at 26″ OAL. I fitted a Tuner/Bloop Tube from Uptagrafft to the muzzle. This allows me to make the sight radius longer for iron sight matches and has a tuner integrated into the design.
The parts went together well. In the stock, I modified an action adapter that was intended to fit an Anschutz 54 into the Tec-Hro stock. I placed the action as far rearward in the stock as I could to make reaching the loading port easier. A benefit of the Anschutz trigger is that the trigger shoe is more forward than the Remington-type trigger, and this was a noticeable benefit in allowing the action to be mounted far back in the stock.
Call to Action-Maker about Fitting Anschutz Trigger
These PQP 2500X actions accept Remington pattern triggers but I use Anschutz triggers on all of my other prone guns. Because of familiarity I really wanted the Anschutz trigger on the new rifle. On the day before my action was to arrive I contacted Jerry Stiller who designed the action. I asked Jerry if the tang was long enough to retrofit an Anschutz trigger onto the action (Anschutz triggers are very large). He said he didn’t think it would fit. Well, things went well and the next evening I sent him a picture of my Anschutz trigger installed on the action. It has performed marvelously.
Once the rifle was all fitted and assembled, it was time to go to the test range. I shot through all of the ELEY and Lapua ammunition that we had available. One particular lot of ELEY Tenex and one lot of Lapua Center-X stood out as the winners. I shot several groups with each one and couldn’t determine a winner. Accuracy was excellent with group sizes averaging about 13.3mm (0.52″) outside to outside at 50 meters. The next evening I shot some more of each lot of ammunition and again neither ammo type was clearly better than the other. NOTE: 13.3 mm outside to outside is .303″ center to center.
Trying to break the ammunition tie, I decided to adjust the tuner on the third evening. I worked the tuner back and forth and arrived at the best setting. Up until now, I had shot the rifle with the tuner set as it arrived in the box, in this case setting number 500. On this particular rifle moving the tuner shrunk the group diameter by 4%. On some of my other rifles, I had seen a larger effect in the 14-15% range. I wasn’t unhappy though as the rifle was shooting well and importantly it was doing so very consistently.
When dry-fire training indoors, the rifle is fitted with a device on the end of the barrel that tracks barrel movement and shot location on a special electronic target. The device and target are sold together as the SCATT USB Dry-Fire Shooter Training System.
Secrets of a Rimfire Prone Champion — Whidden Wisdom 1. Shoot a High Volume of Ammo. There is really no substitute for rounds down range. The picture shows hundreds of spent cases — just a fraction of the several thousand rounds of ammo I shot from prone before the national events this summer.
2. Recognize the Difference between Training and Practicing. Training to me means that I have a defined goal that I’d like to achieve during that session. For example I may go shoot a match for training and my goal is to shoot all of my shots in the exact same wind condition and without making a sight adjustment for wind. This would help further my ability to recognize my desired wind condition.
3. Demand Top-level Accuracy from Your Rifle and Ammo. Often shooters are not objective enough about their testing and will excuse a bad shot with “I must have pulled that one” or similar comments. To win matches one needs reliable and durable accuracy across different temperatures and environmental conditions.
Major Benefits of Extensive Rimfire Ammunition Testing
Before the Championship at Camp Perry, I did significant rimfire ammunition testing, which proved very valuable. First I shot 10-round groups of all of the available lots. Next I shot 3 more 10-round groups of the lots that looked most promising. This is the same procedure we use for customer’s rifles when we test them. The worst of the initial 10 round groups was 25.4mm (1 inch) at 50 meters and the best was 12.4mm (0.49″) at 50 meters (measured outside edge to outside edge).
I want to illustrate the value of testing right here. Among the top ammunitions available one lot shot about half the diameter of a different lot. It’s just not possible to buy ammunition at random and expect the very best accuracy that way. The ammunition I chose averaged 13.3mm (0.52″) outside edge to edge at 50m across several groups. I decided to shoot the ELEY Tenex in the end. The performance of both ammunitions was equal but another of my rifles also shoots well with this lot of Tenex so that’s a bonus. Don’t think I didn’t also grab some of that Lapua Center-X and set it back for the right occasion!
Whidden Gunworks operates a state-of-the-art ammunition testing facility. You can visit the facility or ship your rifle to be tested with different lots of rimfire ammo. The Whidden facility features two testing lanes — one for testing ELEY ammo at 50 meters and a second for testing other brands (e.g. Lapua, SK, Norma, and RWS) at both 50 meters and 100 meters simultaneously, registering results for BOTH distances. For more info, visit Whiddengunworks.com/ammunition-testing.
Whidden Gunworks makes great sizing and seating dies. The Whidden full-length sizing die with neck bushing is very popular because it allows you to “tune” the neck tension by using different bushings, with larger or smaller inside diameters. In this video, John Whidden explains how to choose a the right bushing size for use with your neck-sizing and full-length sizing bushing dies.
For most applications, John suggest starting with the caliper-measured outside diameter of a loaded cartridge (with your choice of bullet), and then SUBTRACT about three thousandths. For example, if your loaded round mics at .333, then you would want to start with a 0.330 neck bushing. John notes, however, that you may want to experiment with bushings, going down a thousandth and up a thousandth. With thin In addition, as your brass ages and the necks harden, you may want to change your bushing size.
Quick Tip: Try Flipping Your Bushings
You may also want to experiment with “flipping” your neck bushings to alternate the side that first contacts the neck of the case. (One side of the bushing is usually marked with the size, while the other side is unmarked.) So try “number side up” as well as “number side down”.
Some folks believe that one side of the bushing may allow a smoother entry, and that this can enhance concentricity. Other people think they can get very slightly more or less neck tension depending on how the bushing is oriented. This is a subtle effect, but it costs nothing to experiment.
If one bushing orientation proves better you can mark the “up” side with nail polish so that you can always orient the bushing optimally. NOTE: We have confirmed that some bushings are actually made with a slight taper. In addition, bushings may get distorted slightly when the brand name and size is stamped. Therefore there IS a reason to try both orientations.
The Tactical Rifle Shooters Facebook Group recently showcased tools used to measure case headspace before and after “bumping” the shoulder. After a case is fired, hand-loaders who full-length size their cases will typically bump the shoulders back anywhere from .001″ to .0035″, depending on the rifle and application. With our 6mmBR and Dasher cases we like about .0015″ bump.
You want the amount of case sizing and bump to be the same for all your brass. To ensure uniformity, it makes sense to measure your cases before and after the FL sizing process. When we have time, we check every case. Other folks will simply check the first 3-4 cases coming out of the FL sizing die to ensure the FL die setting is correct and delivering desired headspace/bump.
1. Whidden Gunworks Shoulder Bump Gauge
There are a variety of tools that can be used to measure shoulder bump. Our favorite is a special cartridge-specific bushing made by Whidden Gunworks. The Whidden Shoulder Bump Gauge enables you to adjust your sizing die to the desired measurement. The bump gauge is attached to your calipers with a set screw and determines the measurement from the base to the shoulder of the case. The photo below, from Tactical Rifle Shooters, shows the Whidden Bump Gauge for the .375 CheyTac cartridge.
2. Dave Manson Vertical Comparator with Dial Read-Out
Dave Manson states: “This tool was designed to make life easier for the advanced shooter and re-loader by allowing precise measurement of ammunition, case, and chamber headspace. With this information, the re-loader will be able to fine-tune clearances and fits between his ammunition and chamber, with resultant improvements in accuracy and case life.” The functions of the Manson Comparator are:
1. Measure headspace of factory or reloaded ammunition
2. Quantify chamber headspace by measuring headspace of a fired case
3. Ensure minimal shoulder set-back when setting up re-loading dies
4. Compare base-to-ogive length to ensure consistent bullet-to-rifling relationship.
Hornady’s Lock-N-Load Headspace Comparator system is easy-to-use and handy. You can get a kit with Red bushing-holder body and 5 bushings for $39.99 at Midsouth. Hornady explains: “The Lock-N-Load® Headspace Comparator… gauge measures variations in brass before and after firing or re-sizing. It allows for headspace comparison between fire-formed brass and re-sized brass.” IMPORTANT: Hornady states: “To determine the proper bushing diameter for your cartridge, simply add the neck diameter and the shoulder diameter and divide that number by two. Use the bushing closest to that number.” Hornady offers five: .330″, .350″, .375″, .400″, and .420″.
One tip — We have found the Hornady gauges may vary a little from unit to unit even with the same nominal size. If you have more than one gauge for the same cartridge, test each on your brass — you may then note a slight difference in your bump measurements. Mark one and use that consistently. There is also an Anvil Base Kit that mounts to the opposite blade on the caliper. This provides a more stable surface for the base of your case.
4. L.E. Wilson Case Gage Depth Micrometer
If you are looking for precise “bump” measurements without having to mess with calipers and clamp-on gauge blocks, you may want to consider the L.E. Wilson Case Gage Depth Micrometer (currently $130.00). This takes very precise, repeatable measurements, but you need to know your starting point. The manufacturer explains: “Every reloader should know exactly how much your Full Length Sizing Die is pushing back the shoulder. With the NEW Case Gage Depth Micrometer you can do just that! It has never been easier to measure you cases headspace before and after sizing. The Depth Mic allows you to slip the micrometer perfectly over the top of the Gage with your case inserted into the Gage and take a measurement. Micrometer has graduations of .001″. The Case Gage Depth Micrometer is set to a zero of .100″ on the scale at our factory. Because of differences in ‘feel’ and temperature, we include a the Gage Block for you to test Zero and to adjust if necessary.”
5. Pistol Brass Case DIY Bump Gauge
Last is a “field expedient” set-up if you do not have any of the comparator tools shown above. A sized .45 ACP case (or other suitable pistol case) can be used to measure shoulder bump. The mouth of the pistol case sits on the shoulder of your rifle cartridge brass.
Make sure the .45 ACP case is trimmed square and that it is round. We recommend you first run it through an expander, then size it, trim it and chamfer. Next, take the .45 ACP case and slip it over the neck of a fired, unsized rifle case with the primer removed. Align the two cases between the jaws of your calipers and note the length from rim to rim (See left photo below).
OK, now you have the length for a fired rifle case BEFORE sizing. Next, take a full-length sized rifle case (without primer) and do the same thing, placing the .45 ACP case over the neck of the FL-sized case (Right Photo). The difference between the two numbers is the amount of “bump” or set-back you are applying to the shoulder. Here the difference is .0015″. The amount of bump you need varies with your chamber and your load, but .0015-.002″ is a good initial setting.
Hydro-Forming Procedure Step-by-Step:
Special Shell-Holder
Quick Tip: Try Flipping Your Bushings
Whidden had been consistent throughout his entire National Matches appearance, having only dropped five points in the previous 15 rounds of the competition. His confidence continued as he took each shot. Then, unexpectedly, he pulled one left — just grazing the edge line of the 10-ring. An eye opener, to be sure.
Quick Tip: Try Flipping Your Bushings
