Have you ever expanded a .22 or 6mm cartridge all the way up to .30-caliber? If so, you know this can be a difficult procedure that stresses the case necks and neck-shoulder junction. A significant neck-size expansion done in one big jump can increase run-out, cause doughnuts, or worse yet, even split the brass. Therefore you want to proceed in increments, increasing the neck diameter in stages. One smart way to do that is to use a Progressive Press. This article explains how…
The most successful short-range brenchrest-for-score cartridge is the 30 BR. That cartridge, as well as 30 BR variants such as the 30 BRX, all start with the 6mmBR Norma parent cartridge, typically with Lapua 6mmBR brass. To get a nice 30 BR case you want to expand in stages, increasing the inside neck diameter incrementally from .243 to .308.
Darrell Jones of DJ’s Brass Service creates thousands of 30 BR cases each year. He has found a clever way to speed up the process — Darrell uses a Progressive Press. He runs his 6BR brass through four (4) separate Hornady neck-sizing dies with expander mandrels. First there is a .257 die, followed by .264 (6.5mm), .284 (7mm), and then .308. Then a fifth and final K&M die provides one last, slight expansion so the newly-fashioned 30 BR cases perfectly fit the arbor of Darrell’s neck-turning tool.
So to repeat, the case starts as .243 (6mm), then moves in up stages .257, .264, .284, and .308, with a final “finishing” step prior to neck-turning. You can see the expansion in this video, which starts with 6mmBR brass that was first hydro-formed to 6 BRX:
Watch 6mm Cases Expanded to 30-Caliber (6BRX to 30 BRX)
For this demo video, Darrell expands just one case at a time. However, he can also put multiple cases in the progressive — one per station. This takes a little more effort, Darrell says, but the results are still excellent. Darrell tells us: “I do put multiple cases in the progressive to save time. The results are the same — I just wanted to show a single-step process and how it reduces run-out by not stressing the shoulder with one big expansion from 6mm straight to 30 caliber. Doing the operation in multiple stages avoids binds and helps keep the shoulders concentric.”
This same multi-stage procedure can be use to expand other cartridge types. For example you could take .221 Fireball brass in stages up to .308 to create 300 Blackout brass.
Darrell uses caliber-specific, Hornady neck-sizing-only dies with elliptical expanders. Darrell tells us: “The Hornady elliptical expander has a reduced bearing surface that puts less strain on the brass when expanding the necks to the next size.” The fitting at the bottom of the die is the Lock-N-Load die bushing that allows fast die changes.
These particular cases used in the video were first hydro-formed to 6BRX then expanded to 30 BRX before neck turning. DJ’s Brass offers hydro-forming for many popular wildcat cartridges such as 6 PPC, 6mm Dasher, and .284 Shehane.
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With the recent IBS 100/200 Group Nationals in Pennsylvania, we thought our readers might like to learn more about the short-range Benchrest game. Seeing the tiny groups 6 PPC aces produce, it’s easy to think the precision is all about the equipment. But there is a lot more involved. A talented human still has to watch the flags, run the gun properly, and tune his loads for the conditions. Here are some tips from one of the world’s best benchresters, Charles Huckeba.
Texan Charles Huckeba was the top individual shooter at the 2013 World Benchrest Championships (WBC) held near Sydney Australia in October 2013. In this video, 2013 WBC Two-Gun Overall winner Charles shoots a 1/8th MOA group at 200 yards — “a little bitty dot” as a fellow Team USA shooter observes. That’s impressive. If you can describe Huckeba’s style in a nutshell it would be “smooth, consistent, and rapid but not hurried”.
Charles also employed some unusual hardware. In the video, take a close look at the joystick on the Farley Coaxial front rest. There’s no knob at the end. In its place is a small, wood ammo caddy. Charles removed the standard knob from the handle of his Farley rest and replaced it with a home-made wood block that holds cartridges for the record target. The 10.5-lb Light Varmint rifle is chambered in 6PPC with a BAT Machine Action and a composite wood and carbon-fiber stock.
Watch Charles Huckeba Shoot 1/8 MOA, 200-yard group at World Benchrest Championships
Here is the actual 200-yard, 5-shot group Charles shot in the video. Photo (by Stuart Elliot) taken through the lens of Huckeba’s 50X March scope (reticle has 1/16th MOA Dot).
Analyzing the Fine Points — What Makes Huckeba So Good
Short-range benchrest shooter Boyd Allen saw some interesting things in Huckeba’s WBC performance, as captured on video. Boyd noticed Huckeba’s smooth gun-handling and efficient loading. But Boyd also spied some interesting equipment, including an innovative joystick “handle-caddy”.
1. Low Friction Bags — When Huckeba slid his rifle, there was very little apparent friction. The front bag features the new 3M material (ScotchLite) on the sliding surfaces. The rear Protektor bag has ears of the same low-friction material.
2. Pause Before Chambering — While he was watching the flags and deciding when to start firing, Charles kept his first round in the action, but out of the barrel’s chamber, probably so as not to heat the cartridge and change the round’s point of impact.
3. Ammo Caddy on Joystick Arm – Charles shoots a Right Bolt/Left Port action, so he pulls his rounds with his left hand. Note that Huckeba’s record rounds rest in a small, wood ammo caddy attached to the end of the joystick shaft. Look carefully, you’ll see the wood ammo block in place of the normal black ball at the end of the joystick. That allows Charles to pull shots with the absolute minimum of hand movement. Ingenious! Huckeba is very fast, with a great economy of motion. I believe that because his ammo was literally at hand, Charles was better able to keep his focus on aiming and the flags.
4. Smooth-Cycling BAT Action — Note how smoothly Huckeba’s action operates. When Charles lifts the bolt handle (to extract a round and cock the firing pin), this does not disturb the rifle. Likewise, as he closes the bolt, the gun doesn’t wobble. The smooth action allows Charles to hold point of aim even when shooting relatively quickly. Huckeba’s BAT action is chrome-moly steel. Some shooters believe this metal makes for a smoother action than stainless steel or aluminum.
5. Long-Wheelbase Stock — The wood and carbon fiber stock is light, long, and stiff. Yet, importantly, the stock is also well-damped. The longer-than-average stock length (with extended forearm) seems to help the gun track well without jumping or rocking. The longer forearm allows a longer “wheelbase”, effectively shifting the weight distribution rearward (less weight on the front, more weight on the rear). This places a greater share of the gun’s weight on the rear bag, as compared to a more conventional benchrest stock. Huckeba’s stock, built by Bob Scoville, is at the cutting edge of short-range benchrest design. Its light-weight balsa wood and carbon fiber construction provides a combination of stiffness and vibration damping that allows its relatively long fore-end to be fully utilized to increase the weight on the rear bag (always an issue with 10.5-pound rifles).
To learn more about this benchrest stock design, read the comments by stock-builder Bob Scoville in our PPC with Pedigree story in our Gun of the Week Archives. Bob observed:
“There is a lot more to the structure of the stocks than meets the eye. The carbon fiber skin with which I cover the stocks creates a light, tough exterior surface. However, this contributes very little to the overall performance of the stocks. The real strength and stiffness is the result of an internal beam utilizing balsa core/carbon fiber technology.
This type construction can be found in aircraft, race cars, powerboats, and sailboats. It is interesting to note, balsa has the highest strength to weight ratio of all woods and carbon fiber is one of the lowest stretch (modulus of elasticity) relative to weight of all materials. The marriage of these two materials is common in the high-performance world. Additionally, balsa is used commercially for vibration dampening and sound reduction.”
Video find by Boyd Allen. Video by Stuart Elliot of BRT Shooters Supply, Brisbane, Australia.
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Check out those five targets. The Aggregate (average) of all five targets is a tiny 0.0840 inches! These were shot by Gary Ocock at 100 yards in a California benchrest match on August 6, 2017. Though Gary’s 0.0840 Agg beats existing records, this was not a “sanctioned” match, so Gary’s killer Agg will NOT be submitted for IBS or NBRSA records. So, sadly, the Agg won’t appear in the record books, but this remains a spectacular, verified feat of rifle accuracy, accomplished in competition.
The argument can be made that this is the Most Accurate Gun Ever Built. As far as we can determine, no one has ever shot a smaller 5-target Agg anywhere, at any time.
The Unlimited Benchrest Record That Will Never Be (Official)
Report by Boyd Allen
Gary Ocock’s stunning unlimited Aggregate is beyond amazing. That’s an average of five, 5-shot groups of .0840. Shot under sanctioned match rules, but at an unsanctioned 100-yard fun match, this Aggregate is well under the current 100-yard official records of the IBS (.1386), and the NBRSA (.1242). The fourth of the five groups measured a minuscule .018, less than half the size of the existing NBRSA Unlimited record of .049 (also shot by Gary). Check it out:
When the top 15 shooters all post teen Aggs, conditions must be pretty favorable. However there were some light switchy winds — Gary said that he shot better in the left to right condition.
GUN SPECIFICATIONS
Ocock’s red Jay Young Unlimited Railgun features one major difference from Young’s typical Railgun designs. The bottom of the barrel block is integral with the top (moving part), of the gun. The barrel is Ocock’s usual 1:13.5″-twist Krieger chambered for the 6 PPC. The BAT Neuvo action* is unusual in that its lugs are horizontal at lock-up instead of the usual vertical. With horizontal lugs, both lugs maintain contact with their abutments when the action is cocked. In the more normal configuration when cocked the top lug is forced off of its seat by a combination of the angle of the trigger cocking piece interface, the pressure of the striker spring, and bolt clearance at the rear of the action.
LOAD SPECIFICATIONS
Gary shot this remarkable Agg with well-used brass, Vihtavuori N133 powder, and self-made 66gr BT bullets** seated at “jam”. This amazing Agg was shot on the second day of a 2-day Unlimited Benchrest match. On Day 1 Gary had experimented with various loads using both surplus IMR 8208 and Vihtavuori N133, but was not satisfied with the results. For his first group on Day 2, Gary tried a light load of N133. After seeing the result, however, he decided to go to the other extreme — a super stout N133 load — with the same powder. As you can see, Gary’s willingness to experiment paid off.
Notably, Gary used light neck tension. Ocock found that for these bullets and this barrel, light neck tension worked best (contrary to “normal” N133 benchrest practice). Ocock used a bushing that only produces .001″ difference between the diameters of sized and loaded case necks.
Comment on Ocock’s Achievement
Congratulations to Gary Ocock for superb shooting (and smart loading). Even though the match was not sanctioned (so the Agg will never be a record), Ocock has raised the bar very high, and given us a new standard of ultimate accuracy.
Though this 0.0840 Aggregate and 0.018 group will never go into the record group, they are still noteworthy. There’s virtually no doubt that they would have survived inspection by any record committee. Except for the lack of fixed backers, an IBS requirement (for detecting cross-fires), all other conditions were met for an officially-sanctioned match.
*The new BAT Neuvo actions are the result of a collaboration between Dwight Scott, and Bruce Thom, featuring Dwight’s ideas and BAT’s proven manufacturing expertise.
** Ocock shot his own, boat-tail match bullets, made with George Ulrich-crafted dies using Hood cores. Although he said that it had been a while since he had weighed any, his best guess was that they weigh something around 66.5 grains.
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IBS 31st Annual Memorial Match at Union County Sportsmen’s Club, Weikert, PA Reported by Jeff Stover, IBS President
The “Boop Shoot” is traditionally held on Mother’s Day in May, but this year it was moved to June due to a club conflict. No matter, as 63 shooters showed up on June 10th and 11th, 2017 to compete at one of the best benchrest ranges in the country. “Weikert” is nestled in a narrow valley in pastoral central Pennsylvania and has a wide following since the IBS Nationals have been held there a number of times.
The 2-Gun Aggregate represents “all the marbles” — the overall win for a weekend of Short Range Group shooting. Accuracy gunsmith Dave Bruno won the 2-Gun with a .2606 Agg shooting his 6PPC built on a Borden action in a Roy Hunter stock. On Dave’s heels was Al Auman, shooting a Goodling-built 6PPC BAT. In third place was Paul Mitchell with his BAT 3-Lug in a Scarborough stock built by Dwight Scott. The 2-Gun Aggregate is the combined average group size for 20 targets total, 10 each for both the Light Varmint (10.5-lb) and Heavy Varmint (13.5-lb) classes, with shooting at both 100 and 200 yards. Despite the class distinctions based solely on rifle weight, a vast majority of shooters opt for a 10.5-lb rifle for the entire course of fire. You get a lot of shooting at an IBS Registered Group match.
Two-Gun Overall Winner Dave Bruno (center) flanked by second place Al Auman (right) and third place Paul Mitchell (left).
The Tailwind from Hell
The real story of this match was the shooting conditions. For the entire weekend, there was a tail wind. When the wind blows hard, a pure tailwind is favored by many veteran shooters as velocity changes are less apparent on the target compared to a pure crosswind where pickups and letups can be mapped on the record target of a less-than-observant trigger puller. At this match, it was a tailwind from hell. The over-the-shoulder wind veered from red (right to left) to green (left to right) as quickly as it took you to read this sentence. The point of impact in the extremes could cause groups of 1.5 inches at 200 yards. It was one of those shoots where posting a .824” 200-yard group could move you up in the standings. Normally shooting an “eight” would assure a “bottom of the pile” finish.
Sunday morning saw that nefarious tailwind doing its dirty work once again, but it was not quite as bad as the afternoon would turn out to be. The tailwind’s impact, however, could be seen in the fact that the Heavy Varmint 200-yard winner was upstate NY shooter, Jim Miller with a .2817 (200-yard Aggregates are recorded in MOA, so Jim’s average group at 200 yards was .563”). He was the only competitor in the “twos”. Bob White shot well but his .3012 was not enough.
Scott Miller ready to pull the trigger on the firing line…
Dave Bruno Dominates Light Varmint 200
Light Varmint 200 was shot after lunch on Sunday. The winds had picked up while the shooters were enjoying burgers and hot dogs from the range house. This last Aggregate was the climax of the entire weekend. Two-gun winner Dave Bruno set the stage for his overall win by shooting as if he were from another planet. He was on fire with a .2388 Aggregate. Next was Bob Brushingham with a .3024. That is a difference of .0636” in average group size, or about 1/16th of an inch. A sixteenth is not much in most things, but in short range benchrest it is a chasm that Evel Knievel would not dare to test. Most Aggregates in benchrest are won and lost by a few thousands, or even ten-thousands of an inch. Dave blew out the field with his singular performance. When asked what condition he shot, Dave said “the tailwind” — go figure.
Yes, 100-yard was also contested. Back in the day, a “Teen Agg” (an aggregate of targets under .200”) was usually shot in perfect, or mild, readable conditions. The level of shooting in recent years, however, has seen Teen Aggs shot in tough conditions. The aforementioned tailwind prevailed on Saturday too, but was just a bit less nasty.
Loading at the range remains important in the Benchrest for Group discipline. In a Special Report below, IBS President Jeff Stover explains how loading methods (and hardware) have evolved over the years.
Pat Hurley checking his aim (notice bolt is out).
Two Gun Overall
1. Dave Bruno: .2604
2. Al Auman: .2727
3. Paul Mitchell: .2776
4. Bob Brushingham: .2851
5. Kent Harshman: .2969
Heavy Varmint Grand
1. Jim Miller: .2582
2. Bob White: .2622
3. Allen Arnette: .2706
Light Varmint Grand
1. Dave Bruno: .2375
2. Al Auman: .2717
3. Paul Mitchell: .2770
Light Varmint 100 was won by veteran Howie Levy (he started shooting in 1968!) with a .1794. He was not alone below .2, as Dale Boop was close at .1848. He was shooting Norma 201 to boot. This powder was the ticket to small 6PPC groups in the 1980s, but has been little seen for many years.
More Teen Aggs were shot in the Heavy Varmint relays. Benchrest Hall of Fame shooter Allen Arnette recorded a tiny .1686. On the podium with Allen were Howie Levy with a .1808 and Willie Bauer who shot a .1980.
Light Varmint Trophy Winners (L to R): Hensley, Boop, Auman, Brushingham, Francis, and Bruno.
Memorial Shoot Is a Family Affair
The 2017 Annual Boop Memorial Shoot ran like clockwork, as usual, and once again the success of this annual shoot can be attributed to the Trutt and Boop families. Mark Trutt serves as range officer extraordinaire. Dale Boop is match director while his mother, Linda, handles the administrative and scoring chores. Target crew honcho Steve Dodge, once again, ensured a rapid and accurate changing of the target.
NOTE: It has yet to be determined whether 2018 Memorial Match will be on Mother’s Day or in June.
Loading at the Range — Then and Now
In benchrest shooting for group, loading at the range has been de rigueur for decades. In the Score discipline, preloading is usually the custom. The main reason is that, in Score competition, only one Aggregate (warm-up match and five record targets) per day is usually shot. That would be less than 50 shots, assuming a few sighter shots. Also, the 30BR, the dominant Score cartridge, is amenable to pre-loading.
By contrast, the Group discipline includes 21 targets (two warm-ups and twenty record targets) over a weekend, usually shot with 6PPC-chambered rifles. Many times, the 6PPC shooters may tweak their loads through the day given changing atmospheric conditions or simply trying to find the correct tune to “dot up”. This term, “Dot up”, means the shots are essentially going through the same hole, or closely so.
Loading at the range was a bit different when benchrest competition was in its infancy. The 1951 book, Modern Accuracy by Bob Wallack, is the best of the early benchrest books. Copies can be found, from time to time, on eBay or Alibris. It is a fascinating survey of benchrest as it existed more than six decades ago. There’s even coverage of a controversial target that was argued over at the time. In it, there is a photo of Wallack using the rear bumper of a car at the bench to clamp his reloading tools. Things have come a long way compared to the range loading set-ups of modern shooters. Here you can see Bob Wallack way back in 1950:
Modern loading bench set-ups shown in this Boop Memorial Match Report belong to top shooters Howie Levy, Bob Hamister, and Kent Harshman.
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Most of us assume that if we weigh our powder carefully (down to the tenth of a grain or less) we can achieve a uniform powder fill from case to case in our handloads. Weighing does ensure that the weight of the propellant in each case is the same, but is the column of powder the same by volume each time? “Not necessarily” is the answer. An interesting experiment by our friend Boyd Allen demonstrates that the manner in which you place kernels in the case can make a significant difference in the height of the powder column within the brass case.
Using a Gempro 250 scale, Boyd measured exactly 30.6 grains of Vihtavuori N-133 powder. He then inserted this powder in the same cartridge case multiple times. (The case has a fired primer in place.) But here is the key — Boyd used various filling techniques. He did a slow fill, and a fast fill, and he also experimented with tapping and drop tubes. What Boyd discovered was that you can start with the exact same weight of powder (in fact the very same set of kernels), yet end up with vary different fill heights, depending on how you drop the kernels into the case. Look at the photos. Despite variations in lighting, the photos show the same 30.6 grains of powder, placed in the same cartridge, with four different methods.
Using funnels with long drop tubes packs kernels more tightly, creating a shorter powder column. That allows you to get more propellant (by weight) into the case.
Boyd Explains the Procedure Used for his Experiment.
EDITOR’s NOTE: So there is no misunderstanding, Boyd started with a weighed 30.6 grain charge. This identical charge was used for ALL four fills. After a fill the powder was dumped from the case into a pan which was then used for the next fill technique to be tried. So, the powder weight was constant. Indeed the exact same kernels (of constant weight and number) were used for each fill.
Boyd writes: “I used the same powder for all fills, 30.6 gr. on a GemPro 250 checked more than once. All fills employed the same RCBS green transparent plastic funnel. The fast drop with the funnel only overflowed when it was removed from the case neck, and 15 granules of powder fell on the white paper that the case was sitting on. The fast-funnel-only drop with tapping, was done with the funnel in place and the case and funnel in one hand, while tapping the case body with the index finger hard, many times (about 20 fast double taps). My idea here was to “max out” the potential of this tapping technique.
The slow drop with the funnel and 10″-long .22 cal. Harrell’s Precision drop tube, was done by holding the scale pan over the funnel and tapping the spout of the pan repeatedly on the inside of the funnel about 1/3 down from the top, with the scale pan tilted just enough so that the powder will just flow. Many taps were involved, again, to max out the technique.
Again, to be clear, after each case filling, the powder was poured from the case back into the scale pan carefully. You may notice the similarity between the fast drop with the drop tube, and the funnel only with tapping. Although I did not photograph it, fast tube drop and tapping (combined) improved on tapping alone, but only to about half as far down the neck as the slow with drop tube. Due to the endless possible permutations, I picked four and left it at that.
I believe that I can make the rough judgment that the scale pan funnel and drop tube technique, which involved a longer drop period, and probably less velocity at the top of the tube, left more room in the top of the case neck than the slow drop from the measure with the same drop tube. You have both pictures, so you can make the comparison.” — Boyd
Does Powder Column Height Variance Make a Difference?
Boyd’s experiment proves pretty conclusively that the method of dropping a given weight of powder can affect the height of the powder column in the case and the degree of powder compression (when a bullet is seated). He showed this to be true even when the exact same set of kernels (of constant weight) was used in repetitive loadings. This raises some interesting questions:
1. Will subsequent cartridge transport and handling cause the powder to settle so the variances in powder column height are diminished?
2. If significant inconsistencies in powder column height remain at time of firing, will the difference in fill level hurt accuracy, or result in a higher extreme spread in velocity?
3. Is there any advantage (beyond increased effective case capacity) for a tight (low level) fill vs. a loose (high level) fill?
We don’t know the answer to these follow up questions. This Editor guesses that, if we tested low-fill-height rounds vs. high-fill-height rounds (all with same true fill quantity by weight), we might see meaningful differences in average velocity. I would also guess that if you fired 10 rounds that exhibited quite a difference in powder column heights, you might see a higher ES/SD than if you shot 10 rounds loaded with a very consistent powder column height (either high or low). But further testing is needed to determine if these predictions are true.
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The Cactus Classic is a prestigious benchrest competition held every year in Phoenix, Arizona. On March 16-20, many of the nation’s top short-range benchresters came to Ben Avery to vie for glory and prizes. There were some impressive performances at this year’s Cactus Classic, hosted by the Arizona Benchrest Shooters. Top Gun was Larry Costa who won the Two-Gun Grand Aggregate as well as the Light Varmint (LV) 200-yard Agg. Lou Murdica (shown below) won the Heavy Varmint (HV) 200-yard Aggregate. At the shorter range, Larry Baggett won the Heavy Varmint 100-yard Aggregate and Gary Bristow won the Light Varmint 100-yard Agg. For full results, click the link below. To see hundreds of high-rez photos from the match, visit the Berger Bullets Flickr Photo Gallery.
We first ran this story a couple seasons back. Since they we’ve received many questions about this gun, so we thought we’d give readers another chance to learn about this truly innovative, switch-barrel “convertible” rifle. This gun works for both short-range and long-range benchrest matches.
You interested in a really wild, innovative bench gun that can shoot both short-range and long-range matches? Check out Seb Lambang’s latest “do-it-all” rifle. It’s a switch-barrel rifle combining two very different chamberings: 6 PPC and .284 Winchester. With that caliber combo, Seb’s covered from 100 yards (LV/HV mode) all the way out to 1000 (LR Light Gun mode). But the dual chambering is not the rifle’s only trick feature. Exploiting the new long-range benchrest rules, Seb has fitted a 3″-wide, flat rear metal keel to the buttstock. That counter-balances his 30″-long 7mm barrel, improves tracking, and adds stability. Seb built the stock and smithing was done by Australian gunsmith David Kerr.
Detachable Hammerhead Wing Section Plus Fat-Bottom Keel
To further reduce torque and improve tracking, the stock features an 8″-wide, detachable fore-end fixture. This “hammerhead” fore-end section has extended “wings” on both sides, making the rifle super-stable. The hammerhead unit can be removed, leaving the stock 3″ wide for use in registered benchrest matches where 3″ is the maximum width. The photos below show Seb’s gun in .284 Win Long-Range (LR) Light Gun mode.
Have a good look at the photos below — this may be one of the most noteworthy target strings we’ve ever published. What you can see is the effect of barrel tuner position on point of impact (POI). You can clearly see that the tuner position alters the up/down POI location in a predictable fashion.
This remarkable 15-shot sequence was shot by French benchrester Pascal Fischbach using his 6 PPC fitted with a CG (Carlito Gonzales) action and a Bukys barrel tuner.
Pascal reports: “After [bullet] seating and load validation, I put the Bukys tuner on, screwing it out 10 turns. According to Carlito, the CG’s super stiff action-to-barrel fit gives a faster vibration modulus that is detrimental below 10 turns [position of the tuner].” Pascal’s procedure was to screw out the tuner 1/4 turn progressively from one shot to the next. He shot one bullet at each tuner position, with a total of 15 shots.
Left Half of Target Strip (shots with 1/4 rotation change of tuner in sequence)
Right Half of Target Strip (shots with 1/4 rotation change of tuner in sequence)
Pascal observed: “Note the point of impact displacement [from shot to shot] tracks clearly along a sinusoide (sine wave curve).” This is indeed notable and significant! This shows how the tuner’s ability to change barrel harmonics can alter the position of the muzzle as each bullet exits, resulting in a higher or lower POI. Pascal sent his results to Carlito Gonzales in Argentina for analysis.
Pascal poses this question to readers: “Guess which three positions Carlito recommends to try?”
Editor’s Note: While this target sequence clearly shows how tuner position can alter bullet point of impact, this, by itself, does not tell us which tuner position(s) are best for accuracy. That will require further multi-shot group testing, involving careful experimentation with tuner position (and powder charge weights). But for those folks who doubt that a tuner can make a difference on a short, fat barrel, just take another look at the photos. The up/down changes are undeniable, and noteworthy in the wave pattern they follow.
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Responding to customer requests, PMA Tool is now offering carbide expander mandrels in popular calibers. These carbide mandrels are listed as .22, .24, .26, .28, and .30 calibers, but they are sized for popular chamberings in .223, .243 (6mm), .264 (6.5mm), .284 (7mm), and .308 (7.62mm). PMA’s new carbide expander mandrels will cost $56.95 per item.
PMA’s tool-makers tell us: “Over the past several months we have received many requests to make expanding mandrels from carbide. Due to this popular demand we are now offering expanding mandrels from carbide. Carbide reduces galling and scratching both on the inside of the case neck and the mandrel itself. We still recommend the use of lubricant when expanding case necks to make the operation easier. These mandrels are ground from a 3/8” solid carbide blank and sized properly to expand case necks, preparing them for neck-turning. They can also be used to iron out dings and flat spots on new brass not destined to be neck turned, preparing them for loading and bullet seating.”
PMA Dual Taper Non-Carbide Expanders are Just $8.95
PMA also makes regular steel expander mandrels at a much lower price — $8.95. These regular Expanding Mandrels are designed to fit both the 21st Century Shooting and Sinclair Expander Dies. PMA states: “Our mandrels are longer than other expanding mandrels and feature a special dual taper which expands both on the up and down stroke of the press to more uniformly expand and straighten case necks.” These regular expanders are offered for all popular calibers, from .17 all the way to .338.
PMA Specialized Necking-Up Mandrels for 30 BR and 6 PPC
Last but not least, PMA makes specialized “long-taper” expanders designed to expand 6mmBR brass to 30 BR brass, or expand 220 Russian brass to 6mm (for the 6 PPC). Priced at $9.95, these handy, effective tools make it easy to neck-up your brass for 30BR or 6 PPC.
PMA explains: “So you want to make 30BR brass quick? Here’s the mandrel for you. A while back, while forming some 30BR brass for a customer’s rifle we noticed that after necking 6mm up to 30cal the neck fit on the turning mandrel was a lot tighter than we wanted. Regardless of how many steps we took to get there we had to run the case necks over the final expander repeatedly to get the fit right. After that experience we decided to set out and make a mandrel with optimum taper and diameter to neck 6mm up to 30 caliber in one step. We think is the best way to expand the necks of 6BR Lapua brass [for the 30 BR]. Remember to always use plenty of lubricant when necking.”
Product Tip from EdLongrange. We welcome reader submissions.
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Jackie Schmidt, posting on Benchrest Central, observed that there may have been some production changes with Lapua 220 Russian brass. This brass is commonly used as the parent case for fire-forming 6 PPC cases. The newer 220 Russian brass has slightly thicker neckwalls, and, according to Jackie, the new brass is more consistent in overall neckwall thickness.
Jackie writes: “I have not made any new PPC cases in a while. But I finally used up all of my older 220 Russian brass, and just bought 500 new cases, in the blue plastic boxes. The necks are thicker. By at least .0008 (eight ten-thousandths). That is right at .0015 on diameter. I am getting neck-wall thickness of .0142″ on the old cases, .0150″ on the new cases. I [fire-formed] two cases, and seated a Flat Base Ultra bullet in each. The old case, with a seated bullet and non-neck-turned case, measures .2708″ average. By contrast, the new case, with a seated bullet in an unturned neck, measures .2722″ average. That is, on average, about .0015 difference in the diameter of a seated round.”
“Anybody else notice this? I guess the main reason I did the measuring is that I am thinking of having a ‘no-neck turn’ reamer ground. With this new brass, .0274″ would be the minimum. The new brass is a tad better in overall [neck]-wall thickness variation.” — Jackie
What does Lapua say? We’ve sent inquiries to Lapua’s USA tech representatives. We hope to have a response soon.
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