Vertical stringing is a common problem that all precision shooters will face sooner or later. In addition to ammo inconsistencies, many other factors can cause vertical stringing. Accordingly, it’s important that you analyze your gun handling and bench set-up systematically.
EDITOR: Folks, READ THIS ARTICLE! You WILL benefit. There are some VERY important insights here. You’ll learn ways to set up your gun better, and check for various technical issues. That can save you time at the range and save you money spent on expensive bullets and powder.
In this article, Hall of Fame benchrest Shooter Speedy Gonzalez explains how to eliminate mechanical and gun-handling problems that cause vertical spread in your groups. Speedy’s article addresses the many human and the hardware factors that can cause vertical.
Speedy Gonzalez, noted shooter, gunsmith and member of the Benchrest Hall of Fame, offers these pearls of wisdom to help you eliminate vertical in your shot strings. Remember that vertical can result from myriad gear issues and gun-handling mistakes. Try to isolate one item at a time as you work to improve your groups.
BAGS and REST–VERY IMPORTANT
• Front Rest Wobble — You will get vertical if the top section of the front rest is loose. Unfortunately, a lot of rests have movement even when you tighten them as much as you can. This can cause unexplained shots.
• Rifle Angle — If the gun is not level, but rather angles down at muzzle end, the rifle will recoil up at butt-end, causing vertical. You may need to try different rear bags to get the set-up right.
• Front Bag Tension–Vertical can happen if the front sand bag grips the fore-arm too tightly. If, when you pull the rifle back by hand, the fore-arm feels like it is stuck in the bag, then the front bag’s grip is too tight. Your rifle should move in evenly and smoothly in the sand bags, not jerk or chatter when you pull the gun back by hand.
• Sandbag Fill — A front sandbag that is too hard can induce vertical. Personally, I’ve have never had a rifle that will shoot consistently with a rock-hard front sandbag. It always causes vertical or other unexplained shots.
• Bag Ears — If the channel between the Rear Bag’s ears is not in line with the barrel, but is twisted left or right, this can affect recoil and vertical consistency. And take note — if the bag is off-axis quite a bit, you can also get horizontal stringing.
• Reliability — ALL your bench equipment must work flawlessly. If it doesn’t, get it fixed or get rid of it. We need all our attention on wind flags.
GUN HANDLING and BENCH TECHNIQUE
• Be Consistent — You can get vertical if your bench technique is not the same every shot. One common problem is putting your shoulder against the stock for one shot and not the next.
• Free Recoil — Free recoil shooters should be sure their rifle hits their shoulder squarely on recoil, not on the edge of their shoulder or the side of their arm.
• Head Position — Learn to keep your head down and follow-through after each shot. Stay relaxed and hold your position after breaking the shot.
• Eyes — Learn to shoot with both eyes open so you can see more of the conditions.
• Last Shot Laziness — If the 5th shot is a regular problem, you may be guilty of what I call “wishing the last shot in”. This is a very common mistake. We just aim, pull the trigger, and do not worry about the wind flags. Note that in the photo above, the 5th shot was the highest in the group–probably because of fatigue or lack of concentration.
• Last Shot Low — I hear a lot of discussion about low shots in a group and apparently this occurs a lot on the 5th shot. If your 5th shot that goes out most of the time, you can bet you are doing something at the bench.
• Seating — When possible, bring your own stool so that you can sit comfortably, at a consistent height, every time you shoot.
LOAD TUNING
• Find the Sweet Spot — A load that is too light or too heavy can cause vertical problems. When you’ve tuned the load right, you should see a reduction in vertical. Even 0.1 grain may make a difference, as will small changes in seating depth.
• Primers — If you’re getting vertical, and everything else looks fine, try another brand of primers. And remove the carbon from the primer pockets so the primers seat uniformly every time.
• Case Prep — When you chamfer the inside of your case necks make sure they are smooth enough that they don’t peel jacket material off when you seat the bullet. Bullets with J4 Jackets (like Bergers) and Lapua Scenar bullets seem more prone to jacket scratching or tearing than Sierra bullets.
• Shell Holders — Keep shell holders clean, in both your press and priming tool. I have seen so much dirt/crud in shell holders that the cases end up get sized crooked because the rim is not square to the die.
• Water in Cases — I see people walking around with case necks turned up in the loading block. A lot of the time there is condensation dropping from the roof of your loading area. If one drop of water gets in a case you are in trouble. How many times have you had a bad low shot when it has been raining and you have been walking around with your cases turned up in your block?
MECHANICAL and HARDWARE ISSUES
• Barrel Weight — A lot of rifles are muzzle-heavy. Some rifles have too heavy a barrel and this causes vertical, especially when shooting free recoil. Basically the gun wants to tip forward. The remedy is to trim or flute the barrel, or add weight in the rear (if you can stay within weight limits).
• Unbalanced Rifle — If the rifle is not balanced, it does not recoil straight, and it will jump in the bags. If the rifle is built properly this will not happen. Clay Spencer calls this “recoil balancing”, and he uses dual scales (front and rear) to ensure the rifle recoils properly.
• Firing Pin — A number of firing-pin issues can cause vertical. First, a firing pin spring that is either too weak or too strong will induce vertical problems. If you think this is the problem change springs and see what happens. Second, a firing pin that is not seated correctly in the bolt (in the cocked position) will cause poor ignition. Take the bolt out of rifle and look in the firing pin hole. If you cannot see the entire end of firing pin it has come out of the hole. Lastly, a firing pin dragging in bolt or shroud can cause vertical. Listen to the sound when you dry fire. If you don’t hear the same sound each shot, something is wrong.
• Trigger — A trigger sear with excessive spring load can cause problems. To diagnose, with an UNLOADED gun, hold the trigger in firing position and push down on sear with your thumb. If it is hard to push down, this will cause vertical problems.
• Stock Flex — Some stocks are very flexible. This can cause vertical. There are ways to stiffen stocks, but sometimes replacement is the best answer.
SCOPE ISSUES
• Lock Rings — This year alone I have seen nine lock rings on scopes that are not tight. Guess what that does to your group? Make sure yours are tight.
• Big Tubes Need Tension — We’ve observed that some 30mm scope rings are not getting tight enough, and scopes are slipping in the rings under recoil. This will cause point of aim movement.
• Windage Bases — If you’re using a conventional-style single dovetail with rear windage adjustment, make sure both sides of the windage screws are tight. This can induce both windage AND vertical issues since the rear ring is held down by the windage tension.
AWARENESS of CONDITIONS and READING WIND
• Basic Wind-Reading Rule–If you do not know how to read wind flags or are very inexperienced, try to shoot your group with the flags all going in one direction.
• Rate of Fire — The longer you wait between shots when a condition is changing, the more the condition change will affect your shots.
• Look Far and Wide — Learn to look at the whole field of flags, not just the row in front of you. Many times a change quite a ways out will cause shot to go out of your group well before that change shows up in front of your bench.
• Don’t Fear the Wind — When you realize that the wind is your friend you will become a much better benchrest shooter. By this I mean that wind skills can separate you from other shooters who have equally good equipment. To learn how to read the wind, you must practice in challenging winds, not only in good conditions.
• Watch Wind Direction AND Velocity — Pay attention to angle changes on flags. Even though you see the same windspeed indicators, angle changes make a big difference in your groups.
• Watch While You Wait — Between courses of fire, whenever possible, watch conditions on the range. That way you will be aware of any changes in conditions since your last group and you will be mentally prepared for the new condition.
SPECIAL ADVICE for HUNTING RIFLES
• Clean That Barrel — Most hunting rifle barrels do not get cleaned enough. If you keep barrel clean it will shoot better for you. You should clean your barrel well after every 10 to 12 shots. If you’re lazy, just use Wipe-Out.
• First Shot Inconsistency — Most hunting rifles will not put the first shot (after cleaning) with the subsequent shots. So, after cleaning, if you have a rifle that tosses that first shot high or wide, then shoot one fouling shot before going hunting or before you shoot for group.
• Barrel Heat — Thin-contour “sporter” barrels WILL change point of impact as they heat up. When testing loads for your hunting rifle, take your time and don’t let the barrel get hot on you.
How to Fill Shooting Sandbags Most Effectively
For both front and rear Edgewood bags, start by looking for the black nylon/cordura flap. This flap will have white stiches running along both sides. Note that the flap is actually two pieces of nylon/cordura which are sewn together. These two pieces must be separated at the end where there are no stitches in order to insert a funnel or other filling device.
Hold the bag so that the flap is pointed straight up and fill half way. Using a blunted rod and alternating between filling and packing, begin packing the sand firmly into the bag until the shape is uniform and you are satisfied with the firmness. Slam the base of the bag firmly on the bench several times to compact and evenly seat the sand. Then, check to see if more sand needs to be added. Repeat this process for the ears if you are filling a rear bag. Note that as the sand continues to condense during use, the bag may occasionally require additional sand until it reaches maximum capacity. NOTE: This tip is from Creedmoor Sports, which carries Edgewood Shooting Bags.
Edgewood offers an innovative rear Twisted Gater bag with an unusual asymmetrical footprint. This provides arm/hand support for the shooter while still providing superb rear support for your bench rifles.
SANDBAG Fill Options — Yes Weight Matters
For most shooting applications, “heavy is good” when it comes to sandbags. The more your sandbag weighs, the better it will resist movement or mis-alignment that can throw off a shot. In order to increase the weight of their rear bags, serious shooters have turned to exotic sand formulations that offer greater density (hence higher weight by volume) than plain silica sand (aka “play sand”).
In this article, Jason Baney reviews three popular alternatives to play sand for rear sandbags. He tested each variety to determine its density, i.e. how much volume it would displace per pound. Then he calculated how much each type of sand would weigh in various sizes of rear sandbags: standard, large, and ultra-large (Bigfoot). Check our Rapid Reference Chart to see how much weight you can add to your sandbag by switching to heavy sand.
Is heavy sand worth the added expense? For serious shooters, the answer is yes. More mass equals more stability, and a more stable bag will help you shoot tighter groups. By switching from conventional sand to Zircon or Chromite, you can DOUBLE the weight of sand in your rear bag.
Shown above are the SEB Bigfoot Bags. Note that the bags sit perfectly flat — there is no bulge on the bottom even though the bags are “packed to the brim with sand”.
Heavy Sand — Weighing the Benefits by Jason Baney
Many serious Benchrest shooters fill their sand bags with “heavy sand”. This practice may seem “overkill” to most shooters, but its benefits are realized quickly when shooting from a bench. Heavy sand is more dense than normal silica “play sand” and therefore makes the sandbag heavier and more stable. How much heavier is the heaviest sand? Check the chart below and you’ll see that Zircon sand weighs essentially TWICE as much as ordinary play sand. More weight equals more inertia opposing bag movement, plus more gravity-induced “stiction” on the bottom of the bag. In other words, using heavy sand helps your rear bag stay planted on the bench during a string of fire. When you shoot a hard-recoiling gun, the difference between a bag filled with play sand vs. Zircon is very noticeable. The Zircon-filled bag stays put. The play sand-filled bag may not.
Rapid Reference Chart
Comparative Sand Weights by Sandbag Size
SandBag Type
Play Sand
Riverbed Sand
Chromite
Zircon
Standard 5″x6″
5.1 lbs.
7.9 lbs.
9.9 lbs.
10.1 lbs.
Large 6″x8″
6.8 lbs.
10.5 lbs.
13.2 lbs.
13.4 lbs.
BigFoot 6″x13″
10.2 lbs.
15.8 lbs.
19.7 lbs.
20.1 lbs.
Weight Increase Compared to Play Sand
Zincon +98%
Chromite +94%
Riverbed Sand +55%
The Benefits of Heavier Sand
Heavy Sand helps your sandbag resist the tendency to shift or change alignment (relative to the stock) during recoil. This ability to maintain sandbag alignment is vital when shooting competitive Benchrest, either short-range or long-range. Having to fight a “migrating” rear bag during a group at 1000 yards will not do anything to help your accuracy. In non-competitive use, heavy sand can still benefit shooters. Friction from the stock on the rear bag, or bumping the bag on recoil with either a body part or pistol grip can move a lighter bag out of place and necessitate realigning the bag to get on target.
Of course there are some shooting situations where you don’t need (or don’t want) maximum sandbag weight. During a “walk-around” varmint session you may prefer a lighter bag. Beanbags that I carry around the groundhog fields stay filled with plastic beads, making the bag handier to tote. But, any rear bag used on a bench will be as heavy as I can make it while still using “sand” as filler.
Heavy Sand, Lead Shot, and Competition Rules
Some will say, “Well if you want a heavier sandbag, why not just add lead shot?” That is a great idea, but as far as I know, it is also illegal in every form of Benchrest competition. The material in sandbags must actually be “sand”, and only sand. It’s tempting to filter in a mix of shot and sand to increase weight, but that would also violate the rules.
Heavy Sand — Available Types and Properties
Heavy sand comes in several different varieties. In this article we tested three types: Zircon, Chromite, and commercial Riverbed sand (Exo-Terra brand “Reptile Sand”). All these are heavier alternatives to normal silica “play sand.” There are other types of Heavy Sand not tested here, such as Garnet Sand, which is between Chromite and Zircon in weight.
Sources: ProtektorModel.com sells black “Heavy Sand”, basically chromite. Large quantities of Zircon and Chromite are available from IFS Industries, and other industrial suppliers.
Exo-Terra Riverbed sand (amber). Available at pet stores.
Silica “Play Sand” (tan or light gray). Available at Home/Garden stores.
Zircon — Heavy-Weight Champion
To my knowledge, “Dupont Zircon M” is the heaviest “sand” that a normal human can acquire. It is also the most expensive. Zircon is a very light tan/brown color and is very similar in appearance to normal sandbox “play sand”. Zircon is normally rated as having the greatest density among heavy sands and it has the smallest particle size, though some Chromite sand density values overlap the Zircon numbers.
1.00 pound of Zircon displaces 149cc vs. 295cc for Play Sand. So, that means Zircon is 98% heavier than an equal volume of Play Sand.
CONSUMER TIP: Real ZIRCON sand is TAN in color, not black or dark gray. Some “heavy sand” vendors promise Zircon but deliver a dark gray sand that is something else entirely!
Chromite — Almost as Heavy as Zircon, and 30% Cheaper
Chromite sand is nearly the same density as Zircon but it costs quite a bit less. Chromite typically sells for about 25-30% less than Zircon (comparing bulk prices of both types of sand). Chromite sand is black in color. So when you buy “heavy sand,” make sure you are getting what you pay for.
1.00 pound of Chromite displaces 152cc vs. 295cc for Play Sand. So, that means Chromite is 94% heavier than an equal volume of Play Sand.
Riverbed Sand — Weighs Less but Costs More than Chromite
Riverbed sand, is about 30% less dense than Zircon or Chromite, but is about 150% more dense than silica sand. Depending upon where you buy this sand, and the quantity, you will most likely pay more for this sand than you would Zircon or Chromite. Riverbed sand is a conglomerate of several different sizes and colors and appears red and black. Unless you are unable to get Zircon or Chromite, I would not bother with the riverbed sand.
1.00 pound of Riverbed Sand displaces 190cc vs. 295cc for Play Sand. So, that means Riverbed Sand is 55% heavier than an equal volume of Play Sand.
Density/Volume Testing and Weight Comparisons
All four sand varieties mentioned above were tested for volumetric density by weight. Each type of sand was weighed out to 1.00 lbs. on a commercial postal scale. Each 1.00 lb sample of sand was then poured loosely into a 600ml beaker and shaken minimally to level the top surface. This served to determine the volume that the sand occupied.
1.00 pound of sand displaced the following volumes:
Zircon: 149 cc
Chromite: 152 cc
Riverbed sand: 190 cc
Play Sand: 295 cc
How do the density-volume numbers translate to the real world? Here is an estimate of how much each sand would weigh in various sizes of rear bag:
Standard Bunny Ear Bag
5″ by 6″ footprint or about 1500cc
Zircon: 10.1 lbs.
Chromite: 9.9 lbs.
Riverbed Sand: 7.9 lbs.
Play Sand: 5.1 lbs.
Protektor Doctor Bag
6″ by 8″ footprint or about 2000cc
Zircon: 13.4 lbs.
Chromite: 13.2 lbs.
Riverbed Sand: 10.5 lbs.
Play Sand: 6.8 lbs.
Seb BigFoot Rear Loaf Bag
6″ by 13″ footprint or about 3000cc
Zircon: 20.1 lbs.
Chromite: 19.7 lbs.
Riverbed Sand: 15.8 lbs.
Play Sand: 10.2 lbs.
Conclusions and Recommendations
What’s the best choice? For most users, we recommend Chromite. Chromite delivers nearly the same bag weight as Zircon but is more economical to buy. But for those who demand the maximum weight in their sandbag (without consideration of cost), Zircon is the top choice because it is sold at a finer grade (higher density) than Chromite. However, Chromite will save you money, and deliver very nearly the same amount of weight by volume. When purchased in bulk, Chromite is typically 25-30% LESS expensive than Zircon.
I would not suggest using the Riverbed sand unless you really need to fill a sandbag immediately and can’t wait to locate a source for either Zircon or Chromite. Keep in mind that Sinclair Int’l and other major mail-order vendors do sell heavy sand (though Zircon and Chromite may be much less expensive when purchased in larger quantities from local industrial sources.) The price of the Riverbed sand will vary quite a bit depending on the pet store and quantity bought. The Riverbed sand I tested, Exo-Terra Reptile sand (photo right), was fairly expensive as purchased at a pet store.
Bottom Line: When it comes time to fill your new rear bag, you may want to save a few dollars and go with cheaper Chromite sand, but if you want to gain every bit of weight possible, step up to the heavier Zircon.
Lenzi Rear bags work very well and are popular with top competitors. This are sold through PMA Tool.
A while back our Aussie friend Stuart Elliot of BRT Shooters Supply filmed some interesting videos at the QTS range in Brisbane, Australia. Stuart told us: “I was shooting in an Air Gun Benchrest match here in Brisbane, Australia. I finished my target early and was awaiting the cease fire and took a short, slow-motion video of windflag behavior.” You may be surprised by the velocity changes and angle swings that occur, even over a relatively short distance (just 25 meters from bench to target).
Here are windflags in slow motion:
The flags show in the videos are “Aussie Wind Flags”, developed by Stuart Elliot. These are still produced in Australia, and are now available through BRTFlags.com.
Here is a video in real time:
Stuart says this video may surprise some shooters who don’t use windflags: “Many people say the wind doesn’t matter. Well it sure does — whether for an airgun at 25 meters or a long range centerfire at 1,000.” This video illustrates how much the wind can change direction and velocity even in a small area.
.009” Group Record Stood for 40 Years
In 1973 Mac McMillan shot an amazing 100-yard, .009″ five-shot group in a benchrest match. The .009″ group was measured with a 60x microscope for verification. Mac McMillan shot the group using a handbuilt prototype McMillan rifle with an early McMillan stock.
Mac’s .009″ group was the “Holy Grail” of rifle accuracy. This .009″ record was considered by many to be unbreakable, a record that would “stand for all time”. Well, it took 40 years, but someone finally broke Mac’s record with an even smaller group. In 2013, Mike Stinnett shot a .0077″ five-shot group using a 30 Stewart, a .30 caliber wildcat based on the 6.5 Grendel. Stinnett’s NBRSA record .0077″ group now stands as the smallest 100-yard group ever shot in registered benchrest competition.*
Stinnett’s success doesn’t diminish the significance of Mac McMillan’s .009″ group in the history of benchrest competition. For four decades Mac’s group stood as the ultimate standard of rifle accuracy*. For those of you who have never seen Mac McMillan’s .009″ group, here it is, along with the NBRSA World Record certificate. The target now hangs in the McMillan Family Museum.
*Somebody else might claim a smaller group, but unless moving backers or electronic targets were used, it cannot be verified. Moving target backers are used at registered benchrest matches to ensure that five (5) shots are actually fired in each group. That eliminates any doubt.
This impressive 15-round group was shot by Jim See of Elite Accuracy.
Different Shooting Disciplines Demand Different Levels of Precision/Accuracy
In the rapid-fire 3-Gun game, you could probably “clean” most stages with a 2-MOA rifle. By contrast, in the short-range group benchrest game, to compete with the best, you’ll need a rifle that shoots in the “ones” (i.e. 0.1-0.19 MOA) in perfect conditions. In 1000-yard F-Class competition, the top shooters want a rifle that will hold one-third-MOA of vertical at that distance.
What is your standard of accuracy? How good is “good enough”. Jim See, a skilled gunsmith and successful PRS competitor, recently answered that question for his tactical discipline. For the kind of matches Jim shoots, he likes to have a rifle that will hold half-MOA for five (5) shots, 3/4-MOA for 15 shots, and 1 MOA for twenty shots. Remarkably, Jim’s rifle can do that with factory ammo. Above is an impressive 15-shot group shot with .260 Remington Federal Premium Ammo.
“I say it all the time, my loads need to print 5 under 1/2″, 10 under 3/4″, and 20 under 1″. It’s simple, if a hot barrel will keep 20 rounds fired in succession under my standard it will be a good barrel and load for Precision Match Shooting. Federal Premium Gold Metal Match .260 with Sierra bullets made the cut for me today. 15 consecutive shots under 3/4 MOA.” –Jim See
It’s said that you “can never have too much accuracy”, but there are acceptable standards for each discipline, and they’re not the same. A 100/200 yard Benchrest shooter will be sorely disappointed with a rifle/ammo set-up that can only deliver half-MOA. On the other hand, a PRS competitor like Jim See can achieve great success with a lesser degree of precision. This means you can save time and money. You can run your barrels longer between cleanings, and you don’t have to go “full OCD” when loading your ammo. The PRS shooter does not need to weigh-sort primers, or load powder to single-kernel standards. Proof is the performance. Jim See has been a podium finisher at many PRS and tactical events. Learn more about Jim’s gunsmithing and training operations at Jim’s Facebook Page.
Download This Load Development Target
Jim’s target seemed a bit familiar. AccurateShooter.com created this Diamond and Dot Target a few years back. On each aiming point, there are high-contrast black horizontal and vertical lines for aligning your cross-hairs. The gray circle lets you see the bullet impacts above, without obliterating the red diamond, which is quite useful for precise aiming (we put fine cross-hairs on the points of the diamond). This target sheet includes data entry tables below each of the three aim points. There are many other free targets out there, but this format is very popular. We’re pleased to see Jim using it. You can download this and dozens of other FREE Targets from the AccurateShooter.com Target Page.
Barrel-maker Dan Lilja’s website, RifleBarrels.com has an excellent FAQ page that contains a wealth of useful information. On the Lilja FAQ Page you’ll find answers to many commonly-asked questions. For example, Dan’s FAQ addresses the question of barrel life. Dan looks at factors that affect barrel longevity, and provides some predictions for barrel life, based on caliber, chambering, and intended use.
NOTE: This article was very well-received when it was first published. We are reprising it for the benefit of readers who missed it the first time.
Dan cautions that “Predicting barrel life is a complicated, highly variable subject — there is not a simple answer. Signs of accurate barrel life on the wane are increased copper fouling, lengthened throat depth, and decreased accuracy.” Dan also notes that barrels can wear prematurely from heat: “Any fast varmint-type cartridge can burn out a barrel in just a few hundred rounds if those rounds are shot one after another without letting the barrel cool between groups.”
Q. What Barrel Life, in number of rounds fired, can I expect from my new barrel?
A: That is a good question, asked often by our customers. But again there is not a simple answer. In my opinion there are two distinct types of barrel life. Accurate barrel life is probably the type most of us are referencing when we ask the question. But there is also absolute barrel life too. That is the point where a barrel will no longer stabilize a bullet and accuracy is wild. The benchrest shooter and to a lesser extent other target shooters are looking at accurate barrel life only when asking this question. To a benchrest shooter firing in matches where group size is the only measure of precision, accuracy is everything. But to a score shooter firing at a target, or bull, that is larger than the potential group size of the rifle, it is less important. And to the varmint hunter shooting prairie dog-size animals, the difference between a .25 MOA rifle or one that has dropped in accuracy to .5 MOA may not be noticeable in the field.
The big enemy to barrel life is heat. A barrel looses most of its accuracy due to erosion of the throat area of the barrel. Although wear on the crown from cleaning can cause problems too. The throat erosion is accelerated by heat. Any fast varmint-type cartridge can burn out a barrel in just a few hundred rounds if those rounds are shot one after another without letting the barrel cool between groups. A cartridge burning less powder will last longer or increasing the bore size for a given powder volume helps too. For example a .243 Winchester and a .308 Winchester both are based on the same case but the .308 will last longer because it has a larger bore.
And stainless steel barrels will last longer than chrome-moly barrels. This is due to the ability of stainless steel to resist heat erosion better than the chrome-moly steel.
Barrel Life Guidelines by Caliber and Cartridge Type
As a very rough rule of thumb I would say that with cartridges of .222 Remington size you could expect an accurate barrel life of 3000-4000 rounds. And varmint-type accuracy should be quite a bit longer than this.
For medium-size cartridges, such as the .308 Winchester, 7×57 and even the 25-06, 2000-3000 rounds of accurate life is reasonable.
Hot .224 caliber-type cartridges will not do as well, and 1000-2500 rounds is to be expected.
Bigger magnum hunting-type rounds will shoot from 1500-3000 accurate rounds. But the bigger 30-378 Weatherby types won’t do as well, being closer to the 1500-round figure.
These numbers are based on the use of stainless steel barrels. For chrome-moly barrels I would reduce these by roughly 20%.
The .17 and .50 calibers are rules unto themselves and I’m pressed to predict a figure.
The best life can be expected from the 22 long rifle (.22 LR) barrels with 5000-10,000 accurate rounds to be expected. We have in our shop one our drop-in Anschutz barrels that has 200,000 rounds through it and the shooter, a competitive small-bore shooter reported that it had just quit shooting.
Remember that predicting barrel life is a complicated, highly variable subject. You are the best judge of this with your particular barrel. Signs of accurate barrel life on the wane are increased copper fouling, lengthened throat depth, and decreased accuracy.
Benchrest Barrel Life — You May Be Surprised
I thought it might be interesting to point out a few exceptional Aggregates that I’ve fired with 6PPC benchrest rifles with barrels that had thousands of rounds through them. I know benchrest shooters that would never fire barrels with over 1500 shots fired in them in registered benchrest matches.
I fired my smallest 100-yard 5-shot Aggregate ever in 1992 at a registered benchrest match in Lewiston, Idaho. It was a .1558″ aggregate fired in the Heavy Varmint class. And that barrel had about 2100 rounds through it at the time.
Another good aggregate was fired at the 1997 NBRSA Nationals in Phoenix, Arizona during the 200-yard Light Varmint event. I placed second at this yardage with a 6PPC barrel that had over 2700 rounds through it at the time. I retired this barrel after that match because it had started to copper-foul quite a bit. But accuracy was still good.
Credit our buddy Joe Friedrich for this simple yet effective accessory for your benchrest rifle. Joe shoots a .22 LR benchrest rig with a barrel tuner. When he added weights to his tuner, he found his rifle no longer balanced well. He wanted to add some weight in the rear without drilling holes in the stock. He also wanted the weight to be removable, and easily placed on another rifle in his stable. He wanted a weight that could be moved from gun to gun as needed.
At a local sporting goods shop Joe found a 1.5-lb ankle weight that comes in a padded, tubular elastic cover. It’s like a 1.5-lb sausage in a soft, stretchy nylon cover. (Imagine a really fat, heavy bungee cord). Joe simply attached a plastic zip tie at the end to make a loop that fits perfectly over his buttstock. CLICK HERE for full-screen photo.
To “tune” the rifle’s balance, Joe just slides the ankle weight fore and aft on the stock. We have tried this moveable ankle weight on a variety of different BR stocks (including a McMillan Edge) and it worked perfectly. This is a great invention, and would work with sporter rifles and ARs just as well.
NOTE: Obviously, this ring will increase the measured weight of your rifle. So, if you are competing in a registered match with weight restrictions, you have to ensure that your rifle still makes class weight limits with the ankle weight ring in place.
Editor’s NOTE: Shelley Davidson passed away in 2008 after a courageous battle with cancer. He was one of the great innovators in benchrest rifle design. This article, written before Shelley died, showcases Shelley’s creative talents at their best. His “Tinker Toy” design will always be a tribute to Shelley’s fabricating skills and imagination.
Shelley Davidson — a brilliant innovator. R.I.P. Shelley — you will not be forgotten.
Shelley Davidson’s peers called his radical rifle the “Tinker Toy” gun. We call it revolutionary. Even now, 14 years after its creation, there’s nothing quite like it. This innovative, skeleton design threw conventional wisdom to the winds. Shelley readily concedes he “broke the rules” of benchrest rifle building. But this was inspired rule-breaking, because Davidson’s rifle shot like a house on fire. The Tinker Toy gun won its first matches, both for Score AND for Group. And this rifle also delivered many “zero groups” in Gene Begg’s Texas Tunnel. Hats off to Shelley for conceiving and building a truly radical rifle that was also wicked accurate and successful in competition.
Tinker Toy 30 BR — Radical As It Gets
Report by Shelley Davidson
Although I’m not big on naming rifles, my shooting buddies have christened the gun “Tinker Toy.” I can live with that as it does kind of look as if it was made with a Tinker Toy set.
Origins of the Project
This project began with some wild ideas I had in the fall of 2006 about using magnets to tune a barrel. My idea was to use one magnet on the barrel and another on the stock so they pushed against each other to counter gravity-induced barrel sag (and possibly) tame barrel vibration in a beneficial manner. The only way to test these ideas was to build the device and mount it on a gun. That meant I had to build a new rifle because there was no place to mount a magnet on the stock of a conventional benchrest rig. I had a Kelbly-stocked heavy varmint stock with a Michael Kavanaugh paint job on it. I didn’t think Kav would ever forgive me if I started drilling holes in one of his works of art. My light varmint was in a carbon fiber Scoville stock that costs about a grand. Drilling into the Scoville for an experiment just smacked of bad judgment. So, the magnet thing was my first motivation for designing a new stock. As long as I was building from scratch I decided to offset the barrel and action 0.75″ to the right to counteract the spin/torque from the bullet.
Although there’s nothing new here, my second motivation was to build a 30BR that could shoot in the 10.5 lb light varmint class in NBRSA. The magnetic tuner will automatically make this gun illegal in the IBS. The IBS has declared all barrel attachments un-safe and have outlawed them. I personally feel that the IBS really outlawed all barrel attachments to prevent experimentation and innovation. But at least we have NBRSA matches.
Designing the New Gun — Thinking “Outside the Box”
Once I’d decided to build a lightweight stock that could support experimental devices out near the muzzle, I started drawing up some rough plans. I also took a trip to Jerry Stiller’s shop in Wylie, Texas for a brainstorming session with Jerry, the maker of Viper and other Benchrest actions. Jerry is a school-trained mechanical engineer and thinks differently than I do. I came away from Stiller’s shop with my design roughed out and sketched on paper. The design violated several covenants of conventional wisdom for building competition BR rifles. For instance, two-piece stocks stress the action. Stress reduction is why most BR rifles are glued into the stock. Another myth is that metal stocks vibrate too much so wood or foam-filled fiberglass or carbon fiber are used.
Tinker Toy Rifle DESIGN FEATURES
Shelly Davidson’s Rifle was so innovative, that almost every feature, except the bare action, is very different than you’ll find on most Benchrest rigs. Accordingly we felt it would be useful to isolate and describe the key design features, from stem to stern. Click thumbnails to view FULL-SIZE PHOTOS.
Front Bracket with Magnetic Tuner
The tuner consists of one rare earth magnet attached to the stock and another attached to a barrel sleeve with the magnets oriented so as to make the magnetic force repel each other. The purpose is to counter “barrel droop” and, hopefully, dampen barrel vibration. The lower magnet is carried on a threaded shaft (with lock ring), allowing the magnet to be raised up and down to adjust the “up push” on the barrel.
Tubular Fore-Arm Supported by Brackets
Three brackets support two tubes, one on either side of the barrel. The rear-most bracket is sandwiched between the barrel and the action. Four inches forward (max distance allowed for barrel blocks) a second bracket grips the barrel. Near the muzzle a third bracket secures the ends of the tubes and holds the magnetic tuner. To allow barrel offset, the left tube is 1″ diameter tube while the right tube is 5/8″ diameter.
Offset Barrel The rifle rests on a 3″ wide plate attached to the underside of the two fore-end tubes. With the plate centered in the front sandbag, the barreled action is actually offset 0.75″ to the right (looking forward from the breech). The purpose of this offset is to keep more weight on the right side to counter the tendency of the rifle to torque counter-clockwise. Two different diameter tubes allow for the built-in offset.
Floating Action without Sub-Support or Bedding
On the Tinker Toy gun, the action serves as a load-bearing assembly, holding the barrel in the front, and the skeleton buttstock (or “keel”) in the rear. Shelley was told that accuracy would suffer if you stressed a benchrest action in this manner but that proved untrue. It is a very simple solution to building a rifle, and it eliminates the need to bed the action. The forearm attaches to the action via a bracket installed like a recoil lug.
Skeleton Rear “Keel” Affixed Directly to Action
Davidson’s Tinker Toy does not have a conventional rear buttstock. Instead there is low-profile, v-shaped metal “keel”, as Davidson calls it, that rides the rear bag. The keel is supported by a tubular backbone that attaches at the rear of the Diamondback action. At the butt end is an aluminum plate covered with bubble wrap that serves as a butt pad. The skeletonized rear section helps the rifle maintain a very low center of gravity.
Locked Scope with External Windage and Elevation Adjustment
Shelley ran an older Leupold 36X Benchrest Scope with front-adjusting objective. To eliminate slop or loose tolerances in the erector mechanism that could cause changes in point of impact, the internals have been locked up by Jackie Schmidt. To move the cross-hairs relative to the bore axis, Shelley has a special Jewell/Foster rear ring that allows a limited amount of lateral and vertical movement of the entire scope body.
TINKER TOY SPECIFICATIONS
Action: Stiller SS Diamondback Drop-Port (1/2″ short), with .308 Bolt Face.
Barrel: Shilen .308 caliber, 17-twist, HV.
Chambering: 30BR, .330″ neck, Pacific Tool & Gauge Robinett Reamer.
Stock: Davidson Custom Tubular Stock with 0.75″ Offset Barreled Action.
Tube Construction: 6061 Aluminum, 1″ diameter (left), 5/8″ diameter (right).
Load: H4198 powder and 118gr Ronnie Cheek bullets. Loaded to 2980 fps.
Trigger: Jewell, 2 ounce BR.
Tuner: Custom, Adjustable with Opposing Magnets.
Optics: Leupold 36X (locked by J. Schmidt).
Rings: Jewell Foster External Adjusting Rings.
Stiller Diamondback Action and Shilen 17-Twist Barrel
I had wanted to use an aluminum Stiller Cobra drop port with a 6mmBR bolt face but Jerry had none in stock and he estimated it would be a year before one was available. Although I’ve waited for up to a year for an action in the past, I wanted to build this rifle during the fall of 2006 while the weather was pleasant enough to work in my unheated and un-air-conditioned garage shop. Jerry did have a 1/2″ short stainless steel Diamondback in stock so I purchased it even though it would add 3 ounces to the gun compared to the aluminum Cobra. Three ounces is a lot of weight when you’re working with a 10.5-lb limit. I had a heavy varmint contour Shilen 17-twist barrel that would work nicely and I had a Jewell trigger on a rifle that I wasn’t using at the time. I also decided to use my Leupold 36X (locked-up by Jackie Schmidt) with the Jewell/Foster adjustable rings.
Building the Tube Fore-Arm and Brackets
I took a wild guess as to tubing thickness and settled on .035″ for the 1″ left fore-arm tube and .058″ for the 5/8″ right fore-arm tube. All of the flat stock and tubes are 6061 Aluminum. I did the lathe work and the mill work and every evening I’d put the parts together and think about the proper way to proceed.
When the parts were mostly made, I started thinking that this was a truly ugly rifle. I thought about painting it but that wasn’t a good option as many of the parts are designed to slide over others and glue together. Anodizing was the best answer so while looking on the Internet for local anodizing shops I Googled “Home Anodizing”. Sure enough there were a few sites that told about how to anodize at home. I picked up some battery acid from NAPA Auto Supply, some Rit Clothes Dye from Wal-Mart, and a bunch of distilled water from the grocery store. Using an old battery charger as my dc power supply I started anodizing and dying the eighteen parts that went into the stock. Although I had to strip and re-anodize some of the parts, the work turned out acceptable.
Putting it All Together–Lug-Mounting the Fore-Arm and Lots of Epoxy
The barrel contour had to be modified to work with the stock which attaches by way of a rear plate which mounts like a recoil lug and a plate that ties the barrel and the stock tubes together 4″ forward of the bolt face. The four-inch maximum distance is a NBRSA rule concerning barrel blocks.
The recoil lug-style stock mount is probably the only truly innovative thing I did other than the opposing-magnet tuner. Basically, the rear bracket is sandwiched between the receiver face and the barrel shoulder–positioned where a conventional recoil lug would go. I also added a brass ring (visible in photo) between the anodized bracket and the barrel. This was done to distribute loads over a wider surface area. (I was concerned that the bracket material was fairly soft and I didn’t want to crush it as I torqued the barrel in place.) After fitting the barrel and plates I glued the entire gun together using epoxy and various LocTite adhesives. The rest of the parts were assembled but I did not Loctite the scope bases since I thought I’d be disassembling the rifle for re-work after the first trials. That came back to bite me during later testing when the gun started shooting erratically and I went down a couple of blind alleys before finding the loose bases.
Range Testing–Results Are Very Positive
The first range session was a real shocker. Even though the wind was up to 10mph and twitchy, the rifle showed promise from the very first shot. I really didn’t expect that kind of performance without, at least, some rework. After sighting in, I shot five, 5-shot groups that, when averaged together, measured .223″. That’s good enough to win some benchrest group matches. But I wasn’t finished with the gun yet–I still wanted to try out my magnetic tuner concept.
The Magnetic Tuner
Next, I built the magnetic tuner. The tuner consists of one rare earth magnet attached to the stock and another attached to a barrel sleeve with the magnets oriented so the magnetic forces repel each other. In order to test the magnets and to determine if the rifle really shot as well as it seemed to, I took it to Gene Beggs’s shooting tunnel in Odessa, Texas. I spent two days at the tunnel testing loads and then installed the magnetic tuner. The gun shoots well with the magnets and shoots well without them. I suppose I can’t make any claims as to how much, if any, improvement the magnets make. Gene said that my gun was the most accurate rifle to be tested at his one-year-old shooting facility: “Shelley Davidson brought one of the most unusual rifles I had ever seen; he called it his ‘Tube Gun.’ And boy, did it ever shoot! It still holds the record in the tunnel as the rifle that shot more zeros than any other to date.” I definitely recommend Gene’s facility for testing and refining shooting techniques and loads.
Competition — Tinker Toy Won Both Score and Group Matches
Finally the big day arrived when I’d shoot the first match with my new gun. The North Texas Shooters Association was holding its first club match of the 2007 season. At the Denton, Texas matches we shoot a Score Match in the morning and a Group Match in the afternoon. The March event was at 100 yards and the April match will be at 200 yards and so on alternating throughout the benchrest season.
Match One–Tinker Toy Wins Score with a 250 – 17X
Since the gun is chambered in 30BR and that chambering is almost immune to tuning woes, I preloaded 130 rounds with H4198 powder and 118gr Cheek bullets. I used my SEB front rest and rear bag which are made by Sebastian Lambang in Indonesia. Everything came together, and Tinker Toy demonstrated that the accuracy it showed in the tunnel was no fluke. The gun shot great and I won the morning match with a 250, 17X. The day was quite windy and the next best shooter scored a 250, 15X. So I’d chalked up my first win.
Match Two–Tinker Toy Wins Group with a .2282″ Agg Tinker Toy won the afternoon group match I entered with a five-group Aggregate of .2282″. (The second place score was .2568″.) My groups were .149″, .197″, .243″, .302″ (oops), and .250″. You know how some folks say a 30BR can’t be competitive with a PPC? Well that .2282″ Agg won’t break any records, but it is good enough to win some regional registered BR matches. So this rifle has demonstrated an ability to win in both Score and Group matches. Obviously I have a very good Shilen barrel, great Cheek bullets and the rest of the components are doing their jobs as well. But, the stock is also working well.
Score Shooting vs. Group Shooting–The Rules
In a score match, the shooter shoots one bullet at each of five record targets, which are clustered on one target sheet. The Aggregate score of five of these targets determines the winner. If the shooter touches the 10 ring on all of his 25 targets he can score a “clean” 250 score. Usually there will be more than one shooter who scores a 250 so the winner is determined by the X-count. The 1/2″ 10-point ring has a 1/16″ dot in its center. Touching the X dot adds to the shooters X count. In short-range group matches, the shooter must try to put five bullets through the same hole. At each distance (100 or 200), five, 5-shot matches are scored, the group sizes are added together (MOA equivalent at 200) and the total is divided by five to arrive at an Aggregate score.
This site is for and about accurate shooters. So today we feature the short-range group Benchrest game, where it’s all about shooting tiny groups in the ones and even “zeros”. 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.
You don’t hear much about PacNor barrels in long-range competition, but FORUM member Wes J (aka P1ZombieKiller), proved that they can shoot “lights-out” in a rig assembled by a talented gunsmith. A few seasons back, Wes decided to upgrade a 6mmBR for mid-range benchrest and varmint matches. Wes tells us: “Since I restocked my 6BR … I have not had a chance to shoot it much since I have been playing the 100-200 game. I decided to take it out and do some playing at 500 yards. I have to give some serious props to my buddy (and fellow FORUM member) ‘PREACHER’ who did the chambering and barrel work for me. He can certainly make a gun shoot good. The barrel is a PacNor 1:8″ twist. My load was 105gr Berger VLDs pushed by 29.6 grains of Varget.” The five-round, 500-yard group shot by Wes J with his 6BR, measured just 1.240″, as measured by OnTarget software. Now that’s one accurate rig!
Five by Five — 5-Shot Group at 500 Yards, 1.240″, 0.237 MOA
This Editor knows something about the potential of a PacNor barrel. I have a 3-groove stainless PacNor SuperMatch on a Savage-actioned 6BR. This barrel shoots honest quarter-MOA in calm conditions, and it cleans up super-easy. The interior finish is so good, I’ve never had to brush the bore or use abrasives, and after 750 rounds it shoots as well as ever. I attribute the easy cleaning to the fact the lands in a PacNor 3-groove are wide and flat, so they are gentle on bullet jackets. I think accuracy is helped by the fact that my PacNor runs on the tight side (0.236 land dimension) with a good amount of choke. That works well with the 105gr Lapua Scenars and 103gr Spencers I like to shoot. You can read more about my rifle, nick-named the “Poor Man’s Hammer”, in this Feature Article from our archives. On one particularly calm day, in the hands of my friend (and ace trigger-puller) Joe Friedrich, the Poor Mans’ Hammer put 3 shots in under 0.200″ (measured center to center) at TWO Hundred yards. If you get a good one, PacNor three-grooves can definitely shoot.
Target Measurement with OnTarget Software
We used OnTarget software to measure the 5-shot group in the target above. This easy-to-use software is very repeatable, once you get a feel for plotting the shots. The latest On Target v2.25 Precision Calculator is FREE for a 15-day evaluation period. If you like it (and you will, trust us) there’s a modest $11.99 registration fee to activate the program. In addition to group size (in inches), OnTarget plots distance to aiming point, and the software automatically calculates the group’s vertical height, horizontal dispersion, average to center (ATC), and group size in MOA.
You can run a measurement on a scanned target or a photo of a target. You’ll need some known reference to set the scale correctly. The target above had a one-inch grid so it was easy to set the scale. Once you’ve set the scale and selected bullet diameter and target distance, you simply position the small circles over each bullet hole and the OnTarget software calculates everything automatically, displaying the data in a data box superimposed over the target image. To learn more about OnTarget Software, read AccurateShooter.com’s OnTarget Product Review. This article covers all the basics as well as some advanced “power user” tips. NOTE: Since the review was written, On Target has updated the software, and the free version now has a time limit.
In this article, Hall of Fame benchrest Shooter Speedy Gonzalez explains how to eliminate mechanical and gun-handling problems that cause vertical spread in your groups. Speedy’s article addresses the many human and the hardware factors that can cause vertical. 
• Front Bag Tension–Vertical can happen if the front sand bag grips the fore-arm too tightly. If, when you pull the rifle back by hand, the fore-arm feels like it is stuck in the bag, then the front bag’s grip is too tight. Your rifle should move in evenly and smoothly in the sand bags, not jerk or chatter when you pull the gun back by hand.
How to Fill Shooting Sandbags Most Effectively
For most shooting applications, “heavy is good” when it comes to sandbags. The more your sandbag weighs, the better it will resist movement or mis-alignment that can throw off a shot. In order to increase the weight of their rear bags, serious shooters have turned to exotic sand formulations that offer greater density (hence higher weight by volume) than plain silica sand (aka “play sand”).
Many serious Benchrest shooters fill their sand bags with “heavy sand”. This practice may seem “overkill” to most shooters, but its benefits are realized quickly when shooting from a bench. Heavy sand is more dense than normal silica “play sand” and therefore makes the sandbag heavier and more stable. How much heavier is the heaviest sand? Check the chart below and you’ll see that Zircon sand weighs essentially TWICE as much as ordinary play sand. More weight equals more inertia opposing bag movement, plus more gravity-induced “stiction” on the bottom of the bag. In other words, using heavy sand helps your rear bag stay planted on the bench during a string of fire. When you shoot a hard-recoiling gun, the difference between a bag filled with play sand vs. Zircon is very noticeable. The Zircon-filled bag stays put. The play sand-filled bag may not.
Dupont Zircon M (pale tan): 165-175 lb/cu.ft; avg. particle size 0.01″.
Prince Minerals Chrome CAST 7850 (Chromite) (black): 172 lb/cu.ft; avg. particle size 0.02″.
Zircon — Heavy-Weight Champion
Chromite — Almost as Heavy as Zircon, and 30% Cheaper
Riverbed Sand — Weighs Less but Costs More than Chromite
I would not suggest using the Riverbed sand unless you really need to fill a sandbag immediately and can’t wait to locate a source for either Zircon or Chromite. Keep in mind that 
.009” Group Record Stood for 40 Years
Credit our buddy Joe Friedrich for this simple yet effective accessory for your benchrest rifle. Joe shoots a .22 LR benchrest rig with a barrel tuner. When he added weights to his tuner, he found his rifle no longer balanced well. He wanted to add some weight in the rear without drilling holes in the stock. He also wanted the weight to be removable, and easily placed on another rifle in his stable. He wanted a weight that could be moved from gun to gun as needed.
The recoil lug-style stock mount is probably the only truly innovative thing I did other than the opposing-magnet tuner. Basically, the rear bracket is sandwiched between the receiver face and the barrel shoulder–positioned where a conventional recoil lug would go. I also added a brass ring (visible in photo) between the anodized bracket and the barrel. This was done to distribute loads over a wider surface area. (I was concerned that the bracket material was fairly soft and I didn’t want to crush it as I torqued the barrel in place.) After fitting the barrel and plates I glued the entire gun together using epoxy and various LocTite adhesives. The rest of the parts were assembled but I did not Loctite the scope bases since I thought I’d be disassembling the rifle for re-work after the first trials. That came back to bite me during later testing when the gun started shooting erratically and I went down a couple of blind alleys before finding the loose bases.
Match One–Tinker Toy Wins Score with a 250 – 17X
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.
Target Measurement with OnTarget Software
