This discussion of rear bag designs and fill levels may offer some new insights for many readers. By “tuning” your rear bag you can reduce hop on shot-firing and help your rifle track better. All that can translate to better scores, particularly with large-caliber rifles.
Tuning Your Rear Sand Bags
Over the years, noted gunsmith and a Benchrest Hall-of-Fame inductee Thomas ‘Speedy’ Gonzalez has learned a few things about “tuning” rear sandbags for best performance. On his Facebook page, Speedy recently discussed how sand bag fill levels (hard vs. soft) can affect accuracy. Speedy says you don’t want to have both your front and rear sandbags filled up ultra-hard. One or the other bag needs to have some “give” to provide a shock-absorbing function (and prevent stock jump). And you want to tune your fill arrangements to match your shooting style. Free recoil shooters may need a different fill levels than bag squeezers (who a softer bag but harder ears).
SAND BAGS & HOW TO FILL THEMby Speedy Gonzalez
I was asked several times by competitors at the S.O.A. Matches and F-Class Nationals as to how I fill my sand bags for benchrest competition. Here is a copy of a reply I gave several years ago:
Back in the old days, Pat McMillan told me: “You can not have two bags filled so hard that you gun bounces on them in the process of firing round at your target, especially if you have a rig with a very flexible stock. The bags must be set up in a manner for them to absorb the initial shock of the firing pin moving forward and igniting the primer.
Then [they must] maintain their shape and absorb the second shock wave as well the rearward thrust and torque of the rifle. What happens to the rifle when this is not done? Well let me tell you. The rifles have a very bad tendency to jump and roll in the bags. This causes many of those wild, lost shots that one can’t explain.”
Here’s some Good General Advice for Bag Set-up:
1. You should not have TWO hard bags [i.e. both front AND rear] in your set-up.
2. Heavy sand magnifies these phenomena.
3. If you are a bag squeezer, pack ears hard and leave bag pliable enough to squeeze for the movement required. You may pack front bag as hard as rules permit.
4. Free recoil shooters pack both bags firm, but not so hard as to allow stock jump. Especially if you have a stock with a very flexible forearm.
5. We use play-ground sand, also know as silica sand. I sift mine to get any large impurities out then mix it with 25% to 50% with Harts parakeet gravel to the desired hardness that I am looking for. The bird gravel keeps the sand from packing itself into that solid as a brick state.
Speaking of bricks — another thing that happens when shooters employ that heavy zircon sand is the ears form a low spot under them from recoil and then tend to rock back and forth with the rifle causing many low shots to crop up. Edgewood makes an Edgewood/Speedy rear bag specially reinforced under the ears to eliminate this scenario.
Show below are the latest 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”.
General Thoughts about Bag Construction and Ear Materials
I do not like the solid double-stitched leather bottoms. While this seems like a good idea, I see more shooters have problems because of them. They tend to slide around the bench and or slide with the rifle on recoil. The standard Protektor with Cordura rabbit ears and an Otto ring bag with a Cordura front would be what I would suggest to the new shooter or one of the Edgewood / Speedy rear bags, these mimic the “Donut” and feature a ring of leather around the bottom circumference that keep the bottom from rocking on the bench or ground[.]
One last note –If you use the Cordura bags, keep them sprayed with a good silicon spray or “Rain-Ex”. This keeps them from getting sticky. — Speedy
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Are you tired of struggling to fill your rear sandbags and other sand-filled shooting supports? With a conventional plastic funnel it can be difficult to get the bags filled to full capacity. It’s also time-consuming and awkward to keep pouring sand into a small funnel top.
21st Century Shooting has a solution — a tool that makes it WAY easier to fill all types of sandbags and sand-filled shooting rests, including PRS bags, Bulls Bags, and X-Bags. The 21st Century Sand Bag Filler has a large transparent bottle that holds a lot of sand. This attaches to a nicely-machined threaded grip section that feeds the sand into a small-diameter insert tube. This smaller tube easily fits in the small fill-ports of sandbags. The small tube also allows you to steer the sand flow to the corners of your bags to get a more even, uniform fill.
This video from F-Class John shows how to use the 21st Century Sand Bag Filler. John explains how to fill the sand bottle, than shows how to efficiently fill an Edgewood Dead-bottom bag with sand. John was impressed. At the 2:26 mark John notes: “This is pretty ‘kick ass’ … It is just sucking up the sand into this bag… that is fast”. John is sold on this tool: “I’ve got some giant SEB and Protektor bags. Before I had this tool, I’ve used any number of methods in the past and it’s probably taken me a good hour to pack a bag properly.” Now John says he can fill a big bag in a fraction of the time.
Along with benchrest rear bags, such as the new SEB Premium Bigfoot shown above, there are many other sand-filled support bags. Shown below are some popular bags. The Uncle Bud Bulls Bag has long been a favorite of varmint shooters. It’s very stable but does require a LOT of sand. The 21st Century tool will dramatically shorten filling time for a big Bulls Bag or X-Bag.
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During shooting season, there are probably 400 or more club “fun matches” conducted around the country. One of the good things about these club shoots is that you don’t have to spend a fortune on equipment to have fun. But we’ve seen that many club shooters handicap themselves with a few common equipment oversights or lack of attention to detail while reloading. Here are SIX TIPS that can help you avoid these common mistakes, and build more accurate ammo for your club matches.
1. Align Front Rest and Rear Bags. We see many shooters whose rear bag is angled left or right relative to the bore axis. This can happen when you rush your set-up. But even if you set the gun up carefully, the rear bag can twist due to recoil or the way your arm contacts the bag. After every shot, make sure your rear bag is aligned properly (this is especially important for bag squeezers who may actually pull the bag out of alignment as they squeeze).
Forum member ArtB adds: “To align my front rest and rear bag with the target, I use an old golf club shaft. I run it from my front rest stop through a line that crosses over my speed screw and into the slot between the two ears. I stand behind that set-up and make sure I see a straight line pointing at the target. I also tape a spot on the golf shaft that indicates how far the back end of the rear bag should be placed from the front rest stop. If you don’t have a golf shaft, use a wood dowel.
2. Avoid Contact Interference. We see three common kinds of contact or mechanical interference that can really hurt accuracy. First, if your stock has front and/or rear sling swivels make sure these do NOT contact the front or rear bags at any point of the gun’s travel. When a sling swivel digs into the front bag that can cause a shot to pop high or low. To avoid this, reposition the rifle so the swivels don’t contact the bags or simply remove the swivels before your match. Second, watch out for the rear of the stock grip area. Make sure this is not resting on the bag as you fire and that it can’t come back to contact the bag during recoil. That lip or edge at the bottom of the grip can cause problems when it contacts the rear bag. Third, watch out for the stud or arm on the front rest that limits forward stock travel. With some rests this is high enough that it can actually contact the barrel. We encountered one shooter recently who was complaining about “vertical flyers” during his match. It turns out his barrel was actually hitting the front stop! With most front rests you can either lower the stop or twist the arm to the left or right so it won’t contact the barrel.
3. Weigh Your Charges — Every One. This may sound obvious, but many folks still rely on a powder measure. Yes we know that most short-range BR shooters throw their charges without weighing, but if you’re going to pre-load for a club match there is no reason NOT to weigh your charges. You may be surprised at how inconsistent your powder measure actually is. One of our testers was recently throwing H4198 charges from a Harrell’s measure for his 30BR. Each charge was then weighed twice with a Denver Instrument lab scale. Our tester found that thrown charges varied by up to 0.7 grains! And that’s with a premium measure.
4. Measure Your Loaded Ammo — After Bullet Seating. Even if you’ve checked your brass and bullets prior to assembling your ammo, we recommend that you weigh your loaded rounds and measure them from base of case to bullet ogive using a comparator. If you find a round that is “way off” in weight or more than .005″ off your intended base to ogive length, set it aside and use that round for a fouler. (Note: if the weight is off by more than 6 or 7 grains you may want to disassemble the round and check your powder charge.) With premium, pre-sorted bullets, we’ve found that we can keep 95% of loaded rounds within a range of .002″, measuring from base (of case) to ogive. Now, with some lots of bullets, you just can’t keep things within .002″, but you should still measure each loaded match round to ensure you don’t have some cases that are way too short or way too long.
5. Check Your Fasteners. Before a match you need to double-check your scope rings or iron sight mounts to ensure everything is tight. Likewise, you should check the tension on the screws/bolts that hold the action in place. Even on a low-recoiling rimfire rifle, action screws or scope rings can come loose during normal firing.
6. Make a Checklist and Pack the Night Before. Ever drive 50 miles to a match then discover you have the wrong ammo or that you forgot your bolt? Well, mistakes like that happen to the best of us. You can avoid these oversights (and reduce stress at matches) by making a checklist of all the stuff you need. Organize your firearms, range kit, ammo box, and shooting accessories the night before the match. And, like a good Boy Scout, “be prepared”. Bring a jacket and hat if it might be cold. If you have windflags, bring them (even if you’re not sure the rules allow them). Bring spare batteries, and it’s wise to bring a spare rifle and ammo for it. If you have just one gun, a simple mechanical breakdown (such as a broken firing pin) can ruin your whole weekend.
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Look carefully at the photo above. That stylish black rear bag doesn’t look anything like an Edgewood or Protektor — it’s a Lenzi bag from Italy. The front Bag-holder on the SEB Neo Rest is also a Lenzi product.
Lenzi Rear Sand Bag
Pat Reagin of PMA Tool offers a really superb rear bag that comes from Italy. Pat tells us: “We are now carrying rear bags made by Italian benchrester Alberto Lenzi. Made in Italy, these Lenzi bags are AWESOME! They are available for short range and one that is slightly taller for long range.” The Lenzi rear bags feature a big, 8″x6″ footprint with a thick, slightly concave base that sits very flat on the bench top. Lenzi bags are very stable with a reassuring “dead” feel on the bench. Guys who have tried this bag really like it. Pat says: “I can’t explain it, but the bag seems to absorb energy/recoil better than other bags — the gun tracks a little better and I get back on target really well.” CLICK HERE for more information: Lenzi Long Range Rear Bag | Lenzi Standard Rear Bag.
– Black leather with Cordura at stock contact points with blue stitching.
– 1/2″ flat between medium ears.
– Heavy 8″x6″ base with built-in “donut”.
– Weight about 15.5 lbs filled with heavy sand in bottom & white sand in ears.
– Bags offered with Nylon Ear Covering OR 3M Slick Ear Fabric.
Lenzi Replacement Top for SEB NEO Front Rest
A common complaint about the SEB NEO rest is the rest top, specifically the three-piece bag. This rest top made by Alberto Lenzi addresses the issue by replacing the entire rest top. The rest top features a more conventional design and includes a traditional style front bag that conforms to IBS and NBRSA rules.
We know that quite a few hunters and tactical shooters read the Daily Bulletin. Here’s a product for you guys that need a multi-purpose padded support that can be easily carried and adapted to a variety of positions (such as on platforms, vehicle hoods, as well as flat ground). This versatile bag can be used on the front (supporting the fore-end), or in the rear (supporting the buttstock). Made in the USA, “The Brick” Grippy Bag costs $39.95 from Armageddon Gear. Measuring 6″ x 3″ x 3″, “The Brick” is offered in two colors: Coyote Tan and Black.
Made by Armageddon Gear, and sold through the Armageddon Gear Store, “The Brick” has unique features that make it ultra-handy in the field. First the “grippy” outer material is rubberized and textured so it can provide a firm grip on a support surface as needed. Overlapping Velcro-lined straps allow the bag to be attached to a rifle fore-end, buttstock, tripod head, shooting sticks, or pack. The square cross-section provides secure contact between the rifle stock and support surface. You can easily adjust the firmness of the bag by adding or subtracting filler material. (Some guys will fill their Brick with sand; others may prefer beads or other lighter media to save weight.) The panel under the strap is nylon to allow the shooter’s hand to easily slide underneath the strap when desired.
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At the request of Forum members, we are reproducing this helpful article by gunsmith and Hall-of-Fame benchrest shooter Thomas “Speedy” Gonzalez
How to Reduce Vertical in Your Shot Groups
One of our Shooter’s Forum members recently built a new benchrest rifle. He was concerned because his groups were stringing vertically. This 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.
Hall of Fame benchrest Shooter Speedy Gonzalez has written a helpful article that explains how to eliminate mechanical and gun-handling problems that cause vertical spread in your groups. Speedy’s article addresses both the human and the hardware factors that cause vertical. CLICK HERE to read the full article. Here are a few of Speedy’s tips:
• Front Bag Tension — Vertical can happen if the front sand bag grips the fore-arm too tightly. If…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.
• Stock Recoil — Free-recoil-style 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. If you shoulder your gun, you need to 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.
• 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.
• Stock Flex — Some stocks are very flexible. This can cause vertical. There are ways to stiffen stocks, but sometimes replacement is the best answer.
• 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.
• 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.
• 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.
• Head Position — Learn to keep your head down and follow-through after each shot. Stay relaxed and hold your position after breaking the shot.
• 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 below, the 5th shot was the highest in the group–probably because of fatigue or lack of concentration.
The NBRSA has liberalized its rules regarding front sandbags. Until this year, NBRSA rules required that benchrest competitors be able to lift their rifle fore-ends freely from the front bag. Accordingly, front bags could not “capture” the forearm or hold the gun down (i.e. keep it from rising). In order to meet this requirement, “legal” bags had straight sides that didn’t stand too far up.
Now the NBRSA rules have changed. You no longer have to be able to lift the gun up freely from the bag without interference. It’s now permissible to have a bag that offers some up/down retention. Check out this new bag from Edgewood Shooting Bags. Call “The EDGE”, it offers taller side sections that can hold the fore-arm in place and counter torque.
Edgewood’s designers state: “There are a couple of [NBRSA] rule changes for 2017. The change we found most intriguing was that the requirement of being able to lift your fore end freely from the front rest has been removed. So, we came up with a new design with super tall ears which will allow the innovators to push the envelope. Let’s see what you can do with these…”
We expect this new type of front bag will help stabilize short-range benchrest rifles, particularly in the 10.5-lb Sporter and Light Varmint classes. But we expect the biggest gains will be had with the big-caliber rifles used in Mid-Range and Long Range benchrest competition. In the 1000-yard game, heavy-recoiling 7mm and .30 caliber cartridges are popular with many shooters. These big guns generate considerable torque despite their ample weight. We predict these “super-sized” front bags will reduce both hop and rolling motion (torque) in the big guns.
We also expect that some varmint hunters will experiment with high-sided front bags that wrap around the fore-end. Such front bags may prove a real boon for guns with narrower, sporter-style fore-ends. And it would be interesting to see if this kind of tall-sided bag design will be incorporated into portable sandbags for the PRS game. We shall see…
Rule Change and Product Tip from EdLongrange. Product Tip from Boyd Allen. We welcome reader submissions.
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Here’s some benchrest advice that can help you reduce vertical and shoot tighter groups… without spending another penny. Next time you go to the range, experiment with the position of your rifle on the front rest, and try a couple different positions for the rear bag. You may find that the rifle handles much better after you’ve made a small change in the placement of your gun on the bags. Recoil can be tamed a bit, and tracking can improve significantly, if you optimize the front rest and rear bag positioning.
Balance Your Gun BEFORE You Spend Hours Tuning Loads
In the pursuit of ultimate accuracy, shooters may spend countless hours on brass prep, bullet selection, and load tuning. Yet the same shooters may pay little attention to how their gun is set-up on the bags. When you have acquired a new rifle, you should do some basic experimentation to find the optimal position for the forearm on the front rest, and the best position for the rear bag. Small changes can make a big difference.
Joel Kendrick, past IBS 600-yard Shooter of the Year, has observed that by adjusting forearm position on the front rest, he can tune out vertical. He has one carbon-fiber-reinforced stock that is extremely rigid. When it was placed with the front rest right under the very tip of the forearm, the gun tended to hop, creating vertical. By sliding the whole gun forward (with more forearm overhang ahead of the front sandbag), he was able to get the whole rig to settle down. That resulted in less vertical dispersion, and the gun tracked much better.
Likewise, the placement of the rear bag is very important. Many shooters, by default, will simply place the rear bag the same distance from the front rest with all their guns. In fact, different stocks and different calibers will NOT behave the same. By moving the rear bag forward and aft, you can adjust the rifle’s overall balance and this can improve the tracking significantly. One of our shooters had a Savage 6BR F-Class rifle. By default he had his rear bag set almost all the way at the end of the buttstock. When he slid the rear bag a couple inches forward the gun tracked much better. He immediately noticed that the gun returned to point of aim better (crosshairs would stay on target from shot to shot), AND the gun torqued (twisted) less. The difference was quite noticeable.
The important point to remember here is that each rig is different. One gun may perform best with the front rest right at the tip of the forearm (Position ‘D’ in photo), while another gun will work best with the rest positioned much further back. This Editor’s own 6BR sits in a laminated stock that is pretty flexy in the front. It shoots best with the front rest’s sandbag located a good 6″ back from the forearm tip (position ‘A’).
A small change in the position of the forearm on the front rest, or in the placement of the rear bag, can make a big difference in how your gun performs. You should experiment with the forearm placement, trying different positions on the front rest. Likewise, you can move the rear bag back and forth a few inches. Once you establish the optimal positions of front rest and rear bag, you should find that your gun tracks better and returns to battery more reliably. You may then discover that the gun shoots smaller groups, with less vertical dispersion. And all these benefits are possible without purchasing any expensive new gear.
Does your rear sand-bag get lumpy or lose its shape during transport? Are your bag ears starting to sag or get mis-aligned? Well the clever Italians have a solution for you.
Varide Cicognani, an Italian webstore specializing in competition shooting accessories, offers a cleverly-designed bag transport/storage caddy for rear sand-bags. Cicognani’s Portacuscino Model TFC-P is designed to keep your rear bag “in shape” during transport and storage. The TFC-P features aluminum top and bottom brackets, connected with threaded rods. A wedge under the top bracket fits between the bag ears. The top bracket has a convenient carry handle. The whole unit (not including bag) weighs just 13.4 ounces (680 grams). The price is € 49, or $65.99 at current exchange rates. For more information, visit www.VarideCicongnani.it.
Product Tip by Boyd Allen. We welcome reader submissions.
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You’ve heard of Heavy Metal, maybe even Heavy Water, but what about Heavy Sand? Every serious shooter should know about Heavy Sand for benchrest sandbags. Heavy Sand can weigh up to twice as much as ordinary silica sand (sold as “Play Sand”). By filling your rear bag with Heavy Sand rather than silica sand, you can nearly double the bag’s mass, and that can translate to better bag performance. A heavier bag resists movement and stays aligned better during recoil. If your bag moves during recoil, or becomes misaligned from shot to shot, that can alter your point of impact and open up your groups. Adding weight to your rear bag is a simple, cost-effective way to shoot more consistently, with greater overall accuracy.
Jason tested and compared four kinds of sandbag fillers: Zircon, Chromite, Riverbed Sand, and ordinary Play Sand. Zircon is the heaviest type of sand readily available to shooters, followed by Chromite. Zircon is 98% heavier than Play Sand, while the black Chromite sand is 94% heavier than Play Sand. Riverbed Sand, commonly sold in pet stores as “Reptile Sand”, is less dense, measuring about 55% heavier than Play Sand.
Increase Bag Weight Up to 10 pounds
Compared to silica sand, how much extra weight can Heavy Sand (Zircon, Chromite, Riverbed) add to your sandbag? Up to 10 pounds, depending on the size of your rear bag. Check the chart below for the specifics. By filling a standard bunny ear bag with Zircon (vs. silica sand), you can increase bag weight by about 5 pounds. A super-sized BigFoot bag can gain 10 pounds in overall weight when filled with Zircon as opposed to silica sand.
To learn more about Heavy Sand (and where you can buy it), read Jason’s comprehensive Sand Comparison Article. It includes photos of the different sand types and links to Heavy Sand vendors, such as R.W. Hart (Zircon) and Sinclair International (Chromite).
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Danny Biggs is one of the nation’s most successful F-Class shooters. A two-time (back to back) National Champion in F-TR Class, Danny also finished third in Open Class at the 2010 National Championships. Notably, Danny’s X-count of 67Xs, the highest of all competitors, was 10 Xs higher than 2010 F-Open winner Derek Rogers.
Mat with ‘Donut-Hole’ Cut-Out for Rear Bag
Danny is a very savvy competitor, to say the least, and he brought some innovative gear with him to the Nationals. Along with his height-adjustable Sinclair wide-base bipod, Danny used a cleverly modified shooting pad and Edgewood rear sandbag. Danny’s “donut-hole” mat featured a cut-out in the middle, allowing him to place his rear sandbag directly on the ground. This helps stabilize the bag no matter what the ground surface or slope. With the bag sitting directly on the ground, it’s less likely to slide or rotate.
In addition, Danny’s rear bag is raised up via a thick rubber base or “foot”. The fat base, which appeared to be hard rubber, is secured via metal tabs that clamp on to the hard leather bottom of Danny’s Edgewood rear bag. The Edgewood bag has a lip around the bottom that provides a natural attachment point for the metal tabs.
Inexpensive MidwayUSA Shooting Mat
Danny uses an affordable shooting mat — the basic 67″ L x 26.75″ W MidwayUSA shooting pad that retails for $49.99. FYI, MidwayUSA’s larger Pro Series Competition Shooting Mat is on sale right now for the same $49.99 (sale price through May 31, 2012). Sized 73.5″ long x 35.5″ wide, this deluxe, khaki-colored mat rolls up into an 8.5″ Diameter “sausage” for transport or storage. The mat has rubberized elbow and knee pads; the mat is about .535″ thick at the knee and elbow pads. By comparison, the standard MidwayUSA Shooting Mat is only 0.335″ thick on the pads. Both standard and Pro Series mats have corner grommets allowing the mat to be staked down in high winds. These mats both have a carry handle and a shoulder strap.
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The IBS recently announced that it would allow AR-platform rifles to compete in local IBS benchrest matches in their own class. If you plan to campaign your AR in this new class, you should definitely add a 3″-wide front sled and some kind of rear bag-rider to your gun. Without a flat fore-arm “sled” and rear bag-rider, ARs tend to be very wobbly, and the standard rear stock (with sling loop in place) is terrible in a rear sandbag.
Robert Whitley’s AR-X Enterprises has just what you need to improve your AR’s bench behavior. AR-X sells precisely-fitted Delrin bag-riders, crafted expressly for ARs by Evolution Gun Works (EGW). The 3″-wide front bag rider (aka “sled”) features a “twin rail” design and attaches to a tubular fore-arm via a swivel stud. The rear bag-rider mates to the bottom of a standard AR stock and attaches via the rear sling swivel anchor. This provides a smooth, straight surface to ride the bags.
These Delrin EGW bag-rider units were originally designed and prototyped for AccurateShooter.com’s 20 Practical AR project rifle. We tried many different designs, and the final production versions really work — as you can see in the video above. The AR bag-riders cost $40 front and $40 rear, or $75.00 for the set of two. To order, visit 6mmAR.com, or email Robert Whitley: rcw3 [at] erols.com .
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Back in the old days, Pat McMillan told me: “You can not have two bags filled so hard that you gun bounces on them in the process of firing round at your target, especially if you have a rig with a very flexible stock. The bags must be set up in a manner for them to absorb the initial shock of the firing pin moving forward and igniting the primer. 
1. Align Front Rest and Rear Bags. We see many shooters whose rear bag is angled left or right relative to the bore axis. This can happen when you rush your set-up. But even if you set the gun up carefully, the rear bag can twist due to recoil or the way your arm contacts the bag. After every shot, make sure your rear bag is aligned properly (this is especially important for bag squeezers who may actually pull the bag out of alignment as they squeeze).
3. Weigh Your Charges — Every One. This may sound obvious, but many folks still rely on a powder measure. Yes we know that most short-range BR shooters throw their charges without weighing, but if you’re going to pre-load for a club match there is no reason NOT to weigh your charges. You may be surprised at how inconsistent your powder measure actually is. One of our testers was recently throwing H4198 charges from a Harrell’s measure for his 30BR. Each charge was then weighed twice with a Denver Instrument lab scale. Our tester found that thrown charges varied by up to 0.7 grains! And that’s with a premium measure.
5. Check Your Fasteners. Before a match you need to double-check your scope rings or iron sight mounts to ensure everything is tight. Likewise, you should check the tension on the screws/bolts that hold the action in place. Even on a low-recoiling rimfire rifle, action screws or scope rings can come loose during normal firing.
Does your rear sand-bag get lumpy or lose its shape during transport? Are your bag ears starting to sag or get mis-aligned? Well the clever Italians have a solution for you.
Mat with ‘Donut-Hole’ Cut-Out for Rear Bag
