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A Competitive Yet Affordable Target Rifle

Posted: Sat Aug 24, 2013 11:49 pm
by Bob Smalser
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Once a competition marksman, match armorer and coach for the Army, I enjoy spending my Saturday mornings coaching juniors in a county-wide program run by the Kitsap Rifle and Revolver Club, teaching competitive shooting to youngsters between ages 8 and 18 (photo left above). As the pool of families active in shooting sports diminishes with urbanization, a surprising number of opportunities exist for talented youngsters to win college athletic scholarships, service sponsorship (the right-hand photo is an Army-run clinic for advanced juniors) and ultimately even Olympic Team berths in the various small-bore and air rifle disciplines. While our program has a selection of vintage, entry-level target rifles suitable for the younger juniors (mostly WWII-era Remington 513’s), older and exceptionally talented youngsters rapidly reach the point where they need their own rifle. As most of our parents work at the local naval bases and shipyard or in the timber or construction industries, this poses a problem as high-end rifles like the Anschutz below that provide the best chance for holding a talented youngster’s interest and ultimately winning scholarships cost upwards of $4000 new and $2500 used.

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While this Anschutz Model 1913 “Super Match” may look like a space gun, and the action, sights, trigger, barrel and their mountings are certainly “best-quality”, they are still 1890’s technology with some later refinements that have been equaled in many rifles. What makes this rifle the best of the best is its precision barrel and mountings to optimize barrel harmonics (reducing sensitivity to differences in ammunition and other conditions) and its fully-adjustable grip, cheek piece and butt, allowing optimum hand and head placement in each shooting position. Ideally, the grip, hand and shoulder pressure should be perfectly consistent and the eyes should be dead level when firing in each of the prone, sitting, kneeling and standing positions, because as the rifle fires, the brain anticipates losing control for an instant and the balance mechanisms in the inner ears cause the body to move so as to level itself. This can throw the shot off slightly, especially with slow-moving target bullets and pellets that take a while to leave the barrel. While not as critical during casual shooting or with higher velocity rifles, at this level of competition the challenge is to reduce the probability of making a bad shot across hundreds of scored rounds fired in succession, and every advantage counts, head position being one of the most important.

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Fortunately (for shooters if not taxpayers), in the late 1980’s the Army contracted with Kimber of Oregon for 15,000 target rifles to be used as trainers for Junior ROTC, and for a number of reasons never used them. These were built to a standard of consecutive shot groups never larger than .700 inches at 50 yards, and are made with components sufficiently close to or equaling the quality of the $4000+ Anschutz. Their limitations are they were built for children, have short barrels and inadequate stock adjustments, and are somewhat heavy, given the intended audience (although they weigh less than the Anschutz above). As surplus, these new rifles were turned over to the government’s Civilian Marksmanship Program and are available to qualified competitors and clubs for $425 each. I ordered three of them with the intention of converting them into competitive yet affordable high-end target rifles available to parents at cost, and this article is a tutorial on how you can do the same. The techniques I show are all oriented to minimizing shop hours and costs, and are applied in priority. The first steps are to modify an already-accurate rifle to fit the shooter for 3-position competition across a hundred record shots in a row, with attendant ease of adjustment and maintenance. Later as students progress, I’ll add accuracy refinements like pillar bedding and bolt, trigger and barrel modifications so the shooter never progresses to the point where he or she can hold tighter than the rifle can shoot.

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After removing the factory-applied preservatives and minor surface rust from poor storage, I begin with the stock. (The rust I encountered was merely surface flaking limited to the sights and few recesses and was easily removed using Kroil penetrating oil and a small bronze brush.) The Kimber uses simple plastic spacers to adjust length of pull (LOP) from 12 to 13 ½ inches for growing children. I’ll replace these with a 4-Way Buttplate with Hook from Alex Sitman of Master Class Stocks in Bellwood, Pennsylvania ($165.00), the least expensive of the target buttplates that adjust for length, cast, toe-in/out and height. I’ll also retain the stock’s design features so it can be easily put back into original configuration should subsequent owners ever want to use it to train younger children or are concerned about collector value. I chose this option because although the DV buttplate has a large LOP adjustment, I don’t want to cut the stock much shorter than it already is, as the length of the comb where it contacts the cheek is already at close to the minimum length for an adult firing offhand.

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The first step is to drill the new base plate to match the stock’s existing buttplate screw inserts. I use the original buttplate as a template to centerpunch the holes, and set the depth stop on the drill press to drill the countersinks first, so the hole and countersink allow the plates to nest perfectly flush with each other.

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Because this plate is slightly narrower than the Kimber stock and I want to avoid major work reshaping the stock from the wrist rearward, I’ll make a walnut plate to fair the transition between stock and butt plate while also protecting the stock’s end grain from chipping. Layout of the plate is straightforward, using the drilled base plate as the template to mark hole locations.

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The hole in the plate for the buttplate extension is bored plumb on the drill press and its shoulders serve as an index to freehand the deep hole for the buttplate extension. Set the drill press up to do this if you lack experience. An L-shaped jig can be fabricated from half-inch plywood to clamp to the edge of the drill press table to hold the stock vertically.

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The final result is a serviceable 4-way buttplate with a minimum LOP of 13 ½” for a small adult, yet with the capability of putting the rifle back into its original buttplate spacer configuration for children. This stock is ready to use for most competitors of average body build.

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An alternative of greater benefit to shooters (especially those with long necks) at the expense of spoiling any future collector value is to shorten the stock and install adjustable comb hardware. Here I’ve taped the stock to prevent chipping by the saw and to aid layout. I remove 5/8” of the stock’s length using a large miter saw, reinstall the aluminum base plate assembly and lay out the locations of holes and their depths to decide where to cut the comb. The threaded inserts anchoring the buttplate bolts remove and reinstall easily using an Allen wrench, and are sized to match the existing bolt hole, precluding the need for drilling new pilot holes. To insure all cuts are plumb, I mount the stock to a scrap of sacrificial doorskin using shims and tape, and will cut through the doorskin as well as the stock. I’ve also used heavy cardboard and spray adhesive for this purpose of squaring and plumbing odd-shaped workpieces for cutting…it’s the easiest method to insure perfect cuts on expensive wood. Here I’ve chosen Graco adjustable comb hardware from Brownell’s that easily adjusts using Allen wrenches for cast as well as height. This hardware is more often seen on shotguns than rifles, but at $28 to gunsmiths, it’s by far the most economical solution. These also come with the posts mounted to a plate instead of to disks, but the disks and bushings are perfectly sized to match common Forstner bits and take less shop time to install.

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The comb cut is laid out to fall between the holes for the upper buttplate screw and stock extension tube, which is also the optimum place to cut the aluminum base plate. This hardware is typically mounted without cutting the buttplate, but as mentioned previously, the comb on these stocks is already quite short for use by adults in the offhand position, and the base plate can be cut without harming its function to lock the stock extension tube in place. Most bandsaws will cut aluminum, otherwise just use a fine-toothed hack saw blade followed by cleanup with a fine, single-cut file to cut the plate. Insure your resulting comb has sufficient depth to mount the bushings and boreholes necessary to accommodate the full depth of the posts without drilling through the comb top. I mark the centerline of the comb and freehand drill those holes plumb to the surface of the cut using Forstner bits. Then I place the bushings, posts and post screws into the comb holes to mark the centers of the matching base holes in the stock by holding the comb in place and tapping the comb top with a soft mallet, followed by a proper centerpunch.

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The disk-shaped post bases and matching bushings are mounted to the stock using epoxy in stages. First the disks and bushings are checked to insure they are flush to the surface of the cut and the hole depths adjusted as necessary. The disk slots and the posts and their mounting screws and nuts are coated with paste wax to insure any epoxy slop won’t stick. Then a small amount of unthickened epoxy is applied to only the sides of the bushing holes, and the hardware and comb assembled in its lowest position for curing in place. This stage tacks the hardware in place in perfect alignment. After curing, double check to insure the comb moves freely in the manner the hardware was designed for. If adjustments are required, use a hot soldering iron to heat the offending disk or bushing to around 180 degrees. This will soften the epoxy and allow the hardware to be easily moved (or even removed), with no harm to the epoxy bond once it cools. Then after everything is cured and aligned, another coat of unthickened epoxy spatula’d around the edges of the holes and gently warmed using a heat gun will thin the second coat to the consistency of water, allowing it to seep into small spaces to thoroughly glue the hardware to the wood. The epoxy can also be dyed to match the wood using pigments made for that purpose. Here I’m using West System 5:1 boatbuilder’s epoxy, but any marine epoxy or Brownell’s Acraglass will work fine if you avoid the quick-setting hardeners and gel epoxies that can’t be thinned using heat. After curing I carefully drill and tap the comb for the 10-24 X 1/4 set screws that hold the comb at the desired height. Insure you don’t mount these too close to the cut to avoid splitting in use.

While I’m doing stock work, I’ll mill ventilation slots along the barrel channel so the barrel heats and cools evenly during long strings of record shots. I’m copying Anschutz here, but I think it’s a good idea and it’s a relatively easy and inexpensive modification.

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First I make a carefully-measured jig for the router. These must be substantial, as the pressures involved using a large plunge router are heavy and the consequences of error severe.

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The stock is taped for layout and to prevent chipping, the slots laid out so as to minimize short grain and thin edges prone to split with rough handling, and fences are set to index both edges of the router to eliminate the possibility of error. Note the thin, doorskin shim under the tip of the forearm in the jig to insure the cuts are plumb. The forearm appears to have parallel sides, but they are actually gently tapered.

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I ease the edges using files and also scrape a few thousandths out of the barrel channel to insure the barrel remains free floating in use. Last, I apply a coat of Truoil to all bare wood as a seal to retard moisture absorption. Even after all that preparation, the cuts aren’t as perfect as I’d like – for the next stock I’ll invest in a fresh 5/16” carbide router bit and redo this one while I’m at it.

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Before final assembly, I adjust the trigger from the 4lbs set at the factory to the 3lb minimum for competitions conducted under NRA Rules. The rifle is shipped with a complete user’s manual and also the technical manual page that describes trigger and sear adjustment. Note I use an orange-colored plastic dummy round in the chamber to protect the firing pin when dry-firing. A major disadvantage of these rifles is that the contract was terminated before repair parts were manufactured, and none are available except from the occasional parted-out rifle found on internet auction sites. Lose or break a hard-to-find part, and you may have to fabricate one from scratch. Accordingly, I maintain a “saved search” for Kimber 82 Government parts on all the major auction sites to receive email notifications when spare parts become available.

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Because of the short 25” barrel, I install a barrel extension (bloop tube) to bring the barrel length to the 30” maximum allowed in competitions conducted under International rules. The further the distance between front and rear sights, the easier the alignment, and five inches of increased sight radius is worth the investment. Jim Beck of Champion’s Choice Shooter’s Supply in LaVergne, Tennessee sells an 8” tube with mating collar for $66, and for another $10 will machine the collar to fit the .952” barrel diameter at the muzzle. I also buy their adjustable palm rest for offhand shooting ($34), and both their right-hand and left-hand contoured “Jumbo” front hand stops ($32), which I much prefer to the undersize hand stop that comes with the rifle, as there is less pinching of the supporting hand to distract new shooters not yet used to slings.

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The stock bloop tube is 1 ¼” too long to meet the 30” maximum barrel length (measured to the bolt face using a cleaning rod against the closed bolt), so I cut it using hack saw and facing cutter and drill and tap the necessary 6-48 hole to remount the mounting block for the front sight.

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I don’t work with factory-new firearms very often, and was surprised that reassembly of the action-to-stock bolts was unnecessarily difficult. This could have damaging consequences if assembled by a child, and examination revealed the typical burring caused by drilling and tapping wasn’t cleaned up at the factory before assembly. So I removed the burrs using a hand-turned, 45-degree countersink and a fine-toothed pillar file and chased the threads with a ¼-28 tap. Note that the recoil lug mounts in a dovetail and is held in place by a set screw. This design allows some movement of the action in the stock to insure the barrel remains free floating.

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After torquing down the stock bolts, I double check to insure the barrel is free floating along its entire length, and is centered in the barrel channel. Discrepancies here can be adjusted by moving the recoil lug above, or in serious cases of stock warp, by removing wood from the barrel channel. I prefer to snug the locking-lug bolt down tight and apply a bit less torque to the rear action bolt so there is no danger of distorting the action, but you can play with various bolt torques as you shoot to see if they make any difference in the rifle’s performance. Pillar bedding the action is a further enhancement that is relatively inexpensive when the shooter reaches the point where minor improvements in accuracy will make a difference. Although I applied a thin coat of oil-based sealer to the inletting and fresh stock cuts I made, I don’t bother improving the stock’s cosmetics, as they don’t affect function.

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The final result is an attractive rifle with that traditional forged-milled-steel and quality-walnut look I’ve always admired, but the proof comes in how well it shoots. The limiting factor in whether a rifle will consistently hit a pencil point at 50 feet or a dime at 50 yards is generally the ammunition, not the rifle, and there have been a number of user accuracy tests done with these surplus Kimbers, the results of one of the most thorough by Sergey Solyanik of Seattle are shown below. These are 5-shot groups fired from a bench rest at 100 meters using a 36-power scope, minimizing all factors except the rifle and brand of ammunition (and Sergey’s ability to dope wind). Measurements are in inches, and keep in mind that the most difficult target used in small-bore competition is the 50-meter International target with a .409 inch 10-ring…half the distance of this test:

Lapua Midas: .80, .78, 1.08, 1.12, .73, .83, .94, .66, .92, .72
Wolf MT: .94, .60, .84, 1.22, 2.27 (1 flier), .71, .62, .60, .67, .99
Federal Target: 1.13, 1.09, 1.21, .59, .86, .80, 1.12, 1.17, 1.04, .91
Federal Ultra Match: .83, .50, .71, .90, .78, .83, .98, .40, .46, .53
Eley Tenex: .64, .62, .65, 1.45, .99, 1.00, 1.42, .89, 1.81 (1 flier), 1.24
CCI Standard Target: 1.79, .65, 1.18, .25, .50
CCI Blazer: .91, 1.26, 1.16, 3.02 (1 flier)

Lapua Center-X is reported to also work well. All these results exceed the performance capabilities of most teenagers. The results for the Federal Ultra Match and Lapua Midas exceed the capabilities of many Olympians. While sacrificing some convenience and precision in stock adjustment with the upgraded Kimber compared to the Anschutz 1913, there is little risk that junior shooters will reach the stage of proficiency where they can hold tighter than this rifle can shoot….and for a total bill under $750 as opposed to $4000+.

Bob Smalser, July, 2013.
http://www.wkfinetools.com/contrib/bSma ... -index.asp

Notes:

Jim Beck of Champion’s Choice Shooter’s Supply in LaVergne, Tennessee. Sight extension $33, collar $33, and palm rest $34. Machining to fit a .952 muzzle $10.

Alex Sitman of Master Class Stocks in Bellwood, Pennsylvania. DV 4-way Buttplate with hook. $165.

Brownells Gunsmithing Supply in Montezuma, Iowa. Graco adjustable comb hardware $28-44.

Weights are 10.75lbs for the stock Kimber, 11.2lbs for the Kimber as built, and 12.76lbs for the Anschutz 1913 in aluminum.

Posted: Tue Sep 17, 2013 7:13 pm
by Roadthing
Nice Job, I have done a few of these into prone rifles. They do make a good starter rifle.

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Posted: Tue Sep 17, 2013 9:10 pm
by Bob Smalser
Yes. I've seen yours and am impressed. I'm going to copy your grip and comb profiles a bit. For the group that uses them I can't make them left or right handed but am not happy with the stock grip position and intend to thin and add some angle on the next one.

Thx.

Posted: Fri Nov 15, 2013 8:56 am
by Gleedaniel13
How much is the price? I want to promote it here on my country and hopefully it will be in demand.

Posted: Mon Nov 18, 2013 8:34 pm
by Bob Smalser
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After a few months of use, the (relatively inexpensive) Kimbers modified for position use aren’t very popular, nor do the youngsters shoot them as well as the most popular rifle, the (very expensive) Anschutz 2013. Analyzing why, although the Kimber is almost two pounds lighter, it isn’t balanced as well, being rather severely muzzle heavy.

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Testing the available Annies on a fulcrum, the 2013 and also the 54 and 1413 balance right at the barrel end of the receiver ring, while the Kimber’s balance point is an inch and a half further forward.

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So I’ll adjust the rifle’s balance using some lead in the butt, first measuring how much I need to achieve the balance point I’m looking for…

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…then adding around a half ingot more. While I have it apart, this is a good point to steam out that ugly scratch and clean up and protect the stock with some topcoats of finish. When I’m done, I’ll reassemble the rifle and drill out the excess lead to achieve the balance point I’m looking for.

Posted: Sat Nov 23, 2013 8:16 pm
by BobGee
Very, very interesting Bob (and Roadthing). I don't have a need to go the whole hog as you have but it's given me some good ideas for what I could do to improve my own rifle.

Bob

Posted: Fri Nov 29, 2013 11:16 am
by Tim S
Bob,

very interesting post. I do have one question. You mention cutting down the extension tube to meet the 30in maxiumum barrel length permitted under International rules. Is this a US-NRA rule? Current ISSF rifle rules only specify a maximum barrel length for 300m Big bore rifle, and 10m air rifle; tube length for 50m smallbore is unrestricted. The old UIT Standard rifles did limit barrels to 30in, but these were replaced by the Sport Rifle in 1997.

Tim Slater

Kimber M82G

Posted: Wed Jan 15, 2014 10:02 pm
by James Storm
I found your article on the upgrading of this rifle extremely interesting and well thought out. To it I would strongly recommend the article by W. Joe Ruth in the September 2012 issue of Precision Shooting (no longer published) regarding his evaluation, upgrades, and smithing of this gun. I have approached the stock from a somewhat different direction, fabricating an entire stock and its furniture from Home Depot oak. It is far less expensive, but not as elegant looking as your modifications. I noted that the kids in your group didn't shoot the modified Kimber as well as the Anschutz and I wondered if they unconsciously performed less well on the modified M82 because they felt that the less expensive rifle must be inferior, regardless of its objective superior performance. Thanks again for your article.