ARs in PRS? Yes PRS has a “Gas Gun” division. And frankly, shooting a PRS match is one of the most fun and challenging things you can do with your Black Rifle (Beto O’Rourke notwithstanding). Since the early days of the PRS, Gas Gun shooters have wanted to play. Recognizing the interest among semi-auto shooters, the PRS now offers a Gas Gun Series for semi-auto rifles such as AR15s and AR10s. The Gas Gun Series started in 2017, and has quickly become quite popular.
Photo Credit Michael Cage.
Gas Guns to 800 yards — Yes there are targets down there somewhere.
PRS Gas Gun Series Rules
For the new PRS “Gasser” Competition, the PRS developed rules on gun types, scoring, match timing, penalties, safety and other key topics. CLICK HERE for Full PRS Gas Gun Series Rules.
Open Division: Open Division rifles will not exceed a caliber of .30 or a velocity of 3,200fps. A match DQ will result any rounds over the speed limit of 3,200 fps (+/- 32 fps for environmental factors and equipment discrepancies). Match Officials may request at any point during a match that a competitor fire their rifle through chronograph. If the bullet exceeds the 3,200 fps speed limit, the shooter will receive an automatic match DQ. [“For Ammo in Open Class, 6mm and 6.5mm Creedmoor are popular.” — John Parker, SSUSA]
Tactical Division: Tactical Division: Intended to allow competitors the opportunity tocompete using traditional military and law enforcement caliber. This promotesActive Duty military and law enforcement competitors use of their Service and Department issued rifles. Tactical Light Division rifles are restricted to 5.56 NATO/.223 Remington and 7.62 NATO/.308 Winchester calibers only. .223 Bullet weight cannot exceed 77 grains and muzzle velocity cannot exceed 3,000 fps, .308 bullet weight cannot exceed 178 grains and muzzle velocity cannot exceed 2,800 fps. No modified wildcat rounds permitted to shoot in the Tactical Divisions. Tactical Division shooters will shoot the exact same COF as Open Division shooters. [NOTE: This division now replaces the previous Tactical Light and Tactical Heavy divisions.]
Scoring and Penalties
The Gas Gun Series utilizes a time plus penalty based scoring system for all match scoring. This means your score is your total combined time on all stages plus any penalties you may have accrued.
Stage Course of Fire and Targets
No more than 50% of the stages at a match can utilize an unlimited round count. At least 25% of the targets in Gas Gun Series match must be 2 MOA or smaller. Maximum distance is 800 yards.
The preferred rifle color choice at the first PRS “Gasser” Match was definitely black…
Gas Gun Match Loads — Short Range vs. Long Range
“The .223/5.56 [Tactical Light] guns had some lag time waiting on shot impacts. I believe the long-term solution may be to find a light and fast load for closer stages for near-instant reaction time and use a heavy load for the long shots to see splash and get the target to move a little more.” — Sean Murphy, Nightforce
Gear Options for PRS Gas Guns
There are many buttstock options for ARs. For the PRS game, we like the Magpul PRS stock. This features a quick-adjustable cheek-piece and butt-plate — allowing you to easily adapt head position and LOP for your discipline of the day. (You may want a different LOP for prone shooting vs. bench shooting). The Magpul stock works well in a rear bag.
We recommend something like the Blackhawk grip which is more comfortable than the typical grips supplied by most black rifle makers. Up front, you’ll want a handguard with adaptability. Shown is a handguard with Picatinny rails on top and on both sides, affording lots of options. We might move one of the rails to the bottom, however, so it could be used for a bipod mount.
Add Your Favorite Premium Barrel:
PRS with a Gas Gun — Gavin Gear’s Experience
Thinking of trying out the Precision Rifle Series, starting off with a gas gun? Well Gavin Gear of UltimateReloader.com did just that, competing in his first-ever PRS match up in Washington State. With its timed stages (some just 90 seconds long), Gavin learned that PRS is about speed as well as accuracy. As a PRS newbie, Gavin found the competition fun but challenging. Gavin’s account of his experiences, set forth in two articles with accompanying videos, will help other novice PRS competitors prepare for PRS-type matches and assemble the right equipment.
This video has cool Aerial Drone footage, and in-depth explanation of stages:
Gavin enjoyed his first match: “Overall, the match was more fun and more laid back than I thought it would be. The guys in our squad were all really helpful, and even loaned me gear to try out when they noticed my gear wasn’t right for a particular shooting activity. One such case was when Ken Gustafson (of KYL Gear) offered to loan me one of the bags he had made. Below you can see me shooting off the infamous unstable tippy tank trap with a KYL Gear bag, and I’ll have to say [the bag] was amazing. It helped me lock down my rifle and get on target. What a great feeling!”
Forum member Kevin (aka “N10Sivern”), revealed he needs some help with a compulsion — a compulsion to keep buying more and more guns and ammo. Particularly ARs, all shapes and sizes of ARs. Way too many ARs. You could say he has an ARdiction….
In a Forum Thread, Kevin posted: “I may need an intervention. Trying to clean my office and pulled this stuff out. I’m missing an AR10 lower somewhere and an AR15 upper. I’ll find them before the day is done. I have a big box full of parts as well, and 4 barrels still in the cardboard tubes. Sigh. This is gonna be a lot of Cerakoting for me.”
Another Forum member said: “For the love of God, man. Delete this thread lest you be accused of hoarding!”
Kevin replied: “I guess I am hoarding a little. But it’s good hoarding right?”
And then he posted this “Mail Call” photo:
Kevin’s caption: “It only gets worse. Mail Call today: 20″ .308 Ballistics Advantage barrel, 26″ Savage 25-06 barrel, 700 pieces of .38 special, 300 pieces of .357 magnum, 500 pieces .308 Win, gas tube, Hornady Modified Case Gauge. I have more crap on the way too.”
Forum Member’s Chime In…
Kevin’s “Need Intervention” post drew plenty of comments from other Forum Members:
“God! It is so refreshing to see that my illness is widespread with little hope (or desire) for a cure. I smiled reading each post.” — Gary0529
“You know you have a problem when you open a drawer and find components you forgot you bought.” — JoshB
“It’s not hoarding if you intend to use it. Says he who has 12,000 primers.” — Uthink
“I guess I’ll go ahead and volunteer to help you with your obviously much needed intervention… send me the pictured items and then you’ll no longer have to deal with those nasty temptations. Just think about it, you’ll have less clutter in your office plus you’ll not have to fret over the need for any cerakoting either. I’m just one human being volunteering to help out another fellow human being who needs help!” — PikesPG
Trigger images from PrimaryArms.com, which sells all the triggers reviewed here: Geissele, Elftmann, Timney, and ALG Defense.
Are you thinking of upgrading the trigger system for your AR-platform rifle? There are dozens of options available, from $45 up to $300. Thankfully, Brownells has created video reviews of some of the more popular AR trigger options from Timney, Geissele, and ALG Defense. And we included a video review of the highly-regarded Elftmann Match Trigger. If you want the best solution for Service Rifle competition, you might favor the Geissele. For ease of installation, it’s hard to beat the Timney, a “drop-in” module. Like the Timney, the super-smooth Elftman is a drop-in module. At $249.00 it’s pricey, but it is one of the best AR triggers out there. If you’re on a tight budget, the best “bang for your buck” may be the “Perfected Mil-Spec” ALG which starts at around $45.00.
Multiple AR Triggers, including the Elftmann and Geissele, Are Reviewed in this Video
Though pricey ($249.00 at PrimaryArms.com), we really like the Elftmann AR trigger. It combines the best of both worlds — the precision and smoothness of the Geissele with the Timney’s ease of installation. This single stage trigger is user-adjustable from 2.75 to 4 pounds pull weight. It is offered with either straight or curved trigger blade. Primary Arms says: “The amazingly short take-up, glass-rod crisp break and [near-zero] over-travel can be compared to the finest custom 1911 triggers.”
Geissele Enhanced Two-Stage Trigger
Geissele makes a variety of quality AR trigger sets both single-stage and two-stage. Many High Power competitors like the two-stage Geissele trigger. This delivers a repeatable, controlled pull through the first stage with a very clean break in the second stage. The Super Dynamic Enhanced Trigger, shown above, features a distinctive, trigger blade. Reviewer Thomas Conroy says: “The flat surface is very easy to press against. Both stages are light and very distinct.”
Timney Drop-In Trigger Module
This trigger module is available for both the AR15 and the AR10 platform (see above video). Timney triggers are easy to install and come with multiple pin size and pull-weight options. Reviewer Thomas Conroy confirms that the single-stage Timney “breaks cleanly and crisply. This trigger is modular, meaning that the trigger, sear, hammer, and spring are all encased in a bright, shiny yellow aluminum housing.”
ALG Defense Trigger — Higher-Quality Basic AR Trigger
According to Thomas Conroy, ALG triggers “are the perfected version of the standard, non-adjustable mil-spec original trigger. They have the same geometry, but are made to higher quality standards, and come with … hardened and smoothed-out sear contact surface to eliminate all grittiness.” These are also offered in a nickle-boron coated version. Available for under $45.00, the ALG is a well-made, low-cost option for shooters who want a better factory-type trigger system.
For More Information about These Triggers
Learn more about Geissele, Timney and ALG triggers, plus two more AR trigger options (CMMG and Rock River Arms) in a Trigger Comparison Review by Thomas Conroy on Ammoland.com.
Ever wish you could look inside your rifle, to see how the trigger and fire-control system work? Well now that is possible with the magic of 3D computer graphics. Modern software allows detailed “cutaway” side-views (see below), as well as 3D views with 360° rotation. The software can also provide X-Ray-type views into the gun’s internals — as you can see above. And computer animation can show the complete firing process from trigger pull to chambering of the next round.
Rem 700 Cutaway View from Right Side
This article covers two different animations — a bolt-action, and a self-loading “gas gun”. The first video features the popular Rem 700 action, probably the most successful American bolt-action ever created. The second video offers a lengthy exploration of the AR15/M16 platform.
READERS — Take the time to watch these videos! The Rem 700 animation is really outstanding! EVERY bolt-action shooter should watch this video all the way through.
Cutaway 3D Animation of Rem 700 Action — Watch Video
The Model 700 series of bolt-action rifles have been manufactured by Remington Arms since 1962. All are based on basically the same centerfire bolt action. They are typically sold with an internal magazine depending on caliber, some of which have a floor-plate for quick-unloading, and some of which are “blind” (no floor-plate). The rifle can also be ordered with a detachable box magazine. The Model 700 is a development of the Remington 721 and 722 series of rifles, which were introduced in 1948.
The Rem 700 is a manually-operated bolt action with forward, dual opposed lugs. It features “Cock On Opening”, meaning the upward rotation of the bolt when the rifle is opened cocks the firing pin. A cam mechanism pushes the firing pin’s cocking piece backward. The bolt face is recessed, fully enclosing the base of the cartridge. The extractor is a C-clip sitting within the bolt face. The ejector is a plunger on the bolt face actuated by a coil spring. The bolt is of 3-piece construction, brazed together (head, body. and bolt handle). The receiver is milled from round cross-section steel.
This video was made with the help of the World of Guns: Gun Disassembly interactive encyclopedia with 3D rendering. This remarkable web-based software allows users to view the inner workings of hundreds of different rifles and pistols — everything from a .22 LR Ruger to a .55-caliber Boys Anti-Tank rifle. There are also 25,000+ parts diagrams. This is a remarkable technical resource. SEE MORE HERE.
Cutaway 3D Animation of AR15/M16 Action — Watch Video
The AR platform rifles are a semi-automatic version of the M16. These feature distinctive upper and lower receivers which can be readily separated via front and rear pins. The upper includes the barrel, handguard, forward gas tube, and bolt assembly, while the lower contains grip, trigger group, fire selector, and mag well. In addition the lower is attached to the stock which encloses the buffer assembly.
The original ArmaLite AR-15 was a select-fire, air-cooled, gas-operated, magazine-fed rifle designed by American gun manufacturer ArmaLite in 1956. It was based on Armalite’s AR-10 rifle chambered for the 7.62×51 NATO (.308 Win). In 1959, ArmaLite sold its rights to the AR-10 and AR-15 to Colt. Some key modifications were made — most notably, the charging handle was re-located from under the carrying handle to the rear of the receiver. The redesigned rifle was adopted by the U.S. military as the M16 carbine, which went into production in March 1964.
These videos found by Boyd Allen. We welcome reader submissions.
Set aside some TV time tonight folks. There is a great episode of Shooting USA on the Outdoor Channel. Over the course of tonight’s hour-long broadcast there are FOUR notable features well worth watching. Show times are 8:00 pm Eastern and Pacific; 9:00 pm Central.
1. AR-Platform 6.5 Creedmoor Precision Rifle. In this segment John Scoutten works with JP Enterprises on a 6.5 Creedmoor semi-auto precision rig using JP’s LRP-07 components. This sequence showcases the AR10-type platform’s abilities with mid-sized cartridges.
2. Fort Benning Multi-Gun Challenge. This is one of the best 3-Gun events of the year. If you like fast action, with rifles, pistols, and shotguns, you’ll love this Shooting USA sequence. The U.S. Army Marksmanship Unit at Fort Benning, Georgia hosts one of the toughest and most challenging multi-gun matches. Watch top competitors move through difficult stages that test strength and agility as well as marksmanship.
Multi-gun competition tests shooters’ skills with rifle, pistol, and shotgun, running stages “on the clock”. You must be fast AND accurate to successfully complete a course of fire.
3. Classic Arms — The U.S. Army’s Model of 1917 Rifle. The Model 1903 Springfield is perhaps more famous, but more Model 1917 rifles were actually issued to American troops in World War I. This sequence covers the history of this important American battle rifle.
4. Rimfire Challenge World Championship (RCWC). This is a great family event. The Rimfire Challenge is a timed, short-range event for .22 LR handguns and rifles. In recent years, the RCWC has been held in Alabama with 16 stages, 8 for rifle and 8 for pistol. This major match attracts hundreds of competitors from around the nation. It’s fast and fun with instant feedback from ringing steel plates. The RCWC is family-friendly event that’s great for all skill/experience levels.
Savage’s MSR 10 Long Range is now available in 6mm Creedmoor. We think this rifle is a good choice for PRS Gas Gun matches in the Open Division. This AR10-type rig can shoot a larger, more capable cartridge than a .223 Rem (or 224 Valkyrie). And we think the 6mm Creedmoor is definitely a good choice for tactical/practical applications. In fact in the first-ever PRS gas gun match, the winner ran a 6mm Creedmoor. (Story HERE).
The 6mm Creedmoor case design allows room for long, heavy bullets while still functioning in an AR10-size action. The 6mm Creedmoor has become popular with High Power and PRS shooters because it offers excellent accuracy, good ballistics, and moderate recoil. As explained below, the 6mm Creedmoor offers a flatter trajectory, with less recoil, compared to the “parent” 6.5 Creedmoor.
Savage’s semi-automatic MSR 10 Long Range boasts some nice features — such as a Magpul PRS Gen 3 stock, and non-reciprocating, side-charging handle. The MSR 10 Long Range also features a two-stage target trigger, plus upgraded barrel with 5R rifling and Melonite QPQ finish. MSRP is $2284.00.
Savage MSR 10 Long Range Features:
– Non-reciprocating side charging handle
– Fluted 22.5″ heavy barrel with Melonite QPQ finish, 1:7.5″-twist rate
– Custom forged upper/lower for unique look and compact size
– Magpul PRS Gen3 buttstock
– Free-float M-LOK rail
– Two-stage target trigger with nickel boron treatment; 2.5 to 4-pounds
– Chamberings: 6mm Creedmoor, 6.5 Creedmoor, .308 Winchester
Savage MSR 10 Long Range (6mm Creedmoor, 6.5 Creedmoor, .308 Win)
Ballistic Comparison: 6mm Creedmoor vs. 6.5 Creedmoor
Which has better ballistics, the 6mm Creedmoor or the original 6.5 Creedmoor? Well, the answer depends on your bullet choice and the speed of your load. We went to the Hodgdon Reloading Page and selected the MAX listed loads for H4350 for each cartridge, choosing Sierra’s 107gr MatchKing for the 6mm Creedmoor, and Sierra’s 142gr MatchKing for the 6.5 Creedmoor. Hodgdon’s max H4350 load for the 6mm Creedmoor with 107gr bullet yields 3009 fps at 60,300 psi (24″ barrel). The max H4350 load for the 6.5 Creedmoor with 142gr bullet runs 2694 fps at 59,800 psi (24″ barrel).
With these listed Hodgdon Max loads, the 6mm Creedmoor had a flatter trajectory and less wind drift. Here is a quick comparison, based on data from JBM Ballistics.
6mm Creedmoor with 107gr SMK Hodgdon H4350 Max “Book” Load, 3009 fps
Commentary — Ballistics Comparisons and “Beyond Book” Loads
We are aware that some shooters are running faster loads in both 6mm Creedmoor and 6.5 Creedmoor rifles. The ballistics comparison would also change with different bullet choices for one or both calibers. However, by using Hodgdon’s listed max loads with the SAME Powder this is a meaningful starting comparison for the two related chamberings. Bottom line, the 6mm Creedmoor shoots flatter and has less wind drift. It also definitely has less recoil. This 6mm Creedmoor load has 2150.8 ft/lbs of energy at the muzzle. The listed 6.5 Creedmoor load has 2288.0 ft/lbs of energy at the muzzle.
Of course we know some guys are running their 6.5 Creedmoor faster with 140gr-class bullets. That would alter the comparison. But if you ask most actual PRS competitors who have campaigned BOTH the 6mm Creedmoor and the 6.5 Creedmoor, they will tell you the 6mm Creedmoor has less recoil, and a somewhat flatter trajectory. That makes this new 6mm Creedmoor Savage MSR 10 rifle an interesting alternative to its 6.5 Creedmoor brother.
Looking for your first black rifle, i.e. an AR-platform semi-auto? Now is a great time to buy. Gunmakers stepped up AR production dramatically in 2015-2016, to satisfy high demand by citizens who feared that a Democratic Presidential victory would result in bans on semi-auto rifles. Well Hillary Clinton lost, so the panic buying ended. That means there is an over-supply of ARs at this time. So AR manufacturers are cutting prices and offering significant money-back rebates.
Perhaps the most attractive AR offers right now are the Bushmaster and DPMS Mid-Year Rebates. You can save $125.00 on the most popular Bushmaster and DPMS models. Bushmaster QRC rifles are $75 off, while the DPMS Oracle models (both .223 and .308) are $50 off.
You will want to act soon to qualify for these Mid-Year promotions. You have two more weeks to buy — Both Bushmaster and DPMS Rebate programs end July 31, 2018.
DPMS/Panther Arms makes a wide variety of rifles, including AR10-type rifles that handle the .308-Win family of cartridges. DPMS’s GII Series is an AR10 evolution with lighter weight and more AR15 parts interchangeability. DPMS claims the GII is “the lightest, most reliable, technically advanced .308 MSR”.
Miles of Aisles and thousands of new products. SHOT Show, held each January in Las Vegas, is a near-overwhelming circus. There is so much to see, with new products from countless manufacturers, large and small. Here is the last official Highlights video from SHOT Show 2018. This 19-minute video provides a comprehensive summary of all there was to see and do at SHOT Show.
Weatherby Moves to Wyoming — Interview with Adam Weatherby
One of the biggest industry new items was Weatherby’s exodus from California. We reported this move in detail, explaining the TOP FIVE REASONS gun companies leave California. In this video, Weatherby President Adam Weatherby explains his company’s goals in relocating to Sheridan, Wyoming. Unlike California, Wyoming is a Second Amendment-friendly state. Plus Wyoming also has no state tax on corporate earnings (California is 8.84%):
Featured New Products — Video Previews
The Firearm Blog (TFB) had a large presence at SHOT Show, with multiple video teams covering Range Day and then the main event at the Sands Expo Center. Here are some TFB product highlight videos, showcasing interesting new products released at SHOT Show 2018 and/or Industry Day at the Range:
Lithgow LA105 Tactical Rifle from Australia
Australia’s Lithgow Arms has a new rifle for the PRS game. Called the LA-105 Woomera (named for an Aboriginal spear-throwing device), this is basically a Lithgow Arms LA102 barreled action in a Kinetic Research Group (KRG) chassis similar to the Whiskey-3 and X-Ray chassis systems. Initially, the LA105 Woomera will be released in two calibers, 6.5mm Creedmoor (1:8″ twist) and .308 Win (1:10″ twist). The barrel twist rates should stabilize High-BC match bullets. Thanks to the KRG chassis, the LA105 Woomera takes the popular AICS magazines, rather than the Tikka T3 magazines of its predecessor.
Click to View Full-Page Specifications (easier to read):
Sako Carbon Fiber Stocks and New TRG 42 and 22
Sako has new, ultra-light carbon fiber stocks for the Sako 85 hunting rifle series. There are two carbon offerings, the CarbonLight and Carbon Wolf. The latter has cool push-button adjustments for comb height and length of pull. The Sako 85 Carbon Wolf features a nice ergonomic grip that’s very comfortable in the hand. We thought this was one of the nicest new stocks at the Show. At Industry Day at the Range, Sako also showcased new “AI” versions of the TRG 42 and 22 models. Both versions feature improved folding buttstocks, with adjustable cheekpiece and LOP. TRG tested the .338 Lapua TRG 42 on Industry Day at the Range.
Brownells Retro AR15 and AR10 Rifles
After testing Brownells’ Retro AR-15s at Industry Day at the Range, TFB’s Corey Wardrop checks out the new AR-10A and AR-10B at Brownell’s SHOT Show booth. Brownell’s 7.62x51mm AR10 is faithful to the original, with important upgrades. The BRN10B (“late style”) is also shown. For the keen-eyed, Gene Stoner makes an appearance in the background. CLICK HERE to view Brownell’s entire Retro AR line-up, both AR15 and AR10.
Does your Black Rifle have a sloppy upper/lower fit? That can be annoying; what’s more, loose fit can limit accuracy potential. Here’s a clever solution for poor-fitting AR-15 and AR-10 upper and lower receivers. The new JP MicroFit takedown pins can improve even the sloppiest ARs, providing a rock-solid upper/lower receiver fit.
MicroFit pins come in three sizes and two types: standard (“mean”), oversized, and undersized, with types for both front and rear of the receivers. The mean pins match standard takedown pin sizes while the over- and under-sized vary by slightly more than .001″ (+/-) from the standard diameter. NOTE: Although most poor-fitting receivers are loose, some are too tight. Very tight receivers, such as post-Cerakote, can be remedied with the undersized pins.
Shown is JP Enterprises’ PSC-12™ upper assembly with LRP-07™ lower assembly.
“An AR with a loose upper/lower receiver… will not reach its accuracy potential. That was the goal with our original JP Tension Pin, but MicroFit™ pins provide the same result without tool-assisted takedown. The MicroFit pins require no modification to the receiver. They simply replace your current pins”, stated JP Enterprises founder John Paul.
JP’s MicroFit pins feature a polished black finish with a hard, durable QPQ coating. This provides smooth insertion/removal plus excellent corrosion resistance. All pins feature a two-faceted punch or bullet capturing recess. This allows the user to apply force to the pins safely without risking scratching the receiver. JP’s MicroFit pins are sold as both as individual pins and as replacement sets.
Today, AR-platform rifles are hugely popular. Dozens of manufacturers sell AR-type rifles, in a wide variety of configurations and calibers. But before there were M16s and AR-15s, ArmaLite produced a 7.62×51 caliber rifle, the AR-10. Yes before there were millions of 5.56 black rifles, there was a .30-caliber big brother with reddish-brown furniture. Invented by Eugene (‘Gene’) Stoner for the Armalite company in the late 1950s, this is the father of all of today’s AR-platform rifles. Way ahead of its time, this remarkable, select-fire battle rifle weighed just 7.25 pounds as first developed.
If you’re curious about the AR-10, in this video, Jerry Miculek puts an original 1957-vintage AR-10 through its paces on the range. This extremely rare, early-production rifle was provided by Mr. Reed Knight and the Institute of Military Technology. (The gun in the video was actually produced in the Netherlands under license, see video at 4:40.) This AR-10 is the direct ancestor of the AR-15, M16, and many of the modern sporting rifles that we use today.
The AR-10 was slim and light, weighing in at around 7 pounds. Some folks might argue that the original “old-school” AR10 is actually better that some of today’s heavy, gadget-laden ARs. The AR-10’s charging “lever” was under the carry handle — that made it easier to manipulate with the gun raised in a firing position.
You’ll notice there is no “forward assist”. Inventor Gene Stoner did not believe a separate “bolt-pusher” was necessary. The forward assist was added to solve problems encountered in Viet Nam. Some critics say the forward assist “only takes a small problem and makes it a big problem.” For today’s competition ARs (that are never dragged through the mud) the forward assist probably is superfluous. It is rarely if ever needed.
Note also that the handguards are fairly slim and tapered. Today, six decades after the first AR-10 prototypes, we are now seeing these kind of slim handguards (made from aluminum or lightweight composites) used on “full race” ARs campaigned in 3-gun competition.
History of the AR-10
The AR-10 is a 7.62 mm battle rifle developed by Eugene Stoner in the late 1950s at ArmaLite, then a division of the Fairchild Aircraft Corporation. When first introduced in 1956, the AR-10 used an innovative straight-line barrel/stock design with phenolic composite and forged alloy parts resulting in a small arm significantly easier to control in automatic fire and over one pound lighter than other infantry rifles of the day. Over its production life, the original AR-10 was built in relatively small numbers, with fewer than 9,900 rifles assembled.
In 1957, the basic AR-10 design was substantially modified by ArmaLite to accommodate the .223 Remington cartridge, and given the designation AR-15. ArmaLite licensed the AR-10 and AR-15 designs to Colt Firearms. The AR-15 eventually became the M16 rifle.
AR-10 photos from Arms Izarra, a Spanish company specializing in de-militarized, collectible firearms. Interestingly, this particular AR-10 was produced in the Netherlands under license.
Trigger images from 
This video was made with the help of the 
