3/9/10 - It's been about seven years since the Vltor Weapons Systems Carbine Modstock was introduced. The new IMOD Stock (Improved Modstock) is the replacement for the Carbine Modstock, and is a blend of features taken from the EMOD (Enhanced Modular Stock) with the original Modstock. It is available in the familiar Standard and Clubfoot configurations and kits that the original Modstock was offered in.

Standard and Clubfoot IMOD stocks

Basic combo kit

Basic kit

Overall design - The IMOD offers the same modular features as the original Modstock; interchangeable storage tubes and cheek pieces, with the addition of features found on the EMOD stock. It has also been beefed up to be stronger than the original. When the Modstock came out, a slip-on rubber buttpad was offered for it. I'll have to admit that I wasn't a huge fan of it, as the toe turned rearward instead of forward, and wasn't as comfortable for rolling up into the shoulder. It was also wider than the rear of the stock, since it slipped over it, and wasn't securely fastened to the stock. When the EMOD came out with its modular buttpad/strike plate, I often wished that a similar pad would be available for the Modstock (and now that wish has been granted). The EMOD buttpad is rubber molded over an aluminum strike plate, with an angled-forward toe.

Modstock (top) and standard IMOD

Slip-on vs. IMOD buttpad

Textured paddle

Removable buttpad

The IMOD buttpad is rubber molded to a plastic plate, for weight savings. The toe of the IMOD has been lengthened very slightly from the original Modstock and is angled forward with a negative camber, like the EMOD. It has the same grippy tread pattern molded into the pad as the EMOD. The buttpad can be removed if desired, and the rear of the IMOD stock has the same molded checkering as the original Modstock. I suspect that most owners will leave the buttpad on, as it greatly improves purchase, comfort, and doesn't add much length (it's about 3/8" thick).

The length of the IMOD is exactly the same as the Modstock, and the side storage tubes are the same as well. The EMOD has two sling slots - one on top of the rear and the other one below the storage compartments. The lower one is now angled to allow easier routing of a sling when the compartments are installed. On the clubfoot version, the third sling slot below the QD sling cup has been eliminated on the IMOD.

The IMOD has a QD sling swivel cup in the same location as on the Modstock. The stock release paddles have been redesigned on both the standard and clubfoot versions, with texture added to the actuation surfaces for improved grip. The IMOD is available to fit both milspec and commercial buffer tubes in Black, FDE (Flat Dark Earth), and Foliage Green.

Clubfoot Modstock and Clubfoot IMOD

Textured paddle

EMOD (L) and IMOD (R)

EMOD and IMOD

FDE and Foliage IMODs

Compared to the EMOD, the IMOD is shorter and not as tall. As I have mentioned before, I like the EMOD for SPR or 'Recce' type scoped rifles, and the Modstock (and now IMOD) for use with body armour. The EMOD is too long for me when wearing plates, so I'm glad to see the IMOD come out, as I do like the angled toe and buttpad of the EMOD. Those of you who like your original Modstocks will really like the IMOD.

Clubfoot IMOD

FDE standard IMOD

Standard IMOD

6/13/10 - The Vltor Weapons Systems A5 Buffer & Recoil System was developed for the specific needs of U.S. Military users of the M16A4 rifle (or AR-15's with rifle-length gas systems). The A5 system provides the functionality of a collapsible stock while maintaining rifle-length buffer system reliability. It includes a newly designed buffer and receiver extension.

Description - One of the issues encountered by current users of the M16A4 rifle (the USMC and U.S. Army) is its overall length and maneuverability. The 20" barrel (while providing additional velocity) and fixed A2 stock configuration has proven less than optimal for some of the close-quarter/house-to-house fighting encountered in recent engagements, especially when combined with the body armour being worn. The added thickness of body armour, sometimes consisting of soft inserts plus a plate can cause the A2 stock to be too long, especially when a less bladed stance is used.

Another issue is that of reliability. As the M16 series of rifles evolved into specialized configurations like the SPR, Mk18 etc, each of them using different combinations of barrel and gas-systems, attempts to universally use the standard collapsible stock on all platforms have encountered issues. The solution is not as simple as sticking the A4 rifle uppers on lower receivers with carbine collapsible stocks. Some of the issues that arise are increased rate of fire on full auto and inconsistent carrier velocities. Putting a heavier weight buffer in a carbine system (like the Army's H6 buffer) is one solution, but also comes with its share of associated issues.

The Vltor A5 package is a replacement stock system for users of the the M16A4 rifle (as found on the M16A4) who want to maintain the same reliability, carrier velocity and rate of fire as the rifle-length A2 stock, while adding the functionality of an adjustable stock. This is achieved by a new buffer and receiver extension (buffer tube), and the use of the standard rifle length buffer spring.

The A5 system can be used on all direct impingement systems of any gas system length, and also reduces cyclic rate on short-barreled rifles and maintains a much more consistent bolt velocity and rate of fire on all current issue weapons based on the M16. With different A5 buffer weights available, the A5 system can also be used with piston systems, or over-pressured rifles.

The Vltor A5 Kit consists of an A5 Standard Buffer, rifle-length spring, A5 receiver extension, EMOD stock, receiver end plate and castle nut. Other A5 buffer weight configurations will be available individually/separately.

Buffer - With an AR or M16 rifle stock system, part of the rifle buffer is just 'spacer'. It's there to allow the longer rifle-length buffer tube to be used without affecting the length of travel of the bolt carrier (which is the same whether a rifle or carbine buffer system is used). Vltor saw that this extra spacer length could be eliminated while still using a standard rifle length spring, and came up with the A5 buffer. The A5 buffer is approximately the same length as a rifle buffer with the 'spacer' portion at the front removed. It is 4", versus the 3.25" of a carbine buffer. The A5 can be had in different weights, but the standard A5 weight (shown here) is about 5.3 oz (2 steel, 2 tungsten weights), and matches the same carrier velocity as the A4 configuration. Instead of a carbine spring, the standard rifle-length buffer spring is used. The A5 H1 buffer has 3 tungsten, 1 steel and the A5 H2 buffer has 4 tungsten weights.

The use of a rifle spring provides consistency that the carbine-length spring does not. It was found that the more coils that a spring has, the more consistent the spring rate upon each compression.

A5 Buffer kit

A5 vs. carbine buffer

A5 buffer

Rifle buffer (top), A5 buffer (bottom)

Receiver Extension - Just as the A5 buffer is 3/4" longer than the carbine buffer, the Vltor A5 receiver extension is 3/4" longer, making it 8" long, vs. 7.25" for a carbine tube. The A5 receiver extension has 7 positions and was designed to be used with Vltor's EMOD stock. Any mil-spec carbine stock can be used with the A5 receiver, but the additional length means that standard carbine stocks won't close all the way, as illustrated in the photo with the IMOD below on the right. For me, it's a non-issue as I usually shoot with the stock in that position or another notch out.

A5 receiver extension (above) vs. carbine

A5 with EMOD

A5 with IMOD

Shooting with the A5 system is almost identical to shooting a standard rifle-length stock/recoil system, except that you have a collapsible stock. I tried out the A5 with a few different uppers, and felt recoil is a bit softer than with a carbine system. I have a few hundred rounds using the A5 so far (with no issues), and one carbine system upper I had which was a bit finicky with a regular buffer worked 100% with the A5 kit. I'm just a very limited statistical sample of one, but A5 kit-configured weapons have gone through extensive testing (over 70,000 rounds) so far with very promising results. It has also been tested on the HK 416 with 10.5" and 14.5" barrels and shown that the cyclic rate is decreased for both barrel lengths substantially in unsuppressed and suppresed configurations.

1/10/10 - Magpul Industries' new AFG (Angled Fore Grip) is a rail-mounted forward grip/index point designed to improve weapon ergonomics and increase shooter speed and efficiency. Rather than a vertical grip, the AFG features an angled gripping surface with interchangeable insert, that provides a more ergonomic interface when used with a particular grip/shooting style. The AFG is available from Magpul Dealers.

Background - There are numerous grip devices available on the market that attach to the bottom of a railed handguard; all designed to aid in the comfort and control of the weapon while firing or holding it. They range from AR15-style pistol grips (similar to the old Thompson SMG front grip) to round handles and handstops. The most common is the vertical fore grip, which comes in various lengths. When vertical grips were first introduced, the most common method used to grip it was with the hand wrapped completely around the grip like a fist. The thumb was used to activate flash light switches on the opposite side of the support hand. Some of the disadvantages to this grip is that the wrist is at an angle to the fore arm and the hand is supporting the weapon from below rather than alongside, allowing the weapon to wobble from side to side.

Influenced by 3-gun competition shooting, where competitors often used longer tubular handguards with the support arm extended and the thumb over the top and index finger pointed forward, many started using a similar thumb-forward grip (or 'thumb break grip') with the vertical grip. This grasp improved control of the barrel especially when moving it from one target to another. As more shooters started using this grip, they found that more than half of the vertical grip was not being used, so manufactuers responded with shortened, or 'stubby' vertical grips. The only drawback to this set up is that the hand is at an angle, while the vertical grip is not, so the hand 'fills' the corner between the grip and the bottom of the rail.

Handstops are not vertical grips, but provide an index and additional purchase when using a standard bottom support grip or 'side wrap'. I haven't found them to be very ergonomic as the top fore arm muscles tend to be over-extended.

The Magpul AFG puts the hand in a position very similar to that of the thumb break grip, but creates an improved interface for it by means of the angled surface which matches the angle of the hand.

Overall design - The AFG is made of polymer, measures about 5.5" long and has an inverted triangle instead of a vertical grip. It installs onto a rail by sliding it from the front, and it is secured by a single flat-head screw. The front portion of the AFG has a widened textured area and front hand stop. The front angled surface of the AFG is also textured with anti-slip grooves. There are two interchangeable inserts; one with an 'A2' style finger bump and the other is flat. The A2 insert can be installed two ways - with the bump higher or lower, according to user preference. To change out the inserts, the AFG is disassembled into its two halves by loosening two allen head screws and the insert swaped out or rotated. The apex of the triangle has a forward facing bump which serves as a bottom hand stop.

AFG with finger bump installed

Top view

Bottom view

Disassembled

Flat insert installed

Observations/Notes - The AFG takes up quite a bit of rail space, and after trying it on a few different length handguards/rails, I came to the conclusion that it works best on longer rails (at least 9"). One of the reasons is that the AFG has a fixed angle which is optimal for hand placement within a certain range of distances. Used within that range, the angle of the AFG ensures comfort of the hand/wrist, as well as a secure purchase around the handguard. When the AFG is moved too far back, the angle of the wrist falls outside that 'comfort' range, and a more vertical angle becomes more comfortable (for me). That's when I'd prefer a vertical stubby for the thumb break grip. This is just personal preference.

I installed it on a LaRue 7.0 rail with carbine gas system, and as you can see from the photos below on the right, the AFG takes up most of the bottom rail space. When installed on the rail with the front of the AFG behind the gas block, the wrist can end up at a less-than-optimal angle. Moving it forward until the hand stop is flush with the front of the gas block improves the wrist angle some, but puts the thumb right where the front sight base is. If there's a fixed front sight base, that's right where the thumb wants to be, and wrapping your hand around a hot gas block or placing your thumb right alongside it isn't very desirable. Another reason against mounting one on a carbine length handguard is that there's no room for a light. On some handguards, the forward part of the AFG prevents the use of rail covers or rail-mounted accessories. You can see that the front portion is right up agains the side LaRue rail, and that a rail cover will only fit behind it. For rail covers to be used, the AFG requires a taller bottom rail like the Daniel Defense Lite or KAC rails, or enough width. The DD Omega is slimmer than the Lite and may not have enough width to install panels with the AFG.

I installed it on a rifle length KAC URX II, which is a 12" rail. For me, this is the optimal length, as it places the AFG forward enough for comfortable extension of the arm and angle of the wrist. It also leave enough room in front to mount a light. Illustrated below are an X300 and light in Vltor SMQ-OCG offset mount. Both lights are easily activated by the support thumb.

On rifle length URX

X300 on side rail

Bottom view

Vltor SMQ-OCG

On 7.0 rail

Installed towards the front

I've illustrated the AFG below on the rifle using a 'thumb on top' and 'thumb forward' grip. I have small hands, so my thumb is usually forward or a little over the top. Used this way, I feel that the AFG is at the ideal position and angle. The third picture on the right shows a TD stubby grip used on a shorter rail. This is the 'thumb break' grip that I normally use, and it's very similar to the position that the AFG puts my hand in. For shorter rails which require me to place the grip further back, I still prefer a vertical stubby because I can vary my grip a little easier depending on how much of my hand is on the grip vs. the handguard. Also, with shorter rails, a vertical grip doesn't interfere with rail-mounted accessories or rail panels.

Thumb on top

Thumb forward, X300 access

Thumb break grip with stubby

I normally dislike the finger bump on the A2 pistol grip because it's always located under a finger, but with the AFG, I like the finger bump, as I felt that it gives me additional purchase on the grip without having to grip too tightly. With the finger bump in the lower position, it fits between my middle and ring fingers perfectly. One thing I'd like to see with the AFG is a variant with a slimmer front portion so that it doesn't interfere with rail mounted accessories or rail covers on shorter rails. The other is to make the front texture a bit more aggressive.

Magpul emphasizes that the AFG falls into the category of 'theory based' products, which means that the AFG is not just meant to simply replace a vertical grip or handstop on every weapon, but that its usage requires the proper education, understanding and training of the techniques that the AFG is designed for. Without that, the user may not be using the AFG in the manner it was designed for, and it won't be a right fit for him.

Im summary, based on my limited experience, I found the AFG to be very comfortable and conducive to a thumb-forward or 'over the top' grip, working better with longer rails than shorter ones. Mostly due to the interference with rail mounted accessories and covers on some rails, I feel that the AFG is best used with rails 9" and longer.

Gear Sector Rail Mount Hand Stop

6/10/10 - The Rail Mount Hand Stop from Gear Sector is used for improving weapon purchase and control by providing a 'stops' for the hand on the handguard, which aid in pulling the rifle into the shoulder or driving the gun, depending on how they're mounted. They provide a consistent index on the handguard when using rail mounted accessories, like flashlights.

FDE and black hand stops

Description - As people's tastes and shooting style change over time (sometimes coming full circle), so do the accessories. Hand Stops have been around for a while in target shooting circles. Normally used with a target sling, a handstop mounted at the bottom of the stock fore end provides an index position and prevents the support hand from slipping forward on the fore end. A hand stop on a tactical carbines can be used to prevent the hand from slipping forward on a short barreled rifle, or as a mini vertical grip to help pull the rifle into the shoulder. We've seen vertical grips shrink in length; with most companies now offering regular and stubby lengths to accommodate different shooting styles (thumb under, forward, or on top etc). Some folks have cut their vertical grip down even more, ending up with little more than a nub. For those who dislike vertical grips, and prefer just to wrap the support hand around the handguard/rail, the hand stop doesn't change the grip significantly, but is used as a brace to extert pressure forward or rearward, depending on how it's placed.

The Gear Sector Rail Mount Hand Stop was designed as a low profile, ergonomic solution for increased weapon control. The Hand Stop is about 0.87" tall, and has a flat surface and a contoured surface that indexes into the web of the hand. It can be used singly or on pairs, and placed anywhere on the rail where the user sees fit. The Hand Stop has the same ergonomic platform as their sling mounts, which consists of a base which looks like the cross section of a rail panel that slides onto the rail and is held securely by a screw/clamp assembly. The mounts are CNC machined from 6061-T6 aluminum and finished with a mil-spec type III, class II hard anodize. They are then Cerakoted in black, foliage green, OD green, or FDE (flat dark earth). Each Hand Stop weighs about 0.6 oz.

FDE handstop pair

Side-mounted handstop

The Hand Stop has a screw and clamp assembly, which are removed for installation. Each Hand Stop comes with an allen wrench and small packet of Vibra-tite VC3 thread locker, which is applied to the screw threads and allowed to dry. The Stop is then slid onto the rail, the screw/clamp assembly is inserted and tightened down. The screw prevents the mount from sliding along the rail.

The Hand Stop is illustrated above mounted in pairs and singly (as a side mount). Used in pairs, the Hand Stops limit both rearward and forward movement of the support hand, and provide a means of pulling the rifle into the shoulder without exterting as much pressure around the handguard with the support grip. The forward Hand Stop isn't necessary for exerting a rearward force, but is useful to prevent the hand from straying too far forward onto a hot barrel/gas block or muzzle on an SBR. After playing with them for a while, I prefer placing them closer together (the black gun) rather than further apart like on the tan one. A side mounted hand stop can provide a consistent index/position for the hand. Also, when shooting from the sides of barricades, some teach to hold the rifle rail against the side of the barricade to steady it, with some forward pressure. Instead of resting the barrel against the barricade and pressing against the front of the rail, a side or bottom mounted handstop can be pushed against the barricade, keeping the barrel from touching the wall.

I've used the KAC hand stop, and as a lefty, did not like the sharp edge where the mounting screw clamp was located. The Gear Sector Hand Stop is more comfortable to me, and while lower profile, I have not had my hand slip past it. Having my support hand sandwiched between the front and rear Hand Stops gave me a more positive grip on the handguard. Well, actually, I was able to obtain a good grip on it without squeezing it as much. Note that hand stops are not for everyone. If you're used to a vertical grip, and prefer that to no grip at all, the hand stop might not be your cup of tea. But if you're looking for some kind of index feature or a very low profile stubby, the Gear Sector Hand Stop would be worth considering.