I like GGG stuff alot....but id spend the $60 extra for a bobro every time. if you don't have the extra $60, don't eat lunch for the next 2 Weeks and buy it then. (that's how I make most of my upgrades, sometimes extending to skipped breakfasts as well :P )
The Sierra 7 Bipod w/ Rubber Feet gives the shooter the control and stability to make the perfect shot, even under the most difficult circumstances. This bipod manufactured by the experts at Sierra 7 are machined to allow for the maximum amount of strength and precision, and features rubber feet that are rugged, tested, and reliable. The Sierra 7 Bipod w/ Rubber Feet, Pan & Tilt includes the pan feature to be precise and the smoothness of the tracking ability cannot be overstated. The Sierra 7 Bipod w/ Rubber Feet also comes with tilt to rotate smoothly regardless of how much tension is applied to the mechanism. With the Sierra 7 Bipod w/ Rubber Feet & Pan, you can bet on precision control without slipping and sliding all over the place.
The SR-5 is convenient, stable, heavy, easily manipulated, and tremendously effective. It was fun to shoot in multiple configurations, and I found that from a sitting position, I really enjoyed shooting with the legs at 45 degrees inwards. My groups improved markedly at 100 yards between my old Caldwell and the SR-5. This bipod is about as solid as any billet accessory or lower that I can think of. The only issue I experienced was the feet unscrewing themselves between the first few shots and when I took my rifle out for cleaning after the range. This is easily rectified with some Loctite. The spring-loaded legs are fun to toy around with, and very convenient. Being able to adjust on the fly while shooting without needing to get both hands on the bipod and unscrew or otherwise mess with the legs to change their length is a great feature.
6/12/09 - The ARC (Advanced Reliability Combat) Magazine from TangoDown is now offered in 20-round capacity. Why 20 rounds? Some folk prefer to use the 20 round magazine for its lower profile, so they can get closer to the ground when using a bipod, instead of being limited by the 30-round magazine sticking out the bottom.
Attachment - The BOBRO bipod attaches via their MCU (Master Coupling Unit), which is the system that permits attachment of the bipod to any 1913 rail. The bipod is slid onto a rail (you must slide it from the front of the rail), not rocked on from the side. There is a block, or central 'driver' with an index bar that rises when the thumb knob at the bottom of the MCU is turned. The index bar is set within an available cross-slot on the 1913 rail and the knob tightened clockwise until the unit is securely locked on.
Cant - The bipod 'body' (the part to which the legs are attached) pivots around a pin attached to the MCU. This allows the bipod to cant. There is enough resistance in the pivot to support the weight of the weapon and keep in at the cant angle chosen. It will not flop over to one side or the other. It's not too tight, however, and the cant of the rifle can be adjusted easily. The tension is set at the factory and really needs no adjustment. There is no built-in traverse.
Deployment Mechanism - The BOBRO bipod uses what they call CTM (Collapsing Triangle Mechanism) technology to permit deployment of the legs without having to push any buttons or controls. The legs are held in the stowed (up) position by spring tension. A spring on each side puts tension on the end of a pivoting arm (or 'clawbox'). A post that's attached to the side of the upper leg runs in a channel along the inside of this clawbox. The post engages a spring-loaded claw that locks the post at the end of its travel when the leg is fully deployed. The clawbox pivots as the leg pivots down, with the tension spring on the side resisting the downward movement of the leg until the post passes a 'neutral point' and the tension spring starts pulling it into its locked position. A conical interface between the post and the claw applies constant and even pressure to ensure that the bipod remains positively locked and cannot collapse (like the Harris) without the user unlocking the claw. When deployed and locked out, the clawbox forms a 'triangle' providing a strong support strut for the leg against both forward and aft pressure. Pressing the forward part of the claw disengages it from the post, and allows the legs to be pivoted forward and stowed. This can be done with the same hand, one leg at a time. The clawbox pivots up and the triangle disappears when the legs are returned to the stowed position, hence the 'collapsing triangle mechanism'.
Legs and Height Adjustment - The upper legs are actually outer sleeves in which the lower legs slide in and out. The bipod will adjust the height of the bottom of the rail that its attached to from 7" to 9.5". Height adjustment is accomplished by loosening the thumb knob on each leg and sliding the inner leg up or down, then tightening the knob. There are no notches or spring assists. Personally, I'd prefer pre-set notches every 0.5" or so (one feature of the Harris bipod with notches I do like), and a push button release (which is also faster than loosening or tightening a knob), so that there is no chance of the knob loosening and the leg collapsing. If you're doing any kind of quick transitioning from standing/kneeling to prone, where the rifle and bipod might hit the deck with the rifle's weight behind it, you do have to ensure that the knobs are tightened properly. This is just my personal preference/opinion; others might prefer loosening and tightening a knob.
12/26/06 - Vltor's bipod (or bipod legs) take a different approach to the rail mounted bipod. Instead of a one-piece assembly that attaches to the bottom of a rail, the Vltor bipod legs mount to the host weapon separately on the side rails. Instead of folding beneath the handguard, the Vltor bipod legs stow above the centerline of the bore, reminiscent of the Sako TRG 22/42. This puts the center of gravity of the weapon lower, resulting in a naturally more stable position.
The Vltor bipod utilizes the carbon fiber-reinforced TangoDown legs from the ACB-4 bipod featured below, and will be available in tan or black. Instead of a common center mount to which the legs are attached, each leg has its own rail clamp. Some of you might recognize it as the same thumbscrew mechanism as seen on Vltor's Tactical Light Scout Mount. Each leg is simply attached anywhere on the side rails. The legs can be mounted to stow facing backwards or forwards. When mounted facing back, they're located further forward on the rail, and vice versa. Since there is no built-in traverse feature, mounting them further back on the rail, facing forward, makes it easier to traverse from side-to-side, as the pivot point is closer to the shooter. However, for an SPR or target type rifle, mounting them forward like a conventional bipod works as well. There is no cant feature built in, either, except for the 3 height adjustments in the legs for uneven ground.
Although the feet have a 'front' and 'back', the legs can be mounted on either the left or right side interchangeably. This doesn't affect the function, but it enables a slightly difference in height, and the legs will appear to be 'backward' (look at the M4 VIS/M203 photo - the legs are mounted 'backward'). If you look at the center photo immediately below, you can see that the forward and rear-facing mounting options put the stowed legs at different heights relative to the rail. The leg facing forward stows alongside the side rail, whereas the leg facing to the rear is above the side rail. The right and left bipod legs can be swapped, and either mounting height can be chosen. Note tha the bipod feet might have to be pulled outwards a bit for them to clear the rail when deploying the legs, if the bipod is mounted with the feet facing backwards.
2/1/06 - From concept drawings a couple of years ago to the production bipod, TangoDown LLC recently released their Advanced Combat Bipod for the M4 (ACB-4). It's not a sniper or hunting bipod that has been adapted for combat rifles, but designed from the ground up for the military as a combat-tough bipod for variants of the M16 system (including SPR or DMRs) . No springs or small parts to lose or poke at you, the ACB-4 works just as well on the shorter M4s and other weapons as well as the longer ones. The ACB-4 was developed over the course of two years with numerous iterations and refinements, testing, and user input from the military.
Bipod body - The clamp body and center portion are forged from 7075-T6 aluminum with Type III hard anodizing. The center portion has two pivots, to which the legs are attached. It will fit on any MIL-STD 1913 rail, using a clamp on the base that is secured by two stainless, black finish screws. An allen wrench or screwdriver can be used to install or remove the ACB. A black stainless button on the outside of each pivot releases and engages a sealed, pre-lubricated stainless steel locking mechanism, which allows the bipod legs to rotate 90° from stowed to deployed. It is locked in both positions and can only be released by puching the button. The center portion rotates for traversing and allows about 40° of angle. The whole bipod body can cant 15°. Urethane bushings keep the bipod center-favoured while allowing it to cant on uneven ground.
Legs - The legs are made up of two pieces - the inner and outer legs. The outer legs house the locking mechanism and button, and have 3 holes/detents which provide 3 height adjustments. The outer legs are made of a proprietary glass-reinforced nylon and are much tougher than they look (I was concerned early on in the design stage when I saw the inner legs, but tried to snap one and I couldn't. The ACB-4 has exceeded Army drop-test requirements). The inner legs are made of carbon-fiber reinforced nylon, and slide in and out of the outer legs. At the top of the inner leg is a button, which fits into the detents in the outer legs. The inner legs are extended by simply pulling them out. In order to shorten them, the button must be depressed and the leg slid in, where the button will engage the next detent. The feet are large to prevent sinking in sand and aggressively checkered for a good grip. When stowed, the bipod legs are locked along the rail system, fitting neatly between the lower and side rails. It will fit most rail systems, and some are shown below. 59ce067264