June 29th, 2010

New Generation Tactical Rings Offer Innovative Clamping Designs

TacticalRifle.net Chimera Titanium RingsWe recently had a chance to test the new Chimera Titanium Rings from TacticalRifles.net. The Chimera Rings are “ultra-premium” items designed to compete with the very best tactical rings on the market. As you’d expect, they’re expensive. The 30mm Chimera Rings retail for $224.00 per matched set, including Torx driver. Though these fat boys are beefy in size, offering 7.5 square inches of clamping area per set (way more than most rings), they are very light weight. A medium-height, 30mm Chimera ring weighs just 84 grams (2.96 ounces).

The Chimera rings are precision-machined to exacting tolerances. We had our Mark, our in-house machinist, check them out and he was very impressed: “These rings exhibit beautiful fit and finish and are extremely tough. The fit of the ring bases on a Picatinny rail is perfect. I liked the radius shapes given to most of the surfaces. The front and back faces of each ring are standard flat planes, and the ring caps have a flat disc in their centers, but the remainder of the cap and the sides of the bodies are gently curved. This design requires sophisticated machining processes to pull off, but it looks good. The larger-than-standard heads on the cap hardware, 8-32 X #25 Torx, are another departure that looks well thought out. One danger this increased head size would present if the fasteners were threading into typical 6061 aluminum bodies would be the potential to over-torque and strip the threads with the larger #25 Torx wrench. However, since the titanium bodies have approximately double the tensile strength of 6061 aluminum this is not a problem.”

TacticalRifle.net Chimera Titanium RingsAssymetrical Tensioning by Design
The Chimera Titanium Rings employ an assymetrical clamping design. This should allow the rings to provide stronger clamping force with less chance of ring distortion. Here’s how they work. After placing the scope in the lower halves of the rings, you screw down the top halves on one side only (opposite the bolt head that clamps to the Picatinny rail). After the three Torx screws are tightened fully on one side, so that the top Ring half butts firmly on the bottom half, there will still be a small gap on the opposite side of the ring (see photo). Don’t worry — that is by design. Final torque is applied to the side with the gap. With the final tensioning done on one side only, the scope is less prone to twist. Furthermore, the manufacturer claims this design puts less stress on the scope tube during mounting.

TacticalRifle.net Chimera Titanium Rings

We did fit the Chimera rings to a Leupold LRT 8-25x50mm scope with 30mm tube. Fit was excellent with no high or low points. With the rings installed as instructed, with one side first clamped flush and the opposite side then torqued to spec, the scope was very secure. On removal the Chimera rings left no visible marks on the tube. I can’t say that it would be a waste of time to lap these rings, but on our Leupold scope the fit was perfect, and the “grip” was uniform over the entire clamping surface.

TacticalRifle.net Chimera Titanium Rings

Tactical Precision System TSR™ Rings
TSR™ rings made by Tactical Precision Systems (TPS) have a clamping design very similar to the Chimera Titanium Rings. After placing the scope in the TSR ring set, you clamp down one side (of the ring tops) until metal meets metal. This then leaves a gap of 0.020″ on the other side. The TSR Picatinny 30mm 7075 Aluminum Medium Rings cost $82 in aluminum or $94.00 in alloy steel. The TSR rings are narrower than the Chimeras, and have two Torx bolts per side, rather than the three on the Chimeras.

TSR Rings Tactical Precision

M3 Hinged Scope Rings from American Rifle Company
An even more radical clamping system is employed by the new, patent-pending M3 Scope Rings from The American Rifle Company. The top section of the M3 rings is attached with a hinge on one side. After placing the scope in the bottom section of the M3 rings, you swing the upper ring half into place over the scope tube. Then the clamping is done with two inverted (head-down) machine screws that actually pull the hinged ring section downwards. This is designed to put less stress on the scope than conventional rings. The axis of the screws is tangential to the scope tube. Sophisticated finite element analysis (FEA) was used to develop the “over the top”, tangential-clamping ring design. According to the manufacturer, this design evenly distributes clamping forces over the tube and “eliminates the damaging effects of [scope] bending”. The manufacturer claims that, with its rings, “no significant stress concentrations are present on the scope tube”. American Rifle Co. backs up these claims with a series of 3D stress analyses published on its website.

TSR Rings Tactical Precision

Credit The Firearm Blog for reporting on the M3 ring design.
Disclosure: TacticalRifles.net loaned a pair of Chimera Titanium Rings for testing and evaluation.

Permalink Gear Review, New Product, Optics 2 Comments »
June 29th, 2010

U.S. Army Issues New M855A1 Ammo to Troops in Afghanistan

The U.S. Army has begun shipping its new, improved 5.56×45 cartridge, the M855A1 Enhanced Performance Round, to U.S. troops in Afghanistan. The Army will procure over 200 million rounds of the new M855A1 ammo in the next 12-15 months, and soldiers in Afghanistan will begin using M855A1 ammo in the summer of 2010. The new round replaces the current M855 cartridge used by U.S. troops since the early 1980s.

M855A1 ammunition ammo EPR

The military sought to replace current M855 ammo because M855 has not performed adequately in the Afghan theater. Specific complaints include: 1) inability to effectively penetrate vehicle windshields; 2) poor long-range performance; and 3) failure to fragment even in short-range anti-personnel use. The Army’s Picatinny Arsenal claims that the new M855A1 has improved hard target capability, more consistent performance at all distances, improved accuracy, reduced muzzle flash, and higher velocity. M855A1 ammo is tailored for use in M4 carbines but should also give enhanced performance in M16s and M249s.

M855A1 ammunition ammo EPRNew Steel-Tip Bullet Design
The 62-grain bullet for the new M855A1 ammo is a completely new design. While it may appear to have a plastic “ballistic tip”, that’s deceiving. The new bullet created for M855A1 ammo has a bismuth-tin alloy core with a steel “stacked-cone” penetrating tip. The photo at right shows the version from last year; the final production version may be slightly different (e.g. the final version tip is a different color). Apparently the latest bullet design is a winner. During testing, M855A1 ammo performed better than current 7.62mm ball ammunition against certain types of targets. According to Lt. Col. Jeffrey K. Woods, the program’s product manager, the new M855A1 ammo is “the best general purpose 5.56mm round ever produced. A true general purpose round, the M855A1 exceeds the performance of the current M855 against the many different types of targets likely to be encountered in combat.” The chart below illustrates how M855A1 ammo performs on hard targets compared to M855.

M855A1 hard target

Over One Million Rounds Fired in Army Tests
Prior to initial production, the new M855A1 round underwent vigorous testing. Official qualification of the round consisted of a series of side-by-side tests with the current M855. Overall, the Army fired more than one million rounds to ensure the new cartridge met all expectations. The new M855A1 round is the “most thoroughly tested small caliber round ever fielded” according to Lt. Col. Woods. The new M855A1 is sometimes called “Green Ammo” because it uses a lead-free projectile. Woods said the M855A1’s bullet design shows how “greening” a previously hazardous material can also provide extremely beneficial performance improvements.

Permalink Bullets, Brass, Ammo, New Product, News 14 Comments »
June 29th, 2010

Creedmoor Sports Offers One-day 54¢ Shipping Promotion

To celebrate the U.S. Supreme Court’s 5-4 ruling in McDonald v. Chicago, Creedmoor Sports is offering a special, one-day 54¢ Shipping Sale. For today only, June 29th, ANY Creedmoor Sports order, no matter how big, will ship for just $0.54. (Ammunition and bullets excluded!) To get your discounted shipping visit CreedmoorSports.com, and Use Coupon Code: 5-4VOTE.

Creedmoor Sports Sale

Conditions: Sale today 6/29/2010 only. Not subject to prior sales. Shipping coupon excludes ammunition and bullets. These items will be charged shipping before the order is processed.

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