ABOUT Kaimai® Rifle Suppressors
Kaimai rifle suppressors was formed in early 2014 with the goal of designing and producing a range of lighter weight suppressors, but with better features and durability compared with many other light weight aluminium type suppressors on the market in New Zealand at the time.
The track record for 100% reliability and high performance has been unsurpassed by any other NZ suppressor manufacturer, with the early prototype/trial suppressors still in active service with professional hunters (in excess of 4000 rounds and counting) where with the same type of use some of their previous units seemed to habitually fail in under 800 rounds.
In April 2016 Kaimai Suppressors merged to become part of D.F. Maisey Gunsmithing & Firearm Accessories in Tauranga, to be a valuable addition to the line-up of other high-quality firearm-related products manufactured there.
From July 2017 Kaimai has re-branded to Kaimai® Rifle Suppressors, and this is complementary to the new range of Kaimai Custom rifles produced by D.F. Maisey Gunsmithing, and to recognise our geographical location and local hunting history.
(KAIMAI and Kaimai are registered trademarks of D.F. Maisey Gunsmithing.)
Most centerfire suppressors are designed to reduce about 70% – 80% of peak gunshot noise when firing full-power high-velocity ammunition. Generally, this equates to an approximate 20-32dB reduction when tested with correct sound impulse measuring equipment (with a rise time of 0.002 sec or less). Note: – cheap, general purpose hand-held sound meters are not suitable for testing gunshots accurately. Any dB readings gained with these, or i-phone apps, are essentially worthless and misleading.
Suppressors will not reduce the mechanical noise of a firearm, and it will not reduce the supersonic crack of the bullet (if travelling through the air faster than the speed of sound – @ 330mls, or @ 1080fps).
For full-silent operation, a bolt action or single-shot rifle, with subsonic ammunition and a suitable suppressor/silencer are the minimum requirements.
For most hunting or pest control applications though, most people would use full-power (high velocity) standard ammunition, as this provides a flatter bullet trajectory as well as a more humane and effective method of dispatch to the target-animal in question.
A suppressor is mainly used to reduce the risk of hearing damage to humans and hunting dogs due to the exposure to gunshot sound pressure waves and also to reduce the alarming of other game animals in the nearby area.
Kaimai® Rifle Suppressors are setting a new standard in lightweight tactical performance by taking advantage of this revolutionary alloy and its extraordinary mechanical properties. We don’t believe the consumer should have to choose between the ‘high-strength’ of a heavy steel product versus the ‘light-weight’ of a fragile aluminium one. Tennalum® 7068 offers both, the strength of steel at the weight of aluminium. Although expensive and difficult to obtain, 7068 gives our products an unparalleled strength-to-weight advantage over the competition. When you purchase a Tennalum® product from Kaimai®, you can be confident you’ve reached the pinnacle of lightweight performance.
So what are you truly purchasing in terms of performance? Below is a comparison of how Tennalum® 7068 stands up next to the lightweight alloys used by the rest of the firearms industry.
First a little background – Aluminium (Al) is the single most abundant atomic metal element found in the earth’s crust. It’s a remarkable metal due to its low material density and superb ability to resist corrosion. Pure aluminium, however, is soft, weak, and ductile making it a poor candidate for any high strength application. Though, when mixed with other elements, an alloyed metal can be created with more favourable mechanical properties. The alloyed metal still retains its low density and corrosion resistance but with substantial increases in both strength and hardness. Today, these alloys are used in almost every modern applications where aluminium is found. There are literally hundreds of different alloys that have been engineered and optimized for specific applications.
6061 alloy is one of the most commonly used aluminium alloy today. It is readily available and inexpensive, making it extremely popular for general purpose use. In fact, when you see a product described as being made from ‘alloy aluminium’ or ‘billet aluminium’, or perhaps ‘aircraft aluminium’, but the name of the alloy is not specified, it is a safe bet that it is made from 6061. Virtually all lightweight firearm parts on the market today (optics rails & rings, bottom metal, bolt knobs, etc.) are machined from extruded 6061 alloy. The title ‘aircraft’ aluminium, however, is somewhat misleading since 6061 is not a super-high-strength alloy by any means. With a mere 40 KSI yield strength, it’s use on aircraft is limited to non-critical, low stress components.
7075 alloy is the most common high strength true ‘aircraft’ aluminium alloy used today. Its typical yield strength (73 KSI in the T6 condition) is comparable to certain steels giving the alloy a remarkably high strength-to-weight ratio. In fact, it’s worth noting that its specific strength is comparable to that of 6Al-4V Grade 5 Titanium. However, 7075 is roughly 3-4 times more expensive than 6061. For this reason, it is not as commonly used in the firearms industry as 6061, except in tactical applications where increased strength is a necessity.
Tennalum 7068 Ultra-Strength Aluminium – The Ultimate Alloy
Circa 2000, the Ordnance industry requested development of an ultra-high strength, lightweight alloy with corrosion resistance equal or better than 7075, and with better cracking resistance/toughness than 7075. In response, Tennalum Inc. (a division of Kaiser Aluminum Corp.) developed an ultra-strength alloy called 7068-T6511 – commonly known as Tennalum® 7068. With a yield strength of 99 KSI (683MPa) it has the highest mechanical strength of all commercially available aluminium alloys (2.5 times stronger than 6061, and 35% stronger than 7075 – an alloy commonly referred to in the NZ guntrade as ‘Duralium’) and exceeds that of many steels. In fact, its’ yield strength is approaching that of pre-hardened (HRC 26-32) 41XX and 400 series stainless steels but at a third of the weight. In strength-to-weight ratio, Tennalum® 7068 out-performs nearly all other engineering alloys in existence (33% better strength-to-weight performance than 7075, and 28% better performance than 6Al-4V Grade 5 Titanium). However, due to its higher cost (5-7 times that of 6061) and limited availability, it has seen very little commercial use. But for many applications there is no better alloy, not even Titanium.
In the NZ firearms industry Tennalum® is exclusive to Kaimai® Rifle Suppressors (©2015).