Copper Target & Hunting Projectiles

Cutting Edge Bullets have designed their solid copper projectiles to be the most accurate, fastest and flattest shooting projectiles on the market, providing better downrange performance than any other premium match grade projectiles. CEB projectile designs were created using proven data like that from well respected modern ballistician, Bob McCoy. They were then tested using custom rifles built by well known rifle builder, Bruce Baer, as well as in standard factory rifles.

Cutting Edge Projectiles makes an extensive line of low drag high ballistic coefficient target projectiles suitable for competition shooting and long range matches. There is an extensive selection of projectile weights in the popular calibres. These projectiles are lathe turned from solid copper and have higher degrees of concentricity, dimensional and weight consistency than is possible from swaged projectiles. This makes them very accurate for the demands of competition.

Design Features

Extreme Uniformity – Lathe turned on Swiss Style sliding headstock CNC machines from a solid copper rod, the projectiles are extremely consistent in terms of uniformity and weight, leading to excellent accuracy. They are precise from lot to lot with the maximum weight deviation of .4 grains on MTH, MTAC and FBH projectiles. All CEB solid copper projectiles are within .0001" in concentricity and .00015" in diameter. All projectiles types are inspected rigorously at appropriate intervals and documented accordingly, ensuring that all are the same dimensionally, regardless of when they are manufactured.

Copper Mono-metal Construction – CEB lathe turns their projectiles from a solid copper rod, using is also the most barrel friendly type of copper available. It is softer than most typical gilding copper used by some manufacturers of solid copper projectiles. Fouling is minimal due to no blow-by of hot gasses escaping around the projectile which softens the copper and will cause barrel plating. Unfortunately, it is also the most expensive type of copper, but the quality of the materials used is worth the extra few cents on each projectile.

SealTite Band (STB) - The SealTite Band is a feature unique to CEB solid copper projectiles. It is the key to making our projectiles shoot without the fliers common with some other solid copper or copper alloy projectiles. It is larger than nominal calibre diameter by .0005" to .005" depending on calibre. This ensures that no gases escape around the projectile when fired, which drastically reduces copper fouling and helps in producing match grade accuracy and consistency. The STB position can be customised to allow for a different projectile projection length. There are however, limitations on how far forward the band can be positioned.

Material Displacement Grooves (MDG) - The MDG serves two functions. Firstly, they provide space for the copper to flow into when the STB enters the throat and lands in the rifle barrel. This prevents excess pressure as the soft copper flows freely into them. Only a very minimal amount of material is displaced. There is only .001" per side on diameter that is displaced which is approximately 1/3 the diameter of a human hair. Secondly, they also act as an indicator as to where the STB is actually at which is helpful for projectile seating.

Meplat - The meplat (or bullet point) portion on lead core hollow point projectiles are often very ragged and uneven sometimes requiring pointing and trimming operations in order for an individual to be competitive in match shooting. The meplat on all Cutting Edge Bullets projectiles are always perfectly round and flat eliminating pointing and trimming operations. Cartridge overall lengths can be precisely measured without the need for special gages.

Ogive - Almost all Cutting Edge Bullets projectiles incorporate a tangent ogive and are designated 'LD' for low drag. The tangent ogive configuration was chosen to make the bullets much easier to tune and means they are not nearly as sensitive to seating depth as the secant ogive configuration. Another important aspect of tangent ogive projectiles is their ability to maintain ballistic coefficient (BC) to much greater distances than the secant ogive bullets. In most cases, if a tangent ogive is optimised for maximum BC, the trajectory will overtake a secant ogive, or very low drag (VLD) projectile's trajectory well before they drop to 1400fps even though the VLD projectile starts with a higher BC. Some VLD (secant ogive) projectiles are available from CEB in a few calibres and weights, but are recommended for shooting only to 900 metres.

Bore Rider Design – The front portion of the projectile from the ogive to the driving band is slightly (.0001" - .0003") smaller than actual rifle bore size. It allows maximum projectile projection for maximum charge capacity, and reduces friction and therefore pressure. It also aids in aligning the projectile to the bore and prevents ogive contact with the lands when chambering projectiles that protrude far out of a case.

Driving Band – The portion of the projectile that is between the SealTite Band and bore rider or ogive. The driving band engages the rifling lands, ahead of the SealTite Band and aligns the projectile to the rifling before the SealTite band is engraved. As it is absolutely critical that the projectile is properly aligned before SealTite Band engagement, CEB projectiles are tested to ensure the driving band is long enough to prevent 'stripping' and loss of seal. Since gas seal is achieved by the SealTite Band, the driving band diameter on CEB projectiles is under nominal calibre diameter to prevent excess pressure.

Boat Tail – The projectiles designed for long range shooting all incorporate a tapered heel (boat tail) rear portion. Boat tail designs take longer to stabilise (or 'go to sleep') ad are best suited to ranges of 400 metres or more. At longer ranges the boat tail provides a higher BC and so projectiles retain their energy much better than flat base projectiles. While boat tail projectiles do not fully stabilise in less than 300 metres they may still group well. However, for shorter ranges, flat base projectiles are a better choice as they stabilise quicker than boat tailed projectiles.

Range of Weights – Most calibres have a range of bullet weights for the, allowing the shooter to select the right bullet weight for their intended range, barrel twist rate and application.

 

Caution!

It is extremely important that if you have a custom barrel made undersized, the driving band diameter must first be measured to ensure it is smaller than your groove diameter, or you will get excess pressure. Solid copper does not 'give' like lead core projectiles and custom size barrel users must be very cautious. Any SAAMI spec. or factory rifle barrel will not have this problem. The Driving Band length can be customised to allow for more or less jump into the throat to bore angle.

A Note on Ballistic Coefficients

At this point the Ballistic Coefficients of CEB projectiles are not exact but are not exaggerated. CEB arrived at the stated BC's by using muzzle velocity and actual projectile drops at various ranges and calculated them using Oehler's Ballistic Explorer 6.2.0 software. While this is not precise, anyone that has shot long distances will see the difference in drop when compared to the projectiles you are currently shooting. In time CEB will obtain more precise BC's by using an Oehler 43 or Oehler 83 chronograph with acoustic targets set at ranges out to 700 metres. The ranges will be certified and the ballistic coefficients will be very accurate. Eventually, to get even more accurate, CEB will have data obtained by using Doppler Radar as well. This data will be found on CEB's website, Facebook page and Twitter account. As with most projectiles and especially with VLD designs, the use of multiple BC's may be required for CEB projectiles, especially at very long ranges for better accuracy. However, where variable BC's are not provided in the projectile descriptions, the posted BC will get you within 1/2 MOA even at very long ranges.

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