05-07-2011, 08:10 PM
Tony, if it'll help, the following was originally posted by Bill A back in late 2007.
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The attached photograph shows the following projectiles (left to right)
i) 120 grain Berger (Bc=0.492). Thin hard jacket that will fragment easily.
ii)100 grain Lapua Scenar (Bc=0.444). This is the shortest jacket in this projectile class. Note that the nose closure is greater than any of the SMK projectiles and that the lead core is pressed flat on the front. Equally note the jacket weight. The Scenars all have heavy ductile jackets which restrict fragmentation but do deform and tumble.
iii)108 grain Lapua Scenar (Bc=0.478). Shares a common jacket with the 123 Scenar.
iv)123 grain Scenar (Bc=0.547) As above note tip closure, jacket weight and core finish.
v)107 grain SMK (Bc=0.407) The jacket is slightly thinner and is less ductile but the tip closure on this projectile are very close to the equivelent Lapua projectile. Note the formation of the lead core at the front into a standing short cylinder.
vi)120 grain SMK (Bc=0.420) The jacket on this projectile is noticably thinner than the equivelent Scenar and even the Berger. This projectile has the most open tip of the 6.5mm projectiles.
vii)123 grain SMK (Bc=0.510) The construction bar core length is practically identical to the 107 SMK. This round does fragment well in gelatine and the tip is well closed. The core extends further into the jacket nose than the 123 Lapua due to a shorter bullet length and the formation of the short cyclinder on the core front seen on all the SMK.
viii) 115 grain 6.8 SMK (Bc=?) This example is pre canelure but shows a heavy thickening as the nose is formed. The lead cylinder on the core front is still present but the stubby ogive has mainly deformed its presence. The nose is well closed but the airspace at the front of the jacket is present.
ix)115 grain Hornady (Bc=0.320) Current production example. Note the jacket weight and the open tip. There is little airspace within this the jacket nose.
x) 115 grain Hornady (Bc=?) Older production example. The jacket is very noticably thinner than the current bullet and the lead core itself carries a cavity, although this is closed slightly by the action of forming the projectile nose.
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Unfortunately, I don't recall if Scenar gel tests were ever posted. If such can be had, it would give a better representation of what non-fragmenting 6.5mm FMJ wound trauma would be like.
Stan
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The attached photograph shows the following projectiles (left to right)
i) 120 grain Berger (Bc=0.492). Thin hard jacket that will fragment easily.
ii)100 grain Lapua Scenar (Bc=0.444). This is the shortest jacket in this projectile class. Note that the nose closure is greater than any of the SMK projectiles and that the lead core is pressed flat on the front. Equally note the jacket weight. The Scenars all have heavy ductile jackets which restrict fragmentation but do deform and tumble.
iii)108 grain Lapua Scenar (Bc=0.478). Shares a common jacket with the 123 Scenar.
iv)123 grain Scenar (Bc=0.547) As above note tip closure, jacket weight and core finish.
v)107 grain SMK (Bc=0.407) The jacket is slightly thinner and is less ductile but the tip closure on this projectile are very close to the equivelent Lapua projectile. Note the formation of the lead core at the front into a standing short cylinder.
vi)120 grain SMK (Bc=0.420) The jacket on this projectile is noticably thinner than the equivelent Scenar and even the Berger. This projectile has the most open tip of the 6.5mm projectiles.
vii)123 grain SMK (Bc=0.510) The construction bar core length is practically identical to the 107 SMK. This round does fragment well in gelatine and the tip is well closed. The core extends further into the jacket nose than the 123 Lapua due to a shorter bullet length and the formation of the short cyclinder on the core front seen on all the SMK.
viii) 115 grain 6.8 SMK (Bc=?) This example is pre canelure but shows a heavy thickening as the nose is formed. The lead cylinder on the core front is still present but the stubby ogive has mainly deformed its presence. The nose is well closed but the airspace at the front of the jacket is present.
ix)115 grain Hornady (Bc=0.320) Current production example. Note the jacket weight and the open tip. There is little airspace within this the jacket nose.
x) 115 grain Hornady (Bc=?) Older production example. The jacket is very noticably thinner than the current bullet and the lead core itself carries a cavity, although this is closed slightly by the action of forming the projectile nose.
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Unfortunately, I don't recall if Scenar gel tests were ever posted. If such can be had, it would give a better representation of what non-fragmenting 6.5mm FMJ wound trauma would be like.
Stan