Originally Posted by Dongle
Tried the 200gr Nosler Accubond, group well.
And the 200gr Woodleigh PP, seems 200gr is the weight for this calibre. Also tried some 220gr woodleigh but couldn't get velocity.
With the woodleigh I hollow point them myself. I've spoken to a few blokes who tell me they can be a bit hard and go through without expanding, so for a bit of insurance I hollow point. As yet it only theory because I've yet to take one.
Use re17 with the Nosler (2911fps) and AR2009 (2816fps) with the Woodleigh
I would forget about the small velocity difference between the 200 and 220 grain bullets.
The Sierra Gameking will make up the small difference very quickly.
The Woodleigh would be OK for close range work under 200 yards but forget about it for long range stuff. They have the form factor of a brick!
For long range work the the 200 grain Nosler Accubond has a lower recomended impact velocity limit of 1800 fps. That will be reached at 625 yards with your 2911 fps load and have a retained energy figure of 1440 ft/lbs.
The 220 grain Sierra Gameking is a soft bullet. With its higher B.C. it will hit 1800 fps lower limit at 675 yards with the 2816 fps load that you stated. Retained energe is 1565 ft/lbs. This bullet would most likely work at well below 1800 fps.
The Sierra also has less wind drift at long range which is very important when taking long shots at sambar in the alpine areas.
I have shot over 200 sambar with various calibres and seen many more taken by mates with all sorts of calibres including the 8x57 which is a very slow cartridge. All kill sambar very well up close, it is the long range performance that seperates them.
Below is part of an article that I am currently writing for the aussie magazine. It is unfinnished at this stage put gives two scenarios that highlight the difference between various shooting situations.
In the first scenario, the system will consist of a .300 Winchester magnum. The load is a 180 grain Accubond bullet at a muzzle velocity of 2950 fps. Energy of 3878 ft/lbs. Velocity variation is + or - 30 fps. The rifle is capable of 1 MOA accuracy at 100 yards from a solid shooting position.
The environmental conditions involve flat country at an elevation of 600m, 10 degrees C and 78% humidity. Wind is blowing 10 mph at right angles to the line of fire.
The game animal is a Fallow Deer Buck with a generous side on vital zone of 12 inches high and 18 inches wide. The .300 WM with this load is more than powerful enough for this size game animal and the bullet is a recognized reliable game bullet.
Nosler recommends a minimum impact velocity on game of 1800 fps. So with the use of the Exbal ballistic program, the maximum distance that this bullet can be shot at and still be above the 1800 fps limit is 740 yards. Energy at this range is 1300 ft/lbs. This bullet may still expand below 1800 fps, but for this exercise we will accept it as correct. So 740 yards is maximum distance that you can shoot, based on average retained velocity. But this is not the only limiting factor.
Lets look at the inherent accuracy of the rifle. It can shoot consistently at 1 MOA with cold bore shots. With a velocity variation of +or- 30 fps and a time of flight of 0.964 seconds the theoretical vertical group size at 740 yards is 13.5". This theoretical group size is based on mathematical formula.
As the possible group size is larger than the 12" height of the vital zone, a new maximum distance has been calculated at 680 yards. This distance can be reduced even further if the topography includes hills that may induce a vertical wind component. A vertical component of only 1 mph has a +or-3" effect on elevation depending on up or down draft. The effect of this vertical wind component would be to reduce the maximum range of a reliable precision shot down to 600 yards.
Now lets look at the horizontal component of the vital zone with regard to inherent accuracy and wind. Without any wind our calculated horizontal group size at 600 yards is 7.5". Now given that no one is perfect at reading the wind even with wind meters, we will assume a wind reading accuracy of +or- 4 mph over the length of the shot.
With the estimated 10 mph wind strength +or- 4mph, the effect on wind drift at 600 yards is from 14" at 6 mph to 32.5" at 14 mph . That makes the possible horizontal component a massive 26" this is well outside the 18" vital zone. To remain inside the 18" horizontal vital zone limit the distance must be reduced even further to 490 yards.
Now lets imagine that the Fallow Buck was facing towards the hunter at an angle of 45 degrees. This would effectively reduce the horizontal size of the vital zone from 18" down to about 13". This would reduce the maximum range down to about 400 yards.
Most hunters quote the muzzle velocity, energy and 100 yard accuracy of there pet rifle to guess the maximum effective range of their rifle. From this simple exercise, it can be demonstrated that these are poor indicators and that the environmental conditions have a far greater effect on long range performance.
This exercise only used calculated values, in the real world things like rifle cant and an unsteady shooting position can also have a significant effect. Other things like animal size, anatomy, bullet construction, slope error, range finder error and equipment quality can effect maximum range.
This is what "Precision Hunting" is all about, staying within your limits and shooting with the confidence of knowing that you will make a clean shot.
A lot of the information shown in the exercise above can be worked out prior to the hunter even entering into the field. He should have a good idea of the maximum effective range of his shooting system from his field practice sessions. He will then be able to adjust his maximum shooting distance based on the measured field conditions when hunting.
Lets have a look at another situation using a popular modern calibre under ideal conditions. This time we will be shooting a 7mm Magnum from a high quality, precision long range rifle with a heavy 28" barrel. The rifle is fitted with an anti cant device and an angle cosine indicator. The match grade ammunition is loaded with a Berger 180 grain hunting bullet at a muzzle velocity of 2950 fps +or- 7 fps and an energy value of 3480 ft/lbs. This rifle is capable of consistent 0.5 MOA accuracy from a solid rest.
The hunter will shoot under the principals of precision hunting. The Fallow Deer Buck will be standing side on. He will measure the shot with a Swarovski rangefinder and calculate the aiming solution using G7 B.C. values. Atmospheric values will be measured using a Kestrel weather meter. He will then wait for the deer to be standing still and undisturbed prior to the shot.
Again using the lower velocity limit of 1800 fps to ensure proper bullet expansion, we can calculate our maximum range. In this case we reach the lower velocity limit at a range of 1000 yards.
The vertical group size at this range is calculated as being 9.2" high and 6.5" wide. This is a perfectly reasonable level of accuracy for a rifle of this quality under these conditions.
The vertical component in this case is under the 12" limit and the horizontal component is well under the 18" limit. So in this case the factor that limits our maximum range is the retained velocity of the projectile.
However the shooter should always be aware of other errors. One of the most common errors is in reading the distance with the rangefinder. Care must always be taken when using rangefinders that you are reading to the right spot.
Comparing the two scenarios, it is obvious that the most powerful cartridge is not always the best. Precision accuracy, good ballistic knowledge and only shooting when conditions are right will ensure a successful outcome.