Posted: 11/6/2011 2:00:48 PM EDT
| Following on from Timlads thread about ammunition, what's the consensus on bullet weight. Should you go for the heaviest your barrel twist can handle for max. performance in wind? |
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Following on from Timlads thread about ammunition, what's the consensus on bullet weight. Should you go for the heaviest your barrel twist can handle for max. performance in wind? Well the heaviest in 223 is 77gn and because of BC is also the best in the wind....... |
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77 grain Sierras are the heaviest mag length bullets you can get. They are the way to go if you reload. However as they travel slower than Nato 62 grain ammo there isn't a HUGE difference in wind performance between the two. The surplus stuff (62grain) is almost as good due to the extra speed and hence shorter flight time for the wind to push it off.
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77 grain Sierras are the heaviest mag length bullets you can get. They are the way to go if you reload. However as they travel slower than Nato 62 grain ammo there isn't a HUGE difference in wind performance between the two. The surplus stuff (62grain) is almost as good due to the extra speed and hence shorter flight time for the wind to push it off. Interestingly, I've just run a comparison between a77gn SMK @ 2700fps and a 62gn SS109 @ 3000fps At 300yds in a 10mph cross wind the 77 will drift 9.54" and the 62 9.57" Because the 77 has a higher BC, it loses less speed and whereas time of flight for the faster 62gn bullet at 300yds is 0.35s, the 77 is 0.39. So nothing in it except that farther back the heavier bullets will have a more distinct advantage and as they are match grade, should group better |
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Quoted: Quoted: 77 grain Sierras are the heaviest mag length bullets you can get. They are the way to go if you reload. However as they travel slower than Nato 62 grain ammo there isn't a HUGE difference in wind performance between the two. The surplus stuff (62grain) is almost as good due to the extra speed and hence shorter flight time for the wind to push it off. Interestingly, I've just run a comparison between a77gn SMK @ 2700fps and a 62gn SS109 @ 3000fps At 300yds in a 10mph cross wind the 77 will drift 9.54" and the 62 9.57" Because the 77 has a higher BC, it loses less speed and whereas time of flight for the faster 62gn bullet at 300yds is 0.35s, the 77 is 0.39. So nothing in it except that farther back the heavier bullets will have a more distinct advantage and as they are match grade, should group better At what range does the difference start to show up markedley? |
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Beyond 300...... The 77's are definitely better at 500 and 600. The figures would try and disprove that, but we all know the 77,s are better at those distances. The 77's also retain a lot more energy too. If I'm shooting just for fun I'll shoot 62's, when it's important to me it'll be 77's. Incidentally I have about 40 88gn may length SMK's. They were experimental bullets, but were found to be too heavy and slow to gain any advantage in a service length barrel, as are the 90's |
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Beyond 300...... The 77's are definitely better at 500 and 600. My 69 grain Sierra BTHP seemed to manage ok at 600. Though, I might try the 77's The 69s are a great bullet but the 77s are a bit better, and for the extra small amount in cost is it really worth taking second best? |