U
uplandfam
Guest
I'm not from as far south as you all but the angeles ranges out side of LA has a 500 yard public and a rental available for 1000 I think but bLM would be way more fun.
Ballistic coefficient
- Thread starter Bowman
- Start date
http://southerncaliforniahunting.com/huntersforum/index.php/topic,5958.0.html
I believe the BLM land is out until they open it up again.
I believe the BLM land is out until they open it up again.
Hi guys! Great Thread!
As a .260 Rem owner and crazy scientist, I thought I would share my thinking when I selected the .260 Rem. Mind you this was back in 2006, before many of the great 6.5mm cartridges we have today. But I think the fundamental logic still holds up, for me at least.
To me it all goes back to the human equation, if we were all the Terminator and could handle a phase plasma rifle in a 40 watt range then we would just shoot big fast cartridges, but I for one do not like recoil, and I do not shoot high recoil rifles well. I know there are folks out there that can, and to them I tip my cap.
My goal is to reach 1000+ yards with a rifle I enjoy shooting, and with the .260 Rem I feel I have done that. To me it is the perfect balance of recoil, and ballistic performance. Every engineering endeavor is about compromise, and every rifle makes compromises, in my experience the majority of shooters do not shoot heavy recoiling rifles well, so design a rifle with less recoil. Where does the recoil equation meet the ballistic equation? I have found, and I think many agree the 6.5mm bore allows enough weight and ballistically efficient bullets and manageable recoil for the vast majority of shooters in rifles that are comfortable to carry.
So for a apples to apples comparison lets look at 3 bullets, a 130g 6.5mm (.264") (Norma) a 168g 7mm (.284") (Berger) and a 200g 7.62mm (.308") (Berger) bullets. All 3 of these bullets have a G1 BC of about 0.600. If we launch each bullet at 2900 fps they will have virtually the same trajectory. So what cartridge will we have to use to get that muzzle velocity, and what will the recoil be like. In 6.5mm I know I can start the 130g Norma at 2900 fps because I do it on a regular basis, it's my long range .260 Rem load. For the 7mm bullet you need to use a 7mm Rem Mag and for the 7.62mm (.308) bullet you need a .300 Win Mag. Both the 7mm Rem Mag and .300 Win Mag recoil a lot more than the .260 Rem and require a long action rifle. Obviously they will deliver more energy on target.
The real question is, do you really shoot a big magnum as well as a light recoiling .260 Rem? This depends on the shooter, for me the answer is no. Keep in mind that some of the best match shooters have been switching to the 6.5mm bore because in a 60+ round match they find they shoot better toward then end of the match because they have not been getting pounded by their rifle. No specific bullet diameter can elude the laws of physics and magically give a better trajectory, but you can get a similar trajectory for less recoil with a smaller bullet to a point. At the end of the day I can shoot my .260 Rem as much as I want without starting to flinch. After 4-5 rounds, with the bigger rifles I start to flinch. Be honest with yourself because you owe it to the animals your hunt, shot placement is the number 1 MOST important factor in a clean humane and responsible hunt, don’t compromise your shot placement for magnum chest hair! Impress me with tiny groups, not big bangs!
Now the above analysis is for copper jacketed lead core bullets (cup and core). With cup and core bullets 3000 fps is a good muzzle velocity, go much faster and you start to shorten barrel life, and risk bullet failure if you are hunting and get a close range shot. Cup and core bullets are over 150 years old, so is there any improvement in bullets since then? What is the 21st century bullet and how can it change the design compromises we balance when we pick our rifle and cartridge combination?
Just my opinion, but the 21st Century bullet is solid copper and turned on a CNC lathe. These bullets are very tough and will not fail at extreme impact speeds, if designed correctly they reduce barrel wear, can have very good ballistic efficiency, and use the energy they strike the target with much better than older designs. This allows the use of smaller faster bullets in all the cartridges, helping reduce recoil. Times are changing and we all have to reexamine our preconceptions about cartridge and bullet choice. The exciting part is so many new options are opening up!
I still think 6.5mm is a great bore, and will do almost anything a hunter could want in North America. The new bullets give any cartridge at least one step up the ladder of performance, so your .308 will perform more like a .300 Win Mag, and 300 Win Mag like a 300 Ulta Mag. The new bullets are not cheap, but worth every penny. I try to find a sweet spot by using smaller bullets.
Keep up the great conversation guys!
As a .260 Rem owner and crazy scientist, I thought I would share my thinking when I selected the .260 Rem. Mind you this was back in 2006, before many of the great 6.5mm cartridges we have today. But I think the fundamental logic still holds up, for me at least.
To me it all goes back to the human equation, if we were all the Terminator and could handle a phase plasma rifle in a 40 watt range then we would just shoot big fast cartridges, but I for one do not like recoil, and I do not shoot high recoil rifles well. I know there are folks out there that can, and to them I tip my cap.
My goal is to reach 1000+ yards with a rifle I enjoy shooting, and with the .260 Rem I feel I have done that. To me it is the perfect balance of recoil, and ballistic performance. Every engineering endeavor is about compromise, and every rifle makes compromises, in my experience the majority of shooters do not shoot heavy recoiling rifles well, so design a rifle with less recoil. Where does the recoil equation meet the ballistic equation? I have found, and I think many agree the 6.5mm bore allows enough weight and ballistically efficient bullets and manageable recoil for the vast majority of shooters in rifles that are comfortable to carry.
So for a apples to apples comparison lets look at 3 bullets, a 130g 6.5mm (.264") (Norma) a 168g 7mm (.284") (Berger) and a 200g 7.62mm (.308") (Berger) bullets. All 3 of these bullets have a G1 BC of about 0.600. If we launch each bullet at 2900 fps they will have virtually the same trajectory. So what cartridge will we have to use to get that muzzle velocity, and what will the recoil be like. In 6.5mm I know I can start the 130g Norma at 2900 fps because I do it on a regular basis, it's my long range .260 Rem load. For the 7mm bullet you need to use a 7mm Rem Mag and for the 7.62mm (.308) bullet you need a .300 Win Mag. Both the 7mm Rem Mag and .300 Win Mag recoil a lot more than the .260 Rem and require a long action rifle. Obviously they will deliver more energy on target.
The real question is, do you really shoot a big magnum as well as a light recoiling .260 Rem? This depends on the shooter, for me the answer is no. Keep in mind that some of the best match shooters have been switching to the 6.5mm bore because in a 60+ round match they find they shoot better toward then end of the match because they have not been getting pounded by their rifle. No specific bullet diameter can elude the laws of physics and magically give a better trajectory, but you can get a similar trajectory for less recoil with a smaller bullet to a point. At the end of the day I can shoot my .260 Rem as much as I want without starting to flinch. After 4-5 rounds, with the bigger rifles I start to flinch. Be honest with yourself because you owe it to the animals your hunt, shot placement is the number 1 MOST important factor in a clean humane and responsible hunt, don’t compromise your shot placement for magnum chest hair! Impress me with tiny groups, not big bangs!
Now the above analysis is for copper jacketed lead core bullets (cup and core). With cup and core bullets 3000 fps is a good muzzle velocity, go much faster and you start to shorten barrel life, and risk bullet failure if you are hunting and get a close range shot. Cup and core bullets are over 150 years old, so is there any improvement in bullets since then? What is the 21st century bullet and how can it change the design compromises we balance when we pick our rifle and cartridge combination?
Just my opinion, but the 21st Century bullet is solid copper and turned on a CNC lathe. These bullets are very tough and will not fail at extreme impact speeds, if designed correctly they reduce barrel wear, can have very good ballistic efficiency, and use the energy they strike the target with much better than older designs. This allows the use of smaller faster bullets in all the cartridges, helping reduce recoil. Times are changing and we all have to reexamine our preconceptions about cartridge and bullet choice. The exciting part is so many new options are opening up!
I still think 6.5mm is a great bore, and will do almost anything a hunter could want in North America. The new bullets give any cartridge at least one step up the ladder of performance, so your .308 will perform more like a .300 Win Mag, and 300 Win Mag like a 300 Ulta Mag. The new bullets are not cheap, but worth every penny. I try to find a sweet spot by using smaller bullets.
Keep up the great conversation guys!
There is no secret, magic or special caliber. Shape and sectional density are pretty much something you can scale up and down. All things equal, a bigger diameter bullet with the same shape and sectional density and velocity will have a higher ballistic coefficient, have less drop at a given range and retain a higher percentage of initial energy. Bullet availability and size of available cases with enough powder capacity to drive the bullet fast enough and recoil put limits on how big you can go and get the same velocity with a given sectional density bullet. Nice thing about the smaller calibers is that they don't beat you into flinching and use less powder and lead. It's all about tradeoffs and the best caliber is subjective.
EF said:
In other words, what you are trying to say is the 6.5mm is King. I can read between the lines! ;D
Snake Charmer
Happiness is a warm gut pile
Not sure of the weight - 25" barrel. Fine Firearms has the Sako's that are 9 lb with a scope. And the Tikka's should be a little bit lighter. Weight is your friend regarding long range shots...