So my precision rifle is a old Remington 700 varminter in 243. These guns had really slow twists so i can really only run up to 75 grain bullets to get the best accuracy. Do you think switching to a solid copper bullet thats 75 grains would be worth it as it would increase the length of the projectile making it more aerodynamic?

EDIT: Im shooting vmax's at .33 a pill vs what would be a 1.04 a pill. Is it worth it for long range (1200yds)

To get an idea about the "aerodynamic" nature of your chosen bullet, look at the BC.  Do copper bullets have a better BC?...  last time I checked, the answer was "no"...  In addition, the longer bullet may require a faster twist rate to stabilize it...  This is why you don't hear many distance shooters talking about copper bullets - they don't offer any external ballistic advantages and may require a slightly faster twist rate to stabilize a bullet of the same weight when compared to jacketed lead bullets.

I just tried some monolithic solid copper bullets in my .260 Tikka and even though they were supposed to be stable in a 1:8 twist they weren't.  I used 5 different powders and info recommended from the vendor but just couldn't get them to stabilize.  After shooting all the bullets I went to Bergers website and put in the info about the bullet in their "Twist Rate Stability Calculator" and found the bullet would was outside the stable range.  I would at least use their calculator before you buy the bullets.

Jason

Rate of twist is matched with the length of the bullet, not weight.  In a normal lead bullet the length is directly proportional to the weight.  When you change the material, and density, of the bullet that proportionality isn't true.

So no, you can't use a longer copper bullet even if its the same weight as a stable lead bullet.  The longer projectile won't necessarily be stable.

No !

Bullet stability is based on L E N G T H not on weight ! It just so happens that gilding jacketed bullets filled with lead have the property that in a given caliber, a given weight will all end up being "about" the same length. But Bullet stability remains based on L E N G T H.

Monolithic bullets are INVARIABLY longer (well not if you make them out of Tungsten or Uranium, but I digress), so for the length of bullet you barrel stabilizes, you need a lighter monolithic bullet than your gilded lead bullet.

ok thanks for the info guys! Guess I should just stick with the vmax

Will it do the 87 vmax? It's been a while but I seem to remember it being decent for being light.

If not just shoot what you got. I've seen plenty of guys with light varmint guns tear it up.