LIGHTEST BULLET FOR 243Win w/ 8" twist

[Methow Packer]

Hey. My 243Win shoots 105VLD really well with its 8" twist barrel. If I would want to shoot a litter weight bullet suitable for coyotes n stuff how light could I go with this twist barrel. Thinking about stabilizing, etc.

 

[BryanLitz]

I don't think there is a lower bullet weight limit for fast twist barrels. Sure the bullet will be way more stabilized than it needs to be, but where's the harm in that?

As it happens, I was recently shooting a test that involved .243 caliber 70 grain SMK's and a 1:6" twist barrel 243 Win. Granted, I wasn't pushing velocity to super max (I was around 3300 fps) also the SMK jacket is a little thicker than some varmint bullets. Regardless, I would bet you could push most any lightweight 243 varmint bullet to max velocity in an 8 twist 243 with no ill effect.

-Bryan

 

[Bart B]

It's my experience that light bullets of poor quality (pulled M80 7.62 NATO bullets) ) spun too fast leaving the barrel (max load in .300 Wby Mag with 1:10 twist) shoot less accurate than well balanced ones (Sierra 150 HPMK). The higher centrifugal forces cause them to jump off the muzzle axis upon exit from the barrel. Those M80 bullets shot a lot more accurate in a 21" long 1:12 twist .308 Win sporter barrel; almost as good as the Sierra HPMK's.

A friend of mine spun some 30 caliber 185-gr match bullets in a Dremel Moto tool holding a collet shaped to hold them point in. An amp meter was connected inline on the power cord. At 30,000 rpm, the unbalanced ones drew more current than the perfect ones. A few were so bad they flew out of the collet bouncing off the ceiling and walls of the shop they were tested in. 10-shot test groups were fired from a machine rested .308 Win. rifle at 600 yards. Perfect bullets' groups ranged from 1.5 inch down to 0.7 inch. A 40-shot group was 1.92" extreme spread. Some of the unbalanced ones' groups were over 10 inches. Go figure that out. That brand and bullet types back then were well known for having a few in each box of 100 that shot far away from point of aim.

 

[roninflag]

My 8 twist krieger barrel will shoot everything i have tried which on the low end was 68.

 

[Kansaswoodguy]

As long as you find a powder that the light pills like I do not think you will have any issues. A buddy has trouble with 35gr out of a 22-243 wildcat but they come apart I dought with a 243 you can push any bullet fast enough to make that happen.

 

[Methow Packer]

Thanks to all for your responses. Your answers have helped me understand clearly that I can work with some lighter bullets with this barrel. Good news!

 

[newmexkid]

I am awaiting my new 6-284 and was thinking about the same question.

 

[Frank in the Laurels]

I have a friend who shoots a .243 AI full house with the 8 twist , he was shooting an unnamed bullet and they were disintegrating about 20 feet after leaving the barrel, this was witnessed by lots at the Mifflin co groundhog march, never aw anything like that happen before, guess the jacket just couldn't take the velocity and that fast of a spin...it was really cool, I guess the metal went to the plasma state, all you saw was a shimmer similar to oil on water ..at first he couldn't figure out why he wasn't hitting the target..someone else who said it may remember it..love to see that again !!

 

[JackinSD]

I have a friend who shoots a .243 AI full house with the 8 twist , he was shooting an unnamed bullet and they were disintegrating about 20 feet after leaving the barrel, this was witnessed by lots at the Mifflin co groundhog march, never aw anything like that happen before, guess the jacket just couldn't take the velocity and that fast of a spin...it was really cool, I guess the metal went to the plasma state, all you saw was a shimmer similar to oil on water ..at first he couldn't figure out why he wasn't hitting the target..someone else who said it may remember it..love to see that again !!

Been there done that. 58gr VMAX after the barrel warmed a bit. Got about 6-7 shots perfectly and then a cloud of dust about 20 yards down range.