30 cal turned heads

qqqq33 · #1 05-01-2009, 02:12 AM

ok experts why hasnt anyone just turned a longer monometal bullit for the 30 cal. Wouldnt that give it a higher bc. please give pros and cons and what to becareful of. I have the means to turn my own. was thinking of using a 338 lapua turned down to 30 cal

FEENIX · #2 05-01-2009, 05:44 AM

Quote:

Originally Posted by qqqq33

ok experts why hasnt anyone just turned a longer monometal bullit for the 30 cal. Wouldnt that give it a higher bc. please give pros and cons and what to becareful of. I have the means to turn my own. was thinking of using a 338 lapua turned down to 30 cal

I'm no expert but here's my WAG, ... time and $$$ vs ROI. With today's bullet design, I just let the barrel do the turning.

.

Good luck!

EddieHarren · #3 05-01-2009, 06:27 AM

There's a fellow, over on AR, that is lathe turning solid copper bullets and having great success with them.

RockyMtnMT · #4 05-01-2009, 06:38 AM

I think that the limiting factor is the required twist to stabilize the bullet. You need to get up into the 8 or 9 twist to handle the long bullets. There really isn't any factory barrels out there that are that fast, so the market for the really high bc 30 cals is very limited. Also if you set up a rifle to handle the long bullet, it may not function well with conventional bullets.

Just my .02, Steve

BountyHunter · #5 05-01-2009, 07:50 AM

Almost everyone of those type bullets have had issues with barrels. Seems that you have to go thru gyrations finding exactly the right twist, right groove diameter, bore diameter combos etc to get a barrel to work.

BH

Michael Eichele · #6 05-01-2009, 06:59 PM

The properties of jacketed lead produce much higher BC's than solid copper. Length for length, design for design, shape for shape, jacketed lead will always have a higher BC than a solid copper bullet. If you made a bullet of the same length and dimensions as the 240 SMK, the SMK will have it beat by a fair margin, plus the all copper would require a tighter twist to boot. IMHO, solid copper is NOT the place to be looking for a ultra high BC bullet. Yes it will take more length to get the weight up and the theoretical BC should be higher but it really isnt. Length is NOT the only factor in a BC. Material density is also a big part. In short, a 240 grain all copper and 240 grain jacketed lead bullet of the same style might have very similar BC's but it is going to take alot of length to get that all copper bullet up to 240 grains. The additional length of the all copper will not offer you more BC than the SMK. You will also need a MUCH tighter twist to handle the length AND the all copper properties and for a BC that is no more than that of the 240 SMK.

It seems like alot of money, time, effort and un-needed rifle torque for nothing in return.

Now if you were talking solid lead, then the opposite would be true. Better yet, solid tungsten, but then again, barrel life would really suck if you used solid tungsten.

RockyMtnMT · #7 05-01-2009, 08:38 PM

Quote:

Originally Posted by Michael Eichele

The properties of jacketed lead produce much higher BC's than solid copper. Length for length, design for design, shape for shape, jacketed lead will always have a higher BC than a solid copper bullet. If you made a bullet of the same length and dimensions as the 240 SMK, the SMK will have it beat by a fair margin, plus the all copper would require a tighter twist to boot. IMHO, solid copper is NOT the place to be looking for a ultra high BC bullet. Yes it will take more length to get the weight up and the theoretical BC should be higher but it really isnt. Length is NOT the only factor in a BC. Material density is also a big part. In short, a 240 grain all copper and 240 grain jacketed lead bullet of the same style might have very similar BC's but it is going to take alot of length to get that all copper bullet up to 240 grains. The additional length of the all copper will not offer you more BC than the SMK. You will also need a MUCH tighter twist to handle the length AND the all copper properties and for a BC that is no more than that of the 240 SMK.

It seems like alot of money, time, effort and un-needed rifle torque for nothing in return.

Now if you were talking solid lead, then the opposite would be true. Better yet, solid tungsten, but then again, barrel life would really suck if you used solid tungsten.

I may be dead wrong, so someone correct me.

To my reasoning an all copper bullet of the same weight and shape as the 240 SMK will be a longer bullet w/ the same shape. Has to have a higher bc. An all copper bullet that is of the exact same dimension as the 240SMK would be lighter with very nearly the same bc, slightly less. Substantially lighter means substantially faster velocity. To my way of thinking the faster slightly lower bc bullet will out run the slower slightly better bc farther than you can accurately range find.

If I am wrong, I need someone much smarter than I am to explain it for me.

Steve