Heavy or Light Weight For Cast Hunting Bullets?

[shotstring]

Is the a law of physics which best describes what happens when leading occurs by driving lighter bullets fast vs driving heavier bullets more slowly but with hot gases working on destorting the base longer as it moves down the bore? I've always wondered whether I was better off using heavier cast bullets to impart more energy to the animal without excessive leading from bullet speed.

We know velocity affects leading, and we know that gases working on the base affects leading. There are a host of other things as well, but I am trying my best to just work on these two at the moment. Case in point, with everthing else being equal (bore size, bullet diameter, alloy mix, bbl length, and powder charge, with no gas check) would there be more leading or less leading by firing a 540 gr cast bullet in my Ruger #1 458 as against firing a 350 gr or a 405 gr cast bullet? The 540 grain bullet would be moving at around 1500 - 1550, while the others closer to 1900 - 2000 fps. In reality, the 540 mold is a gas check mold, but for this argument, we are talking about cast bullets without a gas check. Have to imagine a 540 gr bullet that is flat base with no gas check ring for this argument.

[Jack Stanley]

If my choice is the 45 caliber I only have two molds to feed a Marlin 45-70 , one is a three hundred and forty grain LBT flat point . The other is a four hundred thirty grain round nose from Lyman . If my choice is thirty caliber I have more to choose , but I think I would alway choose a bullet heavy enough to leave an exit hole at whatever range I hit the critter .
Medium size animals I think the three-forty would be fine . For critter that weigh a third of a ton I might feel better with the heavies . When velocity goes up I can use a gas check to help things out . To be cheap I'll keep the velocity down .

Jack

[BruceB]

shotstring, amigo;

Seems odd that nobody in this avid bunch of casters AND hunters has yet answered your post.

Without trying to criticize in any way, I think your approach to the question is a bit back-to-front. I'm also working my way toward an efficient cast-bullet hunting load, but I'm approaching it from the IMPACT end....identifying what *I* think I need for performance on a big animal at a given distance.

The "how" part of getting the desired performance boils down to doing whatever I have to do to get there. I set no limits, high or low, on cartridge efficiency, bullet alloy, dimensions, hardness, lube, powder type and powder charge, filler or no filler, gascheck or no gascheck....the field is wide open.

The REQUIRED load for my '08 hunt has:

-a two-alloy cast softpoint, 350-400 grains, the expansion capability of which I must be absolutely confident;

-a trajectory sufficiently flat to ensure effective shooting to 200 yards without much hold-over;

-a level of available energy to ensure performance ON MY PREFERRED TERMS with animals up to possibly as much as 800-1000 pounds.

The rifles are already known, being the Ruger #1 in .416 Rigby or my .404 Mauser. It's possible both rifles will use the same NEI 400-grain bullet at different diameters for the two rifles. Failing that, the .416 will have the RCBS bullet at 365 grains and the .404 will shoot the NEI. Both are gas-checked designs.

In your boat, I'd definitely shoot the 400-grain-class bullet for hunting. There's not much point in firing such a monster as that 540 on most North American game, although it will MOST certainly kill anything here very handily. I'd prefer the flatter trajectory of the 405, and I suspect that you can find a load in the 2000-fps area that will reach 200 yards very nicely. Also, the heavier bullet will probably impart LESS energy to the animal....but energy figures don't do the killing; big holes right through do that.

I think your .458 is a superb cast-bullet rifle for hunting. Many will look at you a bit strangely, but you and I (and a lot of other like-minded gents here) know better, don't we?

There are quite a few Ruger #1/.458-.45-70 shooters in our membership here, and I expect them to chime in soon. I suggest, again, not getting too absorbed in detail about internal ballistics. Leading won't be a problem, especially for the one or two rounds fired at game. Concentrate on what's happening downrange with your load testing, and good hunting!.

[RangerBob]

I'll bet you find that the heavier bullet is more accurate in that gun. I have the exact same rifle and have worked up over 50 different loads for it. By FAR the most accurate bullets are the 500gr+ bullets. I have a few loads with a 375gr or 405gr that shoot OK, but the RCBS 525gr is much more accurate.

Leading has not been a problem with any of the bullets. Accuracy has been a problem with several.

If you try the lighter bullets, try sizing some to .460-.464". This will better fit the huge funnel-shaped throat and aid accuracy. Lighter bullets will likely be more accurate at slower speeds. I can shoot the 525gr to 1900fps with accuracy, but the lighter bullets become less accurate over about 1500fps. If you can get a light bullet to shoot accurately at 2000fps, I would like to know about it . . . as I have not had much luck at this speed.

Good luck.

Bob.

[Lloyd Smale]

Im with ranger bob. I have allways gotten better accuracy in the 4570 and 458 with the heavier bullets especially at long range. Ive never had a leading problem with any of them and it never hurts a thing to error on the heavy side when picking a hunting bullet.

[PatMarlin]

Is this thee beast yee be talkin' bout?...

RCBS 1-Cavity Bullet Mold 45-530-RN 45 Caliber (458 Diameter) 530 Grain Round Nose

[RangerBob]

http://www.gunaccessories.com/RCBS/82054.gif

This link should show you the bullet I'm referring to. It is a GC design.

Bob.

[Ohio Rusty]

I've always been under the impression that for large game, and even dangerous game, that a heavier bullet will impart more trauma to the animal because the weight of the projectile drives itself deeper doing greater damage to stop the internal functions of an animal. To back up my hypothesis .... If you were hit by a VolksWagon Beetle travelling a measly 25 miles per hour, you would be hit with an object imparting 30,000 pounds of energy to your body. Which would hurt worse .... A VW or a Tricycle? I'll stick with heavy ....
Ohio Rusty

[KCSO]

Since I just finished loading a batch of hunting bullets for 30 caliber I will give you my take. You need a bullet heavy enouogh to penetrate to the vitals and with enough meplate to expand in your game. In a 30 I prefer a bullet of over 150 grains for a hunting range of up to 150 yards. My starting bullets in 30 caliber are the 31141 (173 FP) and my all time favorite is the 220 custom FP that I had made at Mountain Moulds. I want either of these bullets to travel at 1900 fps or better and the 31141 in 30-30 at 2000 fps is as good as the jacketed slug for dropping game. I want the bullet cast from an alloy that will expand and I find that #2 alloy or ww and Lino mixed 50-50 do the job. The Lino/ww mix seems to work very well at 2000 or above as it leaves a 2" hole in the off side of everything I have shot with them,except for 1 buffalo. That buff took a 220 to the forehead at 40 yards and the bullet went through the skull and broke the first three neck vertebre before stopping under the skin of the shoulder. It weighed 168 grains and the fragments were distributed in the neck bones. The buff stopped and flopped so I considered this load buff medicine.

In the bigger bores you have to match your bullet to the game. I rarely use over a 330 for deer as my shots are close and with 1-40 l/t I get good expansion at 1350 fps. For Buff you don't need anything over a 400 gr bullet to shoot throuogh and since I don't shoot at 400 yards I don't feel the need for a 535 bullet. A deer or a Buff is a BIG target and if you can hold 6" at a given range that is how far off you can shoot. My 45 Sharps will hold 6" at 300 yards with a 400 grain bullet and I can still get a little expansion. Most of my shots on game are at 100 or less so I plan on 200 to be on the safe side. The problem I see with the 500 bullets on DEER is that they punch straight through with little expansion and don't leave a large enough exit hole. The 330 Gould H/P leaves a pretty big hole on the off side and the more blood that leaks the more apt I am to get a deer.
Where I hunt if the deer crosses the fence you might not get to claim him even if he is stone dead, hence my preference for maximum damage.

[Ghugly]

Is the a law of physics which best describes what happens when leading occurs by driving lighter bullets fast vs driving heavier bullets more slowly but with hot gases working on distorting the base longer as it moves down the bore? I've always wondered whether I was better off using heavier cast bullets to impart more energy to the animal without excessive leading from bullet speed.

We know velocity affects leading, and we know that gases working on the base affects leading. There are a host of other things as well, but I am trying my best to just work on these two at the moment. Case in point, with everything else being equal (bore size, bullet diameter, alloy mix, bbl length, and powder charge, with no gas check) would there be more leading or less leading by firing a 540 gr cast bullet in my Ruger #1 458 as against firing a 350 gr or a 405 gr cast bullet? The 540 grain bullet would be moving at around 1500 - 1550, while the others closer to 1900 - 2000 fps. In reality, the 540 mold is a gas check mold, but for this argument, we are talking about cast bullets without a gas check. Have to imagine a 540 gr bullet that is flat base with no gas check ring for this argument.

While it irks me that I paid for what amounts to 719 pages of Richard Lee promoting the wonders of his skills and genius, there is some interesting tidbits of information to be found in Modern Reloading, Second Edition. Mr. Lee proposes that accuracy and leading, when shooting cast boolits, is not the product of velocity or heat but chamber pressure. His reasoning is, that while some distortion of the boolit is necessary and desirable, too much pressure for the alloy used will cause poor accuracy and leading. He includes a chart listing the maximum pressure for boolits cast to Brinell Hardness numbers from 8.0 to 36.6. By his chart, air cooled Linotype (assuming a BHN of 22) should be used at around 28,000 PSI, water quenched WW of 30 BHN, around 38,000 PSI. If one had heat treated boolits at the top of his chart, 36.6 BHN, they should be best at or slightly below around 47,000 PSI. There are some cartridges that should push a boolit to near 4,000 fps at 47,000 PSI. I find it hard to believe that that can be done with accuracy and without leading.

I am not, in any way, promoting Mr. Lee's book or his proposal. I do, however, find it interesting.

[Ricochet]

Like many other theories, that one's oversimplified. Doesn't take into account rifling twist (centrifugal and shear forces) or frictional surface heating. You're likely to run into problems pushing a cast bullet to 4000 FPS, even if the pressure to hardness ratio fits on the chart OK. But it's still a useful help for many applications.

[PatMarlin]

" If one had heat treated boolits at the top of his chart, 36.6 BHN, they should be best at or slightly below around 47,000 PSI.."

Huh? I have the book and I don't follow?

I'll show no shame in promoting it... It's one hell of a great reference on cast and condom bullets. More usefull info on shooting cast than anything out there as yet in determining loads, safe reduced loads, and estimating pressures for cast.

So he gloats about his history and products in the first sections. So what- he is damn sucessful, and to me earned the right to gloat. Wether or not an idividual agrees with the same enthusiasm is another story... :mrgreen:

My point in posting is don't let your opinion of LEE's products get in the way of your maybe picking up a copy of his book. It is a damn fine work, and has gone to greater lengths then most in helping us cast shooters.

The above note is specially geared towards new cast shooters.. :drinks:

[45 2.1]

There is nothing wrong with lighter boolits at long range in 45 caliber rifles. The problem is that the current makers do not make them large enough. A properly fitted boolit shoots a lot better than you think it will and there are no flies on penetration when it is alloyed and heat treated correctly. Case in point is the following mold. Note the possible boolit combinations in it.

[PatMarlin]

Ho!!! That is a sweeet mold 45!!! I want onna those.. :drinks::drinks::drinks:

[45 2.1]

Ho!!! That is a sweeet mold 45!!! I want onna those.. :drinks::drinks::drinks:

Wanting and actually paying what the maker wants is two different things. Quality is expensive.

[Blammer]

I'm no help on the big boolits and calibers you shoot.

But for my 357 mag and 35 Rem, I'd feel more comfy with 180 to 200 gr boolits traveling slightly slower than a 150 class traveling a bit faster. Big heavy and slow is where it's at when shooting lead, IMO.

[Ghugly]

" If one had heat treated boolits at the top of his chart, 36.6 BHN, they should be best at or slightly below around 47,000 PSI.."

Huh? I have the book and I don't follow?

I'll show no shame in promoting it... It's one hell of a great reference on cast and condom bullets. More useful info on shooting cast than anything out there as yet in determining loads, safe reduced loads, and estimating pressures for cast.

So he gloats about his history and products in the first sections. So what- he is damn successful, and to me earned the right to gloat. Werther or not an individual agrees with the same enthusiasm is another story... :mrgreen:

My point in posting is don't let your opinion of LEE's products get in the way of your maybe picking up a copy of his book. It is a damn fine work, and has gone to greater lengths then most in helping us cast shooters.

The above note is specially geared towards new cast shooters.. :drinks:


I enjoy the book, and I agree that Mr. Lee has been a huge benefactor to the shooting world in general and to cast shooters in particular. Like many, my first taste of the world of hand loading was with using a Lee Loader. Mine was in the early 70's loading .38 special and .357 Mag. I don't know if I would have tried hand loading if I had been stuck with the initial investment of a press + dies + scale +, +, +, etc. That loader made hand loading cheap, made shooting cheap, made it possible for me to practice often and with a lot of good, reliable ammunition, that I was proud to use. I've since gone on to a lot of other makers equipment although I still use a goodly percentage of Lee. So far (knock on wood), I have never had a piece of Lee equipment that did not work nor had the feeling that I would have gotten more for my money with another maker's product. That could change tomorrow, of course.

I am somewhat irked by the fact that I paid for what amounts to an enormous add. I also balk at buying hats or Tee shirts that promote someone's product or service (if they want me to advertise for them, let them supply the hat). I really get annoyed when I pay for a movie ticket, take my seat, and get blasted with adds.

The reference I made to hardness/pressure was from the chart on page 134. He lists a Max pressure of 46,900psi for a boolit cast to a hardness of 36.6BHN. Earlier in the book, he explains that one should try for a load with a pressure that "approaches 90% of the Ultimate Compressive Strength of the alloy." My intention was to show that not every authority agrees that velocity is the limiting factor when using cast boolits, and that Mr. Lee seems to believe that if you can keep pressure to within the limits imposed by the strength of your alloy, some impressive velocities can be successfully achieved.

[shotstring]

At least I think Lee's argument is going somewhere. Chamber pressure and the resulting boolit distortion makes perfect sense to me at least as another factor to add into the equation. It certainly explains to me why you can have equal or greater leading with a heavier bullet traveling slower as against a lighter bullet flying down the bore. Thanks for all the food for thought. Now if I could just find a place to shoot close to home to try out all this theory. :(

[PatMarlin]

" The reference I made to hardness/pressure was from the chart on page 134. He lists a Max pressure of 46,900psi for a boolit cast to a hardness of 36.6BHN. Earlier in the book, he explains that one should try for a load with a pressure that "approaches 90% of the Ultimate Compressive Strength of the alloy." My intention was to show that not every authority agrees that velocity is the limiting factor when using cast boolits, and that Mr. Lee seems to believe that if you can keep pressure to within the limits imposed by the strength of your alloy, some impressive velocities can be successfully achieved."

OK I found it, thanks.. :drinks:

[leftiye]

Not to disagree on any of what has been said, but to state my opinion that other factors cause leading than boolit softness and/or high load pressure. There is also the rate (point in the boolits travel) at which the pressure increase attains its highest level, this modulates the effect of the pressure greatly. Also, the raw velocity itself, though affected by pressure, and the shape of the burning curve does eventually exceed the point that leading due to friction, or lack of a good enough lube, or a rough barrel, or other factors can be prevented from causing leading. It isn't necesary to deform the boolit with pressure to get leading.

Conversely, obturation (deformation) which occurs due to pressures higher than the plastic limits of the lead can prevent leading by sealing the bore to gas cutting. Especially if the pressures reach the plastic level just as or just after the boolit engraves.

R. Lee's limit of pressure to the plastic limits of an alloy apply to all pessures less than the plastic limit, only pressures over the limit cause deformation. There is nothing that says we have to approach those pressures for any reason (should be used at those pressures) other than velocity, and a flatter pressure curve that never approaches this limit can produce higher velocities in some cases than pressures that are higher still (than the plastic limit of the alloy) which deform boolits, but produce lower velocity overall due to shorter duration/ higher peak burning curves.

[Bret4207]

As to the original question- heavy, preferably with a FN or RNHP.

[Ghugly]

R. Lee's limit of pressure to the plastic limits of an alloy apply to all pressures less than the plastic limit, only pressures over the limit cause deformation. There is nothing that says we have to approach those pressures for any reason (should be used at those pressures) other than velocity, and a flatter pressure curve that never approaches this limit can produce higher velocities in some cases than pressures that are higher still (than the plastic limit of the alloy) which deform boolits, but produce lower velocity overall due to shorter duration/ higher peak burning curves.

I would refer you to page 136 of Modern Reloading, Second Edition. In this test it was demonstrated that the best accuracy is achieved at a point just prior to the ultimate compressive strength of the alloy used. He suggests 10% below the ultimate compressive strength of the boolit for maximum accuracy. The main point that I am able to glean from Mr. Lee's work is, for the best overall performance we should select the proper alloy for the pressure we are using. That does not conflict with what I have read from the learned members of this forum. I have often read that the hardest alloy is not always the best alloy. In low to moderate pressure cartridges, wadcutters, for example, or cowboy type loads, a softer alloy, even approaching pure lead can give the best accuracy. If this were not true, I guess most of us would be using heat treated linotype for every cartridge that we were loading for maximum accuracy. Mr. Lee is saying that there is a scientific method that will get us in the ballpark when selecting the proper alloy for the job. Conversely, if we have boolits of a particular alloy, we can use this formula to help us choose the best powder and charge for the cartridge.

Back to the original question. I think it depends largely on what you intend to kill. I took a 40lb sow with a 405gr boolit from a .45-70. It was absolutely the wrong choice if you like pork ribs. On the positive side, there was no need for a follow-up shot.:)