Why so big?

[Lost Dog]

Just curious. Being basically old school, I cast, load, and shoot bullets that were the "norm" some years ago. You know; 158gr to 173gr in .38, 230gr to 245gr in .44, 150gr to 175gr in .30 cal. But here I see dozens of ya'll casting rounds much heavier and often several thousands of an inch larger in diameter than a few years ago was considered average.
Is this a result of shooting iron silhouette or mould makers marketing? Enlighten me.

 

[Rick]

Can't speak for anyone else but in my case it was momentum on target. A 158 gr 35 caliber bullet from a 357 will not take down a 55 pound 200 meter ram. Plus a heavy for caliber bullet with as slow a powder that will achieve the desired velocity makes load work up for long range accuracy all the easier.

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[JWFilips]

As far as Diameter goes: I have found all my cast bullet rifles shoot better with a .002" to .003" oversize bullet ie. .226" in my .223, .246 in my 243, .326" in my 8 mm Mausers and .360" in my 35 remington:
but I shoot mostly light loads for target shooting

 

[Rick]

For diameter my 357 revolver gets bullets sized .357". My 30-30 however gets sized to a minimum .3105", .3115" is all the better.

 

[JWFilips]

.3115" is all the better.

I forgot about that one! My old Marlin 336 likes them there or even .312" if my alloy is soft

 

[Rick]

My 30-30 has quite a nice bore, all 26 inches of it. Well, except for that pesky .310" groove diameter. I can only assume Winchester figured if they started with over size tooling by the time it wore down it would be just right. Mine must have been one of the early bores done with that tooling. Any bullet sized smaller than that will lead the bore. This rifle also left the factory with no throat cut, none, nada.



That was the beginning of the rifling as photographed through a bore scope, the first thing the bullet saw when the big light came on. I suspect this is why I got such a nice rifle so cheap, nobody could make the thing shoot. A few minutes with a throating reamer and all is well. Still has a .310" bore though.

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[yodogsandman]

For the 35 Whelen, I wanted full penetration on a moose. The 35 Thumper bullet should do it. A 250 gr Nosler Partition did not when it encountered the shoulder ball. I did find it just under the skin on the offside, though. The 35 Thumper has the same sectional density as a 45 caliber, 500 gr but, is smaller in diameter.

In the .308 (7.62x51), I've been trying "normal" weights. I like heavy weights for it still, over 180 gr.

Want to run smaller than normal weight for most calibers I shoot because less lead is used.

Diameters of all bullets are sized to just under the throat sizes, whatever the bore diameter in rifles are.

 

[RicinYakima]

Military cast bullet target shooters shoot at 100, 200 and 300 yards. The longer the bullet, the less wind drift. The heavier the bullet the less it slows down, and we try to keep the bullet above the speed of sound by 5%. Military rifles shoot smaller groups if the bullet is sized to the size of the throat, and not the bore size.

 

[Brad]

Depends on the need.
As a couple guys here have mentioned sometimes a heavier than usual bullet just works better.
I prefer to look at it this way. Bullet weight is determined by the desired result. A hunter isn't a 357 mght well want a 180 gr bullet while a guy using the same rifle for cowboy action may use a 125 to reduce recoil.

One size definitely does not fit all.

 

[fiver]

if you can't go fast might as well go heavy.
energy on target is energy on target if you can't get it through speed you only have weight left to make it up.
plus semi-slow and soft is a darn dangerous combination in the woods or on the porch.
I shoot mostly nominal weights in my guns.
158's in the 38's
240's in the 44's
250-270's in the 45's
200-230 in the acp.
200's in the 44-40
etc.
but I too stray off track, just for fun sometimes, with a specific purpose in mind other times.
160's in the 45 colt just makes sense when all I'm doing is making a ding noise at 25 yds with the USFA's, or when I want to shoot a 2 pound grouse, or 20 lb turkey at 30 yds with the lever gun while I'm deer hunting.

now a 315gr 3/4 jacket [made from 40S&W brass] in the 445 under 35 or so grains of 1680 is more along the lines of a short barreled rifle load.
it also works great for short range deer/elk hunting.
it'd for sure do long range but I can't.

 

[Lost Dog]

Yeah, I'm definitely not from the itty bitty little bullet school of thought. Thus my disgust of the little black rifles. I like big chunks of lead going down range. But never got into the über heavy rounds though. Was satisfied with standard weight rounds of caliber appropriate level.

 

[Rick]

if you can't go fast might as well go heavy.
energy on target is energy on target if you can't get it through speed you only have weight left to make it up.

Not quite that simple. If you double bullet weight at the same velocity you double momentum on target. If you double velocity with the same bullet weight momentum on target increases by 25%. To match momentum with only velocity you need to increase velocity by 400%.

Momentum is measured in pound seconds. To figure out pound seconds . . .

Multiply the bullet weight in grains by the velocity at impact. Divide the product by 226,000 (a gravimetric Constant).
Example: 45 caliber 240 grain bullet 200 yard velocity of 985 fps. 240 x 985 = 236400 divided by 226,000 = 1.046 pound-seconds momentum.

To reliably take down a 55 pound properly set 200 meter ram 0.8 pound seconds of momentum is needed. you can do the math to see how fast that 45 caliber bullet would need to be going. The simple bottom line, bullet weight for momentum on target. In addition as has been said already, the heavier bullet by carrying more momentum looses less original velocity over the course of the range.

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[Ian]

Not being in the sport, I never had a need to calculate pound seconds but that's interesting anyhow, now that you've explained it.

I'm with Fiver, if you can't go fast, go heavy. Why can't you go fast sometimes? Well, there's the sound barrier thing if you own silencers. Also, there's the perceived recoil thing (sharp recoil bothers me more than slow, hard recoil, i.e. a .243 Winchester hurts me while a .358 Winchester putting down three times the energy hardly bothers me at all), and dropping velocity in favor of lobbing more mass seems to work out to a more comfy load. Sometimes you HAVE to go heavy if you want it to go at all, i.e. subsonic 300 blackout in an AR-15 which won't cycle the action with less than about 200 grains of bullet and often needs 220 grains to be reliable.

I load 100 grain all the way to 247 grain bullets in my .30-30s, with quite a few stops in between, some loaded mild and some "loaded for bear". .35 Remington sees 150 grain and 220 grain bullets. My .45 Colt carbine sees 340-grain paper-jacketed bullets loaded over a full case of RX-7 for 1325 fps....Trapdoor Springfield territory.

Variety is the spice of life.

 

[fiver]

it's definitely not all that simple.
but that's how I try to keep things.


you know you gotta read the threads around here all the way through.
you never know what tip or math figure or just what all is gonna pop up in the middle or back of a thread.

 

[Lost Dog]

Well this has been educational. Figured the iron silhouette crowd would go heavy for the punch. Knew from my own experience that fast little bullets can't compare to the power of the moderate speed of a larger round. Much like the difference of a person throwing a pebble at you and then tossing a baseball. One's gonna sting and maybe even do some damage, but the other's gonna hit harder and hurt more. Maybe even break something. So I suppose using a bowling ball is like the real heavyweight bullet. Super knockdown power.

So longer, heavier bullets fly farther and straight. Knew that from BP cartridge weapons. Big heavy pistol rounds smack harder and don't shed their velocities as fast as lighter ones. And basic physics dictates that mass in motion favors larger heavier objects over smaller lighter objects. Ok. Doubt I'll ever use any formulas, but interesting none the less. So I learned things here. Thanks guys.

 

[9.3X62AL]

My bullet diameters start at throat diameter with a new-to-me arm or casting, and sometimes adding a partial or complete thousandth helps grouping. I haven't leaded a barrel in a long time.

I use very few "lighter than standard" weight bullets, either jacketed or cast. Most are "standard" weight-for-caliber or heavier. These have shot better and more consistently for me historically than have the lighter/faster projectiles.

 

[KHornet]

I have always been pretty much a standard weight from times past for most ctgs. That said, I now shoot more 125 gr Lee in 38-357 than I do most other weights because it is accurate, cheap to shoot and saves me 25-50 gr of lead per round, not to mention recoil. And of course there is the fact that I am cheap, or frugal depending on who is making the statement. I have shot round ball in just about every ctg that I have ever loaded, and gone to the max plus weights available for most ctgs that I load. When I find something I like I will stay with it! Different strokes for different folks!

 

[Lost Dog]

Yes sir, been contemplating on a shorter 38 bullet now for my Rossi. Shot some 173gr Keith SWC's through it yesterday and it was beyond stupid how bad it was. Some commercial made 157gr RNFP shot great. Shorter bearing surface was my take on it. Don't think long and heavy will work in this Rossi. So a 125gr to a 140gr RNFP would likely do better.

And as to round ball shooting, sure. I run em through the sizer and load em up with some beeswax over em. Light loads of pistol powder and away we go!