What makes a caliber "cast friendly"?

[geargnasher]

Periodically there are threads about "favorite" cast boolit calibers, easiest to load for, etc., but lately I've been pondering just what it is that makes a particular cartridge more easy to "dial in". I've come up with a lot of things, I'd like to hear what other's thoughts are on the subject.


1. In pistols, low-pressure rounds like .38 Special, .44 Special, .45 ACP, and .45 Colt seem to be the easiest to load for. Naturally, lower-pressure rounds tend to work better with our softer lead alloys because they aren't stressing and deforming the boolits so much. Many of these were originally loaded with lead boolits, and much of the factory stuff today is still loaded with lead. In other words, they were more or less designed for lead boolits in the first place, and have thinner brass than some of the modern, high-pressure, jacketed-oriented cartridges do. Reloading die specs seem to be more cast-friendly for some cartridges than others, too. I have yet to see a .40 S&W expander die with a correctly-sized spud, except for the one I had custom-made. The high-pressure cartridges like 9mm, .40, .357 Sig, and .380 are the big challenges. Thick, hard brass built for high pressure and dies designed for jacketed bullets seem to be the main culprits causing the difficulties.

2. In rifles, it seems that the same holds true. 45/70 Gov't and 30-30 Winchester are always favorites, but look at the pressures. Even hot 30-30 loads are far less than modern caliber pressures designed for jacketed bullets. While just about every cartridge out there has been loaded with cast boolits, some seem just taylor-made for cast. I hear the "long, thin neck" thing a lot, and tend to agree. I wonder, though, why doesn't the fantastic .303 British, which has an excellent case design for cast, enjoy the same stellar reputation as the .30-30 does for the task? Most of you here know the .303 is fundamentally an excellent cast boolit cartridge in just about any platform, Enfield or otherwise, but that knowledge doesn't seem as prolific elsewhere. Then take the .30-'06 Springfield, a much-beloved cast boolit cartridge, and study it a minute. WHY? Ok, long neck, mass availability of components and guns, but what else? I find it ok for cast, but most of the time it's loaded to .30-30 levels at best. Is that achieving the best efficiency? I hardly think so. The .30-30 about maxes the "easy" cast boolit velocity and accuracy potential of the .30 caliber boolit, which makes me inclined to hold it in higher esteem, unless of course you're talking full-snort, 2700 FPS paper-patched boolits.

So what is it that makes a cartridge "best"? Is it low pressure limits of the cartridge that keep things inherently in the "cast friendly" pressure range? Is it particular attributes of the case design itself? Tooling specs? Is it the guns commonly chambered for it? Is it nostalgia, or history, or the fact that a given round was touted by famous people? I think it all comes into play, but the bottom line is that the aggregate experience of generations of cast boolit shooters arrive at the same conclusions over and over, and there has to be a "best" reason for their opinions. I have mine, I'd like to hear yours.

Gear

[ScottJ]

I'm still relatively new to this but I think diameter has something to do with it too. For example it is easier to get into true magnum levels with the .44 plain base than the .357.

[tomme boy]

One of the reasons I think the 303 Brit is not used more is the condition of the rifle to begin with. The bore on these rifles are all over the place. I have seen a few with a almost perfect bore an it measured at 0.317". Then the next on that is a sewer pipe ran at 0.314". I like them, but they were just too picky to find something that shot well.

That and it is not a US cartridge, so it will never have the fame of the 30-30 or the 30.06

[Linstrum]

Hey, geargnasher, interesting topic. I've been here a long time and from my own personal observation this subject hasn't come up as often as others.

I'll play devil's advocate a bit because one way to analyze what makes a good "cast friendly" cartridge is to take a look at what makes some cartridges "cast un-friendly". You already mentioned the high pressure pistol cartridges, which often also employ high rates of twist compared to black powder era pistol cartridges. I know the .357 Magnum was never a black powder cartridge, but it is based on one, so compare the 9mm Parabellum's 1 in 10-inch twist with the .357 Magnum's more or less 1 in 18-inch twist. For me, the .357 Magnum is a good cast performer in both revolver and rifle, while cast in the 9mm Parabellum gives me a lot of trouble in my pistols.

rl 1089

[MtGun44]

ScottJ,

Not in my experience. With good fit, good lube and good designs, I shoot full power .357
mag all the time with soft alloy, great accy and no leading. try 358477, the RCBS near
clone, 38-150-K (now named 38-150-SWC), Lee 358-158RF, or Elmer's 358429.

All work great in 8 to 14 BHN range, no GCs, accurate and no leading.

.44s and .45s about the same, really. Good fit, good lube, good designs and you can run
full power without GCs or super hard alloys.

Bill

[geargnasher]

Linstrum, I've thought about it plenty from that angle, too, but admit I never considered the part about twist rate in 9mm being much of a factor. Trying to get cast boolits to shoot straight in .270 Winchester at anything over 2K fps or loading for the .243 Winchester and .300 Winchester Magnum at all (Maybe it's a Winchester thing:shock:) have proven to be a little tougher than, say, the venerable old .30-30 or the .300 Savage. Harder brass, short necks, short throats with abrupt lands, fast twists, etc. seem to make some of these more of a challenge, whereas 20 years ago even this dumb kid at 17 was cramming 311407s sized to .311" (accidentally got the correct die!) in his Marlin and sending them merrily downrange with 10.5 grains of Unique to collide with closeout-sale diet canned sodas and rotten oranges by the case, rarely missing at 70 yards sitting with shooting sticks. I didn't know about cleaning lead out because it never happened to me. Same with .38 Special, I shot buckets of wheel weights (no tin added) through my revolver, cast with a reshaped soup spoon, iron skillet, and Lee moulds, sized in a push-through and lubed with a turtle-wax/LLA concoction, and didn't own a micrometer. A few years later I bought my first new pistol, a 1911 in .45 ACP. That one accounted for several buckets of wheel weights itself, all loaded with Lee dies in a green single-stage press, and through thousands of rounds of IDPA I never had a jam or a misfire that I can recall. Since then I've branched out, and quickly discovered that they aren't all as easy as that, and if you want tiny groups downrange you'd better start doing a lot of reading, measuring, and buying of precision tools to get satisfaction. For example one of my sporterized Swedes will shoot 1.5", ten-shot groups at 200 yards with boring monotony (if I do my part and the wind is calm) with Sierra J-words, but won't hold 2" at 100 consistently with any cast load I've put through it at half that distance, at any speed. I have several other rifles that are pure, accurate joy to shoot at long ranges with cast boolits, but some pretty close attention to equipment, components, and alloy, together with a lot of experimentation (mostly general learning curve on my part) was required to achieve it. Even then, some calibers are easier than others, even in almost identical platforms.

Shooting cast boolits can be a short road or a long road to happiness, and in my experience the length of that road has a whole lot to do with the cartridge designation whether you're green or seasoned. I've been pondering off and on just why that is ever since.

Gear

[RU shooter]

I dont know if its one of the best for cast bullets ,But for me the 35 Rem. in my model 600 has shot just about any cast bullet and load combo I have tried with acceptable hunting accuracy from plinking loads up through full power cant fit anymore powder in the case loads. Why I dont know ? Its neck isnt all that long so that aint it. I would have to say it is maybe due to the slow 16 twist and a well cared for barrel and also the lower pressures it operates at even at full power loads. Even my 32 spl. has been more temperamental with different loads. Im not even close to being a cast bullet "expert" so I dont know why it shoots good just happy it does!

Tim

[btroj]

I have had good luck in my 270 Win but I have never tried for velocities over 2K either.
The 303 has one big problem, it isn't commonly found in commercial rifles in the US. If someone made a nice lever action or a commercial bolt gun in 303 it would find more fans in the cast world.

I do think part of what makes some of the "easier" to work with cast cartridges so easy is that they have a long tradition of cast bullet usage. Me have many, many decades of info on what works well for so many cartridges. 30-30 and 45-70 have always been favorites of cast shooters, that makes them easy to find information on. 45 ACP and the revolver cartridges have the same advantage.

I have had some sucess with a 300 Savage bolt gun with cast but only have used one bullet. The RCBS 165 SIL bullet has the advantage of having a long bore ride nose and a short bearing area, this makes it work with the very short neck.

Some comes down to expectations too. We are happy with a 30-30 loads that goes 2K fps but we want a 243 to go 2500 fps. If we can live with the 243 at 1800 it can be made to shoot quite well.

Some is powder capacity too. A 45-70 or 30-30 can be easily shot with cast at very cast friendly pressure with a full case of powder. That isn't the case with some of the more "modern" cartridges with large powder capacity for the bullet diameter. I have always though a 30 BR would be about the ideal cast cartridge for a 30 cal bolt gun.

[kenyerian]

"Some comes down to expectations too. We are happy with a 30-30 loads that goes 2K fps but we want a 243 to go 2500 fps. If we can live with the 243 at 1800 it can be made to shoot quite well."
i think that btroj hit the nail on the head. Acceptable accuracy in some calibars is notacceptable in others.

[shooting on a shoestring]

In my opinion, the factors that add to cast friendly are pressure, twist, case capacity and physical size.

Pressure and twist been covered.

Case capacity, need enough but not too much. Think .380 vs .38 Spl. .380 has such a small caes capacity there are only a few powder/boolit combinations to work with. .38 Spl, well the door is open as to powder selection and boolit weight (length). On the other end look at 30/30 vs .300 Win. The 30/30 case will hold large enough charges of slow powder to get to the normal top end of boolit speed, but yet not have an excessive amount of empty case volume with charges of more normal powders like 2400 or RL#7. The .300 Win would need as much filler as powder to keep a charge of 2400 in place to expect much of a group. Filler brings in a whole nuther level of complication/problems.

Physical size. I'm thinking how many cast 17 cals? I cast and know that casting .22s is as small as I can work with. Temps get much harder to control, blemishes are more critical, size variation, heck any variation has more showing on the target than a .30 cal.

[Linstrum]

Geargnasher, you said a lot! So far, some characteristics that have been identified are things like if it were a black powder cartridge originally, the particular platform used (kind of gun), case dimensions, useful powder volume, shoulder angle, neck length, rate of rifling twist, throat dimensions, leade/free bore/rifling start ramp angle, and operating pressure. Kinds of boolit designs could be another topic because this one is pretty complicated in its own right. What else can we add to the cartridge characteristics list? I know rifling rate of twist isn't part of cartridge data, but rates of twist used with some specific calibers have been standardized to some degree, like 1 in 10" for the 9mm Parabellum is pretty common and may lead to troubles with cast.

What could also be another subject are the various platforms that lend themselves to cast. For examples, bolt guns are probably the best. Some autoloaders work quite well with cast, too, like the M1 Garand and its "little brother" the .30 M1 carbine. So does the good old 1911A .45. Then there are those that don't.

About Swede Mausers, they are kind of in a class by themselves. From what I can tell, the Swedish Mausers give everyone fits including me and an awful lot has been written about them here, including some unpleasant contentious debates. My own opinion about why the Swedes are hard to shoot cast boolits in is basically because of the large powder capacity with a small bore diameter in conjunction with an extremely fast 1 turn in 7.5-inches rifling twist that was originally used to stabilize the long-for-caliber 140 (and 160?) grain bullets that the Swedish military used. Because of that, cast boolits just don't do too well over about 1500 fps, although with special care, super slow powders like WC860, IMR7828, or IMR5010, strong alloys like linotype, and a good lubricant, I have read that they can get up to around 2100 fps with acceptable accuracy. I use a Saeco 140 grain linotype boolit sized 0.002" over bore diameter with 46 grains IMR5010. I don't know the velocity, but it has acceptable accuracy. When I cranked it up a notch with 47 grains of powder everything went to pieces with some boolits not even hitting the 24" X 36" backstop at 100 yards. I had to lap the dual cavity mold cavities oversize because the as-cast was 0.265" and my two Swedes need 0.267" and 0.268" boolits.

rl 1091

[white eagle]

I have not been doing this as long as most but my thoughts are that bore size and velocity are key
example I would not shoot cast in a 22 cal chambered for the 220 swift \ I would also not consider cast for the 280 ai
I look at the velocity cabailities first, ex.2300-2400 fps then the bore size
anything under 30 cal is not even in the mix
my way may not work for you ,but it works for me though

[runfiverun]

the 22's are wonderful calibers with cast.
the 250 and the swift are almost a pefect match for lead, slower twist rates, enough case capacity to keep pressures low, the rifles are usually target/varmint types, and did i mention the twist rates.
of course this helps with other calibers too.

[DrCaveman]

Another surprising one that works pretty well in some guns is 7.62x39.

Some factors that surely help are the low pressures & velocities of this cartridge. I am loading in a bolt action, not sure of the twist rate. Also I am using a 160 gr cast tip, heavier than the cartridge was designed for. This may help its flexibility.

I am still fine tuning the load for accuracy, but imr4227 seems like the best I've found. Maybe the pairing of certain calibers with certain powders helps with being 'cast friendly'.

Just thought I'd throw this one in, since it has a short neck and is not an American cartridge.

[RevGeo]

To me 'cast bullet friendly cartridges' are the ones that fit the guns I own.
I have yet to find a cartridge that I wouldn't use with a cast bullet.

[303Guy]

I would imagine the 30-40 Krag to an ideal cast cartridge. The long neck, is my reason for thinking that. I'm sure the capacity it optimum for a 30 bore. I've long thought the 30-30 would be the ideal cast cartridge because of its long neck and smaller case, just right for cast boolit velocity velocities.

If I had the means and opportunity I would modify one of my Brits for cast/patched by moving the shoulder back to give a longer neck. (I'd give it a shallow shoulder angle).

[runfiverun]

neck the krag up to 32 or 35 caliber and it becomes something else again.
it will sling a 200 gr boolit at near 2400 fps with no problems.
something a couple of your bbl's would be a candidate for 303.

[Mk42gunner]

What makes a caliber (or cartridge) cast friendly?

In pistols, (or handguns, revolvers or whatever you want to call them) I think it is a combination of barrel twist, nominal pressure for the cartridge and case capacity. For example the 9mm, .40 S&W and the .357, .41 and .44 Magnums all run at close to the same pressure, but the revovler cartidges are thought to be naturals for lead, while the bottom feeders aren't. The main differences are 1. case capacity, the revolvers let you use a slower powder for a gentler initial push on the boolit. and 2. Twist rate, the slower twist had got to be gentler on the softer cast boolit than a quicker twist.

In rifles-- I think that the moderate cartridges that are generally labelled "brush cartridges" are more likely to be considered cast friendly than the longrange cartridges. The .30-30 and .35 Remington pretty much bracket the magnum revolvers, pressure wise anyway. These and the .30-40 and .45-70 allow pretty much factory equivelent (or better) loads with boolits.

It is one thing to talk about how you are shooting a load that is more powerful thna the typical factory load with your own boolits in say the .30-30, it is quite another to say "yeah, I'm shooting a .30-30 level load out of my '06."

Shootability has to play a big part also, it isn't that hard to shoot a hundred trapdoor level loads in an afternoon of plinking, it is quite another to shoot them at Ruger No 1 level. That extra 500 fps makes a big difference in felt recoil on a ~400 grain boolit.

Robert

[MT Gianni]

I think in a rifle that the throat shape, twist rate, cartridge neck length and powder capacity all have a lot to do with it.
The throat should allow even entrance of the boolit without malforming it in any direction.
The twist rate should let you shoot various boolit lengths without overspinning it. There should be no more than .0005" restriction and a slight taper to the muzzle would be ideal.
The cartridge neck should allow you to seat the gc in it and be long enough to ensure that the boolit stays centered as it is chambered and fired.
The powder capacity should allow for a powder that burns evenly without a flashover or the need for more than minimal filler.

In a pistol the requirements are much the same with the inclusion of a feed ramp that does not deform a chambering round.
' Revolvers must be free of bbl constrictions, have a good alignment and a quick lock time. I believe that the pistol manufacture methods are as important as the cartridges. The internals should be free of burrs, guns should have a quick, short hammer fall and fit the shooters hand.

[MikeS]

While I know that 45ACP is a very cast friendly caliber, and 9mm & 40S&W, not so much, but I wonder if 41AE would be more cast friendly than the previous 2?

I just got a Tanfoglio GT41 in 41AE, and while I know I can get a 9mm barrel for it, I'm really not a fan of the 9mm, and would prefer to stay with the original 41AE chambering. While cases are expensive (I just paid $1.04 each for 50 of them), I just think the 41 is a better cartridge for self defense use than the 9mm. I also just bought a Saeco #416 170gr SWC mould for the 41AE (it's specifically listed as being for the 41AE), so all I need now is a set of dies, and I'll be all set to reload it, so I guess I'm going to find out just how hard it is to reload for it. Oh, I'll need a sizing die as well. I slugged the bore, and it's .4095 - .410 so I'll order a .411 sizing die, and call it close enough.

[ku4hx]

I think all guns are cast friendly in much the same way as all trucks are butt friendly. I can sit in any truck and drive it but some are a 10 ... best fit; no back pain. Some are a 5. I can make the 5s work acceptably well but after some time my back hurts.

On a scale of 1 to 10 with 10 being the very best fit, my three 45 ACP guns are all a 9+, my 10mm guns are 8-9. my 9x19 guns are oh a 6-8, 38 Special is a 9+, 357 Magnum is a 8-9 and so forth. But these are results I'm willing to accept here in my "golden years". Could I raise my 6s, 7s and 8s to 9s or better? Yeah, probably but I no longer wish to do that. Now days I do the loading, shooting and cleaning and tend to spend less time on perfecting and more time on shooting. And other stuff since wifey is retired too.

[HangFireW8]

Then take the .30-'06 Springfield, a much-beloved cast boolit cartridge, and study it a minute. WHY? Ok, long neck, mass availability of components and guns, but what else? I find it ok for cast, but most of the time it's loaded to .30-30 levels at best. Is that achieving the best efficiency? I hardly think so.

I don't think the popularity of the 30/06 has been addressed, so I'll speak to that. I think the reasons are the opposite of the .303, which suffered irregular bore sizes. Since the 30/06 was the premier high pressure cartridge for the first half of the twentieth century, American gun makers either got it in every detail right in expensive rifles (Remington 30, Winchester 54 & 70), got it wrong and quickly discontinued it (Winchester 95), or didn't touch it at all.

The high pressure nature of the cartridge demanded that rifle makers get it right or just stay away! This ruled out weaker actions, weaker materials, and all the slipshod manufacturing that went with them.

As a result, almost our entire supply of 30/06 rifles have very uniform bores of .3080 +/- .0005". That, plus all the other things you mentioned, makes for a very cast-friendly rifle, since a beginner can purchase almost any mold and a .309" sizer and be good to go, without even realizing they might have to slug the bore.

I've been thinking about this because I slugged the bore on my (previously inaccurate) FN Model 50, and lo and behold, it has a .3100" bore (and .3000 lands). I was in total shock. (Yes I did it a second time just to make sure). Once I started loading cast to that size, though, I started getting accuracy I never got with j-words! Why? Despite having a non-standard bore diameter, it still had a high quality, consistent bore diameter.


So what is it that makes a cartridge "best"? Is it low pressure limits of the cartridge that keep things inherently in the "cast friendly" pressure range? Is it particular attributes of the case design itself? Tooling specs? Is it the guns commonly chambered for it? Is it nostalgia, or history, or the fact that a given round was touted by famous people? I think it all comes into play, but the bottom line is that the aggregate experience of generations of cast boolit shooters arrive at the same conclusions over and over, and there has to be a "best" reason for their opinions. I have mine, I'd like to hear yours.

I'll throw a monkey wrench in the works- Lyman 3rd edition mentions the 7mm Sharpe & Harte as an excellent cast boolit cartridge! A 7mm belted magnum is not exactly what you think of when you think cast boolit cartridges! (Which makes me want one even more.)

I'll try to list my reasons for popularity in order or priority
1. Uniformity of bore diameter
2. Suitability of rifling (land height, twist rate)
3. Bore ratio
4. Culture, history, availability, etc.

Of these, the 30/06 has everything except the second half of 2, twist rate, but even there it is "close enough", though certainly not "best".

HF

[btroj]

The tough part is differentiating between a cast friendly cartridge and a cast friendly gun.
I think many good cast cartridges also come in good cast guns. These guns have cast friendly throats, rifling types and rates, etc.

I personally think that if you are willing to stay below 2K fps about any rifle can be made to shoot cast well enough to be acceptable.

I also think we have some calibers tha have many more good moulds than others so those are easier to get shooting well. Not many 6 mm moulds out there yet we re hurried in 30 cal moulds. This is a situation where historical favorites have a huge advantage.

[DrB]

I think you also need to consider the throat geometry.

[Lizard333]

What about the sheer volume of information available on any given cartridge. Looking at the " easy" ones, 45 ACP for instance, there is a huge amount of info. It is much easier to find info that is tried and true. The obscure calibers, you have less people casting for them, hence less information available.

[geargnasher]

Lizard, that may be more of a result of popularity, rather than a cause of it. One of the best cast boolit calibers on the planet is the .38/55, but you won't find quite the mountains of data for it that you will for others because, I believe, high-pressure, modern cartridges designed for copper bullets have long ago overshadowed it. Most of the old black powder cartridges couldn't handle anything but lead boolits, and smokeless propellant and "modern" bullets pushed most of them into extinction. Even the venerable .30-30 would be history if it weren't for copper jacketed bullets.

Decent published pressure-barrel data is sketchy on the .35 Remington, too, as I discovered recently.

Gear

[geargnasher]

The tough part is differentiating between a cast friendly cartridge and a cast friendly gun.
I think many good cast cartridges also come in good cast guns. These guns have cast friendly throats, rifling types and rates, etc.

I personally think that if you are willing to stay below 2K fps about any rifle can be made to shoot cast well enough to be acceptable.

I also think we have some calibers tha have many more good moulds than others so those are easier to get shooting well. Not many 6 mm moulds out there yet we re hurried in 30 cal moulds. This is a situation where historical favorites have a huge advantage.

You've brought up some excellent points here, and in your previous post. The subject does get a little murky between effects of gun and cartridge. I'm beginning to lean toward the gun being most of it, because we've proven you can get the same MOA or less accuracy out of a .300 Winchester Mag as a .30-30 (provided you have a gun capable of that level of accuracy), so we handloaders can work around less-than-ideal case capacities, and can make just about anything shoot given a suitable enough gun.

Realistically, you can't make a sewer pipe shoot, and you can't make a .243 into a 600-yard chuck destroyer with cast boolits, but it looks like the way the chips fall with the platform, like Hangfire so eloquently explained above, probably has more to do with the popularity of a given cartridge for cast boolit shooting than anything.

Gear

[Harter66]

I think it has to do w/availibility and cost,in popularity. Even here in in a decidedly not 30-30 class hunting region they're everywhere, along w/38s and all the straight case cousins. In truth I can't say personnally that vintage of design have an effect but I think it helps to start off intended for cast. My 32 Rem ,think AI'd 32 Win spcl rimless,dialed right in, after the learning curve and getting all of the copper out. It shoots as well,faster,more repeatably than any of the other rifles w/less fussyness.

For simpicity I will say OM design w/cast in mind and/or throat/leade shape as the primary handshake . To giv an example (no personal knowledge or research here) for cast freindly how does a 450 Marlin compare to the same 336 in 45-70 ? They should be red apples but I bet they're pears an grapes.