Hard cast vs Jacketed Loads

[Poconolg]

Am I correct in using loads for jacketed bullets reduced 5% for hard cast?

[Nick_C_S]

It's not that simple.

What do you plan on loading? Caliber, bullet, powder, etc. What is your purpose? Target, range practice, self defense, high recoil practice, etc.

What concern do you have that prompts you to believe in a 5% reduction?

[g.willikers]

Yeah, the load data is powder and bullet specific for a reason.
Use only the data for the exact powder you are using, with the bullet you are using, with the recommended bullet depth in the case.
Getting creative with reloading is for the experts.

[T. O'Heir]

The load data is powder and bullet weight and material specific for a reason. You can't drive any cast bullet as fast as a jacketed. Cast bullets usually use different powders than jacketed too. So no you are not right.

[condor bravo]

Probably most everone's "default" in reloading questions like the OP's pertain to handgun loading, but if rifle, that should be indicated (as well as handgun), since responses between the two will vary considerably. But for now the responders are assuming, no doubt correctly, you are referring to handgun loading rather than to use of cast bullets with rifle caliber loads. Using reduced cast bullet rifle loads, especially for some indoor shooting however, can be very practical from reduced expense and prolonging barrel life points of view. I realize this has gone off on somewhat of a tangent but posters really need to be specific and furnish details relative to what they are asking.

[DaleA]

Getting creative with reloading is for the experts.

Or for folk interested in getting a nick-name of 'Lefty'.

Not to continue to dump on the op but if you don't have one, one of the reloading manuals would serve you well with both cast and jacketed information.

http://www.amazon.com/SPEER-Reloadin...ding+manual+15

http://www.amazon.com/Lyman-49th-Edi...3KEN7EPPT93TSV

http://www.amazon.com/Hornady-Editio...25BPPTN7JK3V3A

[ligonierbill]

I surely agree it's not that simple, but let me share some real world examples.
.45 Colt Ruger Blackhawk 7 1/2" bbl:

300 Hornady XTP
22.0 gr H110
1,216 fps avg.

325 Cast Performance
23.0 gr H110 (1 gr below Hodgdon max)
1,346 avg.

Hardcast generally has less friction than jacketed, therefore a little more velocity. But you had best work up slowly for loads like this, and never without some published test data. What are you working on? Give us some specifics, and we'll give specific advice, or even better, real world results.

[black mamba]

With handguns, cast bullets generally give less pressure and more velocity than jacketed bullets of the same weight (ligonierbill shows a good example above). Cast bullets in rifles need to be kept down to around 2300 fps even with gas checks. I have no idea where the 5% thing came from, as each cartridge is a loading problem of its own.

[Nick_C_S]

cast bullets generally give less pressure and more velocity than jacketed bullets of the same weight

Exactly. And to give more detail, lead has less friction going down the barrel of a gun than copper. So all things being equal, a lead slug is going to propel easier, and thus, faster down the barrel. Since the bullet is escaping with more ease, there is generally less pressure.

Important rudimentary fact that every loader should know as general knowledge.

[Sheikyourbootie]

ligonierbill, your load for the cast performance boolit is the same powder charge and same velocity as my 325 grain hot rod setup out of the Bisley Blackhawk. My most accurate load is a mild load of 13 grains of HS-6 with the same 325 grain boolit at 1120 fps.

[ligonierbill]

Thanks, I am mostly loading 255's at less than warp speed. Those hot loads always bust my knuckle. I am working some Cast Performance 360's, so stand by for a new thread.

[TimSr]

You can't drive any cast bullet as fast as a jacketed.

I can.

[DAVID NANCARROW]

A cast bullet should develop more pressure than a jacketed bullet because it forms to the bore more efficiently than a jacketed bullet. However, it does give less friction than a jacketed bullet. That, and a cast bullet is generally sized larger than a jacketed bullet.

[GyMac]

A cast bullet should develop more pressure than a jacketed bullet because it forms to the bore more efficiently than a jacketed bullet. However, it does give less friction than a jacketed bullet. That, and a cast bullet is generally sized larger than a jacketed bullet.

If a cast bullet gives less friction than a jacketed bullet, doesn't that equal less pressure?

[TimSr]

You can think about whatever theory you want, but I handgun hunt with Hornday jacketed XTP bullets. I duplicate them with cast SWC bullets of the same weight for target practice. Whether it be 240gr .44 Mag, or 158gr .357, with identical loads, the cast bullets are always faster.

[Bongo Boy]

If a cast bullet gives less friction than a jacketed bullet, doesn't that equal less pressure?

Yes, if less friction was the only difference in the two 'systems'. What's being suggested is that, while there is less friction, there is also generally a better seal due to cast lead upsetting into the bore more completely than a jacketed bullet can. I'm not arguing one way or the other about what does or does not happen, but the explanation does make sense, at least the way I understand it.

The one single factor that, IMO, makes it almost impossible to use 'common sense' or 'intuition' to explain actual results is that burn rate and pressure both depend on burn rate and pressure. Combine that with the liklihood that the static friction of each bullet type--the amount of pressure it takes to get the bullet moving in the first place--is likely also different between the two, and so that impacts the peak chamber pressure, presumably.

I wouldn't expect a better-sealing bullet to make as much of a dent in the efficiency of a revolver though, in terms of percentage increase in MV. Sort of like trying to keep boat afloat that has a 2" hole and 1/4" hole in the hull, and you plug the 1/4" hole and expect things to improve. Again, intuition doesn't save the day here.

Anyway, rather than speculate and use intuition, this seems like a case where actual experience serves best. In an earlier post, identical loads with identical weight bullets from the same firearm produced what I think was at least a 10% increase in muzzle velocity. I know I generally end up using identical charges for both cast and jacketed, but have never intentionally done a side-by-side comparison. In tens of 1000s of rounds shot in handgun, I've never seen any significant issues with pushing cast just as hard as jacketed--the oft-cited threshold of 1,000 fps or so is pretty much pure nonsense.

[black mamba]

I pulled some loads from the most recent online load data from Ramshot. Comparing loads of 44 mag with two different pairs of bullets, lead and jacketed. In both examples, the lead bullet developed more velocity with less pressure using more powder.



Counter-intuitively, bullet diameter has very little effect on pressure. P.O. Ackley did some tests decades ago loading the next full caliber larger into cartridges and firing them (e.g.: .284 bullets in a 270 Win). You would think they'd blow up the rifle, but the effects were negligible.

[DAVID NANCARROW]

The problem for some of us...at least for me, is that I have no scientific way of actually measuring the pressure, so its sort of a spitball theory

[hartcreek]

The correct answer is it depends on the specific loading for handgun or rifle and the individuals expertise at casting and reloading.

I hardcast and I am shooting gaschecked 160 grain bullets out of my 1956 Remington 721 in 30-06 at 2500 fps with no leading. I also handgun hunt with a .44 magnum and use Hornady XTP hollow points for SD and my 240 grain hard casts for practice and hunting with no leading. I use 22.7 grains of 296.

[Handloader109]

I think you cannot really state a hard and fast rule. Way too many variables. Several that you miss, and sorry, if you are assuming identical, you would be wrong as each bullet is shaped different. Oal was never mentioned, this plays big factor. Just looking up Lyman manual 49th version for my 9mm, same bullet weight, two different powders give alternative results, velocity is fairly consistent, cast is faster, but pressure can be high for one powder and lower for different. Max and min powder volumes can be same or vary, different results... Don't make blanket statements, use published data, and vary at your own risk.....and published is not what you find in forums. Be very careful in using that....

[gwpercle]

A straight up 5% reduction from jacketed to cast is not going to work in all instances, things like this never do, just too many variables .

This 5% reduction might be more applicable for plated bullets, they aren't as hard as jacketed but are harder than cast .

If you wish to load cast, use cast bullet data....Lyman Cast Bullet Handbook is a wealth of information, even listing pressures of loads.
I have both the #3 and newer #4 editions and find them invaluable, highly recommend you get one.

Gary

[Crusty Deary Ol'Coot]

Poconolg,

You give far too little information for us to give good answers that may apply to your need.

However, as said earlier by a poster that cast bullets can not be driven to the velocities of jacketed bullets, I'll have to say, That Depends!

Frankly to develop high quality cast bullet loads it is very likely to take much more load development when compared to "J" bullets.

The simple reason it the much higher level of variables.

However, from my RUGER #1 - 45/70 I have done a bunch of testing with loads of over 2000fps, testing as high as just over 2500fps and hunting with a 355gr Wide Flat Nose cast at 2300fps.

It is not uncommon for some cast bullet shooters to exceed those velocities.

I have found a 465gr Cast WFN at 1650fps to be MUCH better in the end result area, but am currently in the process of testing IMR 4895 with this bullet and should I see much improved groups over my current load or H335, I will possibly end up with a load in the 1700 - 1800fps range.

Typically a cast bullet develops less pressures the a "J" bullet of equal weight, but as has been suggested, get some information from a good source before you make a serious mistake. Lyman is one good source for such info.

Crusty Deary Ol'Coot

[pete2]

Poco,
Invest in Lyman's pistol and revolver reloading manual, it covers cast and jacketed bullets. Lots of loads and lots of info that may be helpful to you.