Hard cast at higher velocities.

[slammedsi]

I'm looking at loading lead hard cast .452 of the RNFP type for my 460 Rowland. I'm wondering if I can push a hard cast with out gas checks to the 1300-1550 fps range without problems. Correct me if I'm wrong but doesn't a lead bullet require a gas check for these types of velocities to prevent heavy leading of the barrel?

[andyjr11]

I run hard cast lead in my 357 and 44 mag at over 1500 and have had no problem at all. The gas checks are for the soft lead and are usually run slower any way, like in cowboy loads.

[zxcvbob]

It depends on bullet fit, the alloy, and how smooth the barrel is -- and probably a few other things. I have pushed plain based cast bullets at just over 1700 fps in a Ruger Blackhawk .30 Carbine with no leading at all. And I don't know why.

My other Blackhawks (.41 Mag and .45 Colt) lead a little at 1200 to 1300, but not bad. I also use cast bullets at about 1100 or so in several semiautos w/o leading. My Taurus Gaucho leads badly with lead bullets at any velocity... OTOH it is a Taurus.

It's probably easier in a semiauto because you don't have the potential problem of the cylinder throats being too tight for the barrel, or binding where the barrel screws into the frame.

[snuffy]

So, what is this hard-cast thing?

That's a term that has been bantyied about for a long time with no real definition. It could mean any bullet harder than pure lead.

Whether any bullet can be pushed that hard without leading is a big question. As zxcvbob said, it has everything to do with whether the fit of the bullet is right on to the bore of the barrel, and the throats of the cylinder.

[oldpapps]

"I'm wondering if I can push a hard cast with out gas checks to the 1300-1550 fps range without problems."

Simple answer, YES.

"Correct me if I'm wrong but doesn't a lead bullet require a gas check for these types of velocities to prevent heavy leading of the barrel?"

Simple answer, NO.

Not so simple answers.

The interior of a barrel 'leads' because of several factors. Pushing the bullet too fast or too tight of twist or too soft/malleable of bullet surface material and others.

I have found that bullet to barrel fit is the biggest problem. If the bullet bounces down the barrel, all is not well. Conversely, if the bullet is massively over sized, we've got problems. For soft bullet material (lead) about .002 over size seams to work well. Harder/jacketed bullets that may be too much.

The bullet should seal the barrel to gasses. The base/butt of the bullets will need to be pushed into the body of the bullet to cause 'it' to swell and seal the barrel (this is called obturate). If the barrel isn't sealed hot gasses will burn down the side of the bullets and leading will occur.

For lead bullets, the bullet alloy can take the 'hardness' from dead soft to very hard. Add to this the rate that the lead cools will affect the hardness also. Rapid cooling makes larger lead crystal structures and the effect is harder lead. Slow cooling and smaller crystals are formed. Don't worry, over time the size of the crystals will even out.

Now we come to the 'gas check'. One view is that it protects the butt of the bullet from hot gases. Another is it scrapes the lead off. I don't know. But I do know that they do work.

Summing up.
If an alloy is selected that produces a harder lead (to know, a tester is needed) and the bullets is cast to very close to the end desired diameter (working the lead breaks down the crystals with the effect of making the surface softer) and is lubed (this has it's own science) properly, a 'gas check' is not needed for the listed velocities and beyond.

Side note. Some say that a gas checked bullet with out the gas check looses accuracy. I personnel have never tested for this. But if this is correct, what about my bevel based bullets and all of those boat tailed bullets? It could be that the butt of the gas checked bullet with out the gas check isn't as flat/level/concentric?

I most likely only irritated some and I'm sure some of my views are incorrect and I will be told so. But, this is how I see it. I cast my first bullets in 1963 and they worked for me then. So I can be all wrong.

Enjoy, for that is what it is all about.

OSOK

[mikld]

A while back "hard cast" meant any cast bullet to differentiate cast from swaged. Today most new lead bullet shooters think harder is better and commercial casters have taken advantage of that and now sell "hard cast" bullets, sometimes up to 21-22 BHN (I haven't heard anybody selling "soft cast" or plain old "cast" bullets!). I have gone to magnum velocities, 1200, mebbe 1400+ fps with air cooled wheel weight alloy, plain based bullets. The deciding factor is bullet fit. Any bullet that is too small, no matter how hard it is will lead the bore. You'd have to slug the bore (and cylinder throats?) and size accordingly. A good source of cast bullet info is Lyman's Cast Bullet Handbook (if you can find one get the 3rd Edition, much better for new casters).

I don't use gas checks in my handguns anymore. I have a mold for a .44 cal. 250 gr. bullet with gas check, but I rarely use it as I'm doing fine with plain based bullets (but I'm not familiar with 460 Rowland). Most leading occurs when the bullet is too small, and doesn't obiturate (bump up) and hot gases leak around the base and melt the sides and depositing lead. A proper fitting bullet seals the bore and softer bullets will bump up and also seal the bore...

[slammedsi]

The reason I've asked is I wanted to use a 250 grain bullet which are normally sized .452 unlike your normal 185 to 230 grain bullets that are .451, and then push said 250gr slug at 1200fps.

[oldpapps]

slammedsi,

I would think what your are wanting is do-a-ble. It will depend upon your barrel and the forcing cone. The .452 is normal for lead.

Start with a known safe loading and slowly work up to your desired recoil point, checking for all pressure signs and leading at each step.

Load with care,

OSOK

[tangolima]

I was about to post something similar and I saw this thread.

I have been using cast bullets for pistols and get quite comfortable with them. Now I am going to load them for rifles. I ordered some .30 cal gas checked hard cast bullets online. I plan to load them in .30-06 and drive them around 2200 fps with bolt gun. Question is whether I can go a bit faster. I only one powder for jacketed bullets. It may not work well for light loads.

Thanks.

-TL

[Unclenick]

I always try to keep in mind the 16:1 lead:tin is the hardest thing Elmer Keith used in developing the .44 Magnum. On the other hand, you look at older guns and they often seem to have a finer finish than modern average, including inside the bore.

The other thing to keep in mind is that velocity numbers are just a way to approximate what's happening to the bullet. It's actually pressure you are concerned about, and a bullet that gets to 1200 fps in a carbine and one that does it in a 4" handgun aren't operating at anywhere near the same peak pressures. This is what Richard Lee was angling at in Modern Reloading; rating alloys by the peak pressure they'll see. But he didn't like any pressure distortion, while gun with bore diameter variations, and particularly revolvers with throats that aren't a thousandth or two over groove diameter and with bullets not over half a thousandth smaller than they are, will be in need of something soft enough to upset (bump up) back out into the bore after passing a tight place.

I was interested to note in the page on firelapping at the LASC site that one contributor found that all he really had to do was polish the bore with a tight fitting patch and Semi-chrome polish. Constrictions remained but the bullets could upset back out to fill them an he got no leading. This matches what Varmint Al does in place of "break-in" on a rifle barrel, except the polishing product choice is a little different. I'm not convinced the exact brand of polish matters a lot.

[skizzums]

i would seriously consider PC if pushing lead though a 30-06

[tangolima]

What's PC, if you don't mind me asking? Thanks.

-TL

[skizzums]

powder coating, look on the bullet casting forum and youll see a bunch of threads on it
http://thefiringline.com/forums/showthread.php?t=542809

http://thefiringline.com/forums/showthread.php?t=536424

[tangolima]

Powder coating, of course. Unfortunately it is not an option for me. I have to buy commercially available bullets. Are powder coated .30 cal available online?

-TL

[skizzums]

Not that I am aware of, but ypu can do an acetone wash on commercially cast boolits, and then powder coat yourself. Extreme bullets sells a plated 762x39 bullet, I am not sure the diameter though. eck the website, cause their bullets are almost as cheap as cast and i have been super pleased with their plated bullets

[tangolima]

Yep, I bought 7.62x39 plated bullets from xtreme for my sks. It has .310" diameter, which is not ideal for .308" bore.

-TL

[skizzums]

it could be, plated bullets have pure lead under them, i would ask around, but i bet 310 would be a great diameter for it, the question is the weight only being 125 or whatever it is

[skizzums]

Actually, they are sized .312 at extreme bullets, but ppl just run them through a sizing die, works well apparently

That's what I plan to use for 300blk

http://www.xtremebullets.com/7-62-s/48049.htm



LOOKY LOOKY!!!!! they sell 308 plated now, thats new 308 diameter too, 150gr
http://www.xtremebullets.com/308-s/48051.htm

[tangolima]

Cool. I'm gonna get some of those for myself. How much over 2000fps can I drive them, I wonder?

-TL

[skizzums]

cant say for sure, just do your own testing, you can pay a few buckks extra to get them double plated, but the single is pretty thick, i would doubt youd have problems, i can give you a cross-section today if youd like, and you can compare to a cross of an actual jacketed

[tangolima]

How do I order double plating? Call them?

-TL

[skizzums]

they offer them on almost all there other calibers, so i think a phone call or e mail would probably get you fixed up,