Gents,

Can someone explain to me why Sierra's manual #14 lists a max load of 7 grains for Unique powder under a 240 grain SWC (.430") while the classic light Taffin load is consistently listed as 8.5 grains Unique under the same weight of SWC?

Is the difference due to bullet hardness? If so, what's the threshold?

I have some 240 grain SWC's (.430") w/ a BH of 10. I'd like to load these over 7.5 grains of Unique for a paper punching & rabbit load, but not sure if that's "too light" or "just right", given their hardness.

I have loaded up some Oregon Trail 240 grain SWCs over 8.5 grains of Unique - they shot very well and recoil was pleasant, but I experienced a little leading downstream of the forcing cone. Given their hardness of ~24 BH I'm thinking that load was a little too light to seal out gas cutting.

Any input is welcome.

Thanks.

I'd start with 9.0 regardless of hardness.



Travis

A lot of it is the shape of the various bullets, those with a longer bearing surface will up the pressures a bit, even if the weight is the same.

+1..... Also the amount of bullet in the case afects case capacity. Cast bullets also tend to be able to use a bit more powder for the same weight and pressure

With non-jacketed bullets, it may also be related to whether the bullet is a relatively soft swaged bullet, or a hard cast bullet. The swaged bullets do much better with lighter loads.

Thanks to all for the info.

TomC321, is a bullet with a Brinell hardness of 10 considered "hard cast"?

If it is, does anyone see any potential issues in loading it on a charge of 7.5 grains Unique? I want to make sure this load isn't unsafe due to too light a charge.

Speer manual 13 lists 7.0 gr Unique, for 899fps, as max with a 240 swc

Fired from 7.5 in Redhawk

I'm trying to remember if I loaded 9 or 9.5 grains under a 240gr cast bullet the last time around. I DO recall that it clocks a bit under 950 fps from my 7.5" Redhawk and 1,100 from my little Marlin 1894P.

A Brinell hardness of 10 is not very hard. I would keep it under 1000fps. I think Lazer Cast bullets have a Brinell hardness of 17 or 19 (I'm going off memory).

In cases such as yours, a chronograph is your friend. With lead bullets, I pick a bullet of same weight and similur shape and use published data. I pick a medium charge of the listed powder. If I get velocities that are close with that test load, I continue to use it.

GB

Some of the manuals treat cast bullets as though they cannot be used "seriously" and are only for powder puff loads. The manuals showing +/- 7 grains of Unique as "max" aren't claiming those loads are maximum pressure, just maximum velocity that probably won't lead too badly no matter how poorly the bullet is matched to the gun/load.

My most used bullets are about 12 Brinell. They work well up to about 1200-1300 FPS - when properly fitted to guns with firelapped barrels. If shot undersized, or "lubed" with the hard wax stuff almost universally used in commercial bullets, or fired in revolvers with thread choke - i.e. most modern big-bore revolvers - then they can lead badly even well below 1000 fps.

"Hard cast" to me means higher than 15 Brinell. By the time you're into the 20s, you have a super hard bullet that, IMO, isn't very useful, as it takes rifle pressures to obdurate a bullet that hard. Such hardness levels have been turned into an advertising point with many manufacturers, with the idea being that "harder is better". The truth is simply that the alloy most commonly used for commercial bullet casting is really hard, but that's a byproduct. The reason that alloy is used is because it casts easily with a low reject rate and makes into nice, shiny bullets that look good to the consumer. A softer alloy would be better for almost every purpose, but is a lot tougher to cast when using automated machinery.

Having said all that, a load of 7 or 7.5 grains Unique is a fine light load (.44 Special factory load level) with a 240 grain cast SWC of 10 Brinell. Upping to 8.5 grains will essentially duplicate the "Skeeter" .44 Special load, and 10 grains gives you the velocity Keith used in his .44 Special hunting loads. All of these are well below maximum pressure, and all but the latter will work fine with 10 Brinell bullets, again assuming the bullets fit properly and carry a goodly portion of high quality lube. The Keith load is probably pushing the soft bullet a little too hard, but by the time you're into 12-14 Brinell, it'll be perfect. And the 20 Brinell bullets will still be too hard...

If you're using a Ruger, .430 is fine, and .431 would probably be better - most modern Ruger .44s have .431 throats. And, if it's a Ruger, any cast bullet load will probably lead just ahead of the forcing cone, because almost all big-bore Ruger revolvers have significant thread choke. So you can either live with it, firelap it, or stick with jacketed.

The Speer bullets are soft - they're not the same as hard cast, and if pushed very hard they'll lead the barrel badly.

Mild charges are appropriate for the soft lead bullets, while the hard cast bullets can be shoved as hard as a jacketed .44 mag bullet.

Regards, Guy

This has been excellent info. Thanks again to all that replied.

Robert Wilson: Yes, this is a Ruger. A Super Blackhawk w/ 7-1/2" barrel. All leading is downstream of the forcing cone, w/ most leading occurring in the first 1". Sounds like firelapping is in my future if I want to continue shooting cast bullets, and I do.

Armen,

I just cut and pasted this info from a previous thread I had replied in. I shoot and reload the .44 quite a bit. Data:

Three main loads:

Light load: 8.5 grains Unique/ 240 or 250 LSWC

Medium load: 10 grains Unique/ 240 or 250 LSWC

Heavy load: 22 grains H110/ 240 or 300-340 LSWC or LBT wide meplat style.

These have served me well for years, all are Smith friendly.In Rugers you can safely bump up the heavy load 2 grains with no concern.


The medium load is my general purpose/all around load. Kills mule deer/pigs, whatever.

MS

I own more .44 Blackhawks (Special and Magnum) than I need to, and all of them have had significant thread choke. And all of them leaded in exactly the way you describe. But all of them have, so far, responded beautifully to firelapping. I'm at the point where I just expect to have to do it when I buy a new big-bore Ruger. Have fun!