Rookie Question

[JohnResch]

Greetings, I am new here. I have been reloading for years , you know back when it was easy to get components. So as necessity is a mother I am venturing into the world of casting bullets. How hard could that be! Giant learning curve. Which bring me to my question. Having sourced some raw material and playing with mixing some alloys and playing with my new Lee hardness testing kit I can achieve certain BHN number. But my real question is about gas checks. So if my BHN is say 18 but i am putting these bullets through a .30 cal rifle it would appear they should be harder to withstand the high pressures. But if I put a copper gas check on the bullet do I need all that hardness or does the check cover that issue.

Thank you in advance for tolerating the rookie long winded question.

Regards.

[Winger Ed.]

Check out the Lyman manual.
It lists all its data with Lyman #2 alloy, and they tell ya what it is too.

I don't have a tester, so I sort of approximate my alloy, and have had good luck with that.
I load .30-06 and .308 with cast 170RN and 190SP & 3031 or 4198
to right up around full house .30-30 speeds for 100 yard or so hunting.
I use 'the load' of Red Dot to get them in the mid-teens for target shooting.

One of the big things a gas check does is keep the powder flame from vaporizing some Lead at the back end of the boolit.
The melted/vaporized Lead sort of condenses in the bore and contributes to the leading effect.

[Bazoo]

I use wheel weights + tin for full power 30-30 loads, using a 31141 with 28 grains 3031 and 32 grains w748. I ain't tested them but they are something like 12 BHN I hear. Sizing .310 with 50/50 lube.

No cast bullets do much better than 30-30 to 30-40krag ballistics without extensive skill, experience, and experimentation. Hard bullets are needed if you're pushing the envelope but no more than ww alloy is needed for 30-30 pressures.

Post script, welcome to the forum.

[wmitty]

Welcome to the forum! In trying to answer your question, it seems you have a pretty good grasp of alloy hardness and gas checks being used to allow higher velocity with a moderately hard alloy. Have you decided which boolit design suits your needs? If you would give us specific info (cartridge/ boolit/desired velocity/ hunting or target use, etc) it’ll be lot’s easier for us to answer in more detail.

[popper]

What cartridge? What rifle?

[charlie b]

And how fast do you expect to push the bullets? Short answer is yes, the alloy matters, even with gas checks. Lube matters too.

[JohnResch]

Thanks your your interest. The mold I am using is a RCBS 30-180-FN. started out working up some loads for a friends 30-30. Tricky to find good data for a bullet that heavy for a 30-30 but we an work within. They Actually come out of the mold closer to 190. They are of course stepped to accept a GC. I have a good source of " lead " which is wheel weight raw material thAt has never been cast into weights. 60 pound blocks that go into a smelting furnace to be cast into wheel weights. They test on my Lee hardness tester at 14.9 BHN air cooled. Working with some odds and ends I have I have been able to get a few pounds of material up to 18.6 BHN (water quenching). I see no reason why these would not work in any of my .30 cal guns? But I need to understand if the gas checks solve the issue of getting the alloy much harder than it is. I have sourced both copper and aluminum gas checks and in testing they get very happy when run through a .309 sizing die. Any advice is welcome.
Thanks

[Conditor22]

These are maximum loads, start 10-20% below this and work your way up




from cast pics load data--- https://docs.google.com/spreadsheets...gid=1220600477

[charlie b]

This is all kind of general info. Each barrel will like different bullets, bullet dia and velocities.

Gas checks work well. If the bullet is made for them then the gain in accuracy is worth using them. If you keep vel in the 1500fps range or lower then you do not have to use a gas check design.

Alloy is depending on velocity. I use Lyman #2 which is around 18bhn in my .308Win. Velocities from 1700 to 2000fps. I have driven them to 2200fps. Lube makes a big difference at higher velocities, as does rifling twist. Lower velocities you can use softer alloy.

The .30-30 is a good place to start as the velocities are not that high and it has a nice long neck.

I'd recommend you get a copy of the Lyman Cast Bullet handbook. It has a wealth of information, even if it does not include a lot of more recent powders.

[quilbilly]

Welcome to our group. The art and science of shooting CB's in modern rifles adds several new variables to shooting that brings whole new challenges to reloading. It is very addictive as you will find out.
It has been my experience that when you use gas checks, you don't need nearly as hard an alloy for your bottleneck calibers. The alloy I make is about 65% pure and 35% hard, chilled bird shot for my 30's and several other rifle calibers. This moderately hard alloy gives terminally excellent weight retention, expansion, and penetration, as well as fine accuracy. The gas check allows you to increase velocities to over 2000 fps from the plain base maximum of about 1350 fps. Most of my accuracy has been found between 1700 and 2000 fps which has worked well for hunting deer type game at distances under 200 yards for the 30's. This same alloy also shoots very well in my handguns with plain base boolits.

[quilbilly]

Welcome to our group. The art and science of shooting CB's in modern rifles adds several new variables to shooting that brings whole new challenges to reloading. It is very addictive as you will find out.
It has been my experience that when you use gas checks, you don't need nearly as hard an alloy for your bottleneck calibers. The alloy I make is about 65% pure and 35% hard, chilled bird shot for my 30's and several other rifle calibers. This moderately hard alloy gives terminally excellent weight retention, expansion, and penetration, as well as fine accuracy. The gas check allows you to increase velocities to over 2000 fps from the plain base maximum of about 1350 fps. Most of my accuracy has been found between 1700 and 2000 fps which has worked well for hunting deer type game at distances under 200 yards for the 30's. This same alloy also shoots very well in my handguns with plain base boolits.
For the record, I don't have a hardness tester. I just used trial and error to find what has been right for my purpose.

[Land Owner]

So many answers to to-few questions Grasshopper. Remember, before BHN was even, you know, a "thing", our ancestors were killing one another, taming the West, and attempting to eliminate the Plain's Buffalo with lead boolits (mostly pure lead) of unremarkable hardness, less than maximum velocity, dirty powder, in inaccurate, unrifled (and later rifled) barrels.

I will not stand in front of a soft (say 8) to medium hard (say 13) alloy 30-30 boolit, of medium weight (or heavy) for caliber, with a large frontal meplat (whether aerodynamic or not), over a suitable modern smokeless powder whether or not the shooter can accurately put that boolits in the right place. We send "ash cans", flat ended cylinders, down range accurately, at increasing velocities, with regularity, AND most importantly with killing force.

It isn't alloy hardness doing the job - it is impact, alloy malleability, distribution of force, disruption of the pathways for the flow of electrons, holes in vital organs, and a variety of flesh and bone "chemistry" (shock) that kills. A 6 BHN lead boolit can smack the life out of man and beast as can a harder (it's all relative) 18 BHN alloy.

What is your desired USE for your 30-30? Home defense? Deer, Cariboo, hogs? Rock and aluminum can killer? Hardness is not the Tale of the Tape here.