What's wrong with this picture/cast bullet. Or what were you thinking?

[dellet]

[Dolomite_Supafly]

At what stage is that bullet.
Just cast, during coating or after firing?

If that is just cast, your mold is not hot enough and possibly the pour itself. I'll wait on your answer before writing a book.

If that is during coating turn the temp down or get the bullets farther from the heating elements.

[Dolomite_Supafly]

Ahh fuck, didn't realise that was you before posting.

That is a bullet from your caster.

[dellet]

Sent for testing.

it was powder coated

Better pic, it's once fired

[GunFunZS]

Those bullets passed the hammer test, and I fired probably a hundred or two out of a couple guns neither of which had leading.

I mailed most of that batch out to other people, and haven't heard back from them.

I wonder if your leade is just sharp and shearing off the coating, or what? What brand of barrel is it?

You mention pressure, which I suppose makes sense, since the bullet would obturate harder into the bore, and therefore have more friction.

I'm also curious what your method is for catching them. Mine when I can is to find a sandy spot in the berm and put specific targets in front, so I know which bullets came from which lot as I dig up the berm a little. Usually I will find a couple per every 10 or so. Haven't had a good place to do that for a while.

[dellet]

Kind of a trick question, nothing really wrong with the bullet except the guy loading it. What you can’t see in the photo is diameter, it’s 2.995”. You can see a bit of rifling but when you compare it to the others below it starts to make sense. The bullet in the original photo was pushed too hard and too fast causing it to drive straight across the rifling. Velocity and pressures are noted. But the bullet in question was over 2300fps and 55,000psi. It never had a chance and I suspected that when I loaded it.

That bullet probably has 18-20 BHN, hardness number, the bag was marked 17, but they have sat for a year and should be a bit harder now. If that is the case and depending on whose chart you believe the should be good to just over 2000 fps and maybe as high as 45,000psi.

All these were shot in a 10” barrel and captured in gel. Next step is shoot the 1900 fps load in a 16” barrel and see how it does a bit faster and keeping the pressure the same.

We will probably revive the original thread or link it here. Gunfunzs sent me these and I just needed some good time to find the upper limits of the bullet before getting serious. These weigh in at 125 grains and were made from a mold that was cut down. I was very surprised that a three shot group of the stripped bullets was only about 2” at 50 yards and the holes were actually round.

Good example of matching lead hardness with powder choice.

[GunFunZS]

While you have certainly had more experience, and better documentation and the ability to measure and test more variables, so far I've gotten good accuracy wherever Richard Lee's pressure charts predict that I should, and bad too.

I'm not a blind follower, and I am all for more data and testing everything, but that's been a good starting point for me.

[GunFunZS]

I still want to know how you are catching the bullets so cleanly. Do you have a big box of fluff or a bunch of polarfleece?

[dellet]

While you have certainly had more experience, and better documentation and the ability to measure and test more variables, so far I've gotten good accuracy wherever Richard Lee's pressure charts predict that I should, and bad too.

I'm not a blind follower, and I am all for more data and testing everything, but that's been a good starting point for me.

Probably wasn’t as clear about trusting the charts. I don’t have an accurate way to test hardness or pressure. So in All honesty the charts are probably not the issue, it’s the guy inputting bad information. Quickload is a big help, but has its limits.

One thing I can say is that starting pressure and how fast you get to peak pressure is also a factor. Fracturing style bullets can fracture in the barrel if they start too fast. I have had some come apart at lower velocities and equal peak pressures using faster powders. I think it has to do with how fast they accelerate.

A 125 grain bullet at 2300 fps in a 10” barrel is being pushed pretty hard and now that I have a known failure point I can work out if it’s pressure/time or straight velocity.

I am catching those in 10% ballistic gel. They impacted within 100 fps of the velocities noted and had about 24-28” penetration. It really helps for stuff like this.

There is so much more to making cast work well, and I’m at a place where I might actually be able to get some shooting right, I hope. I think I almost know all the right questions to ask, now to find the answers.

[GunFunZS]

Thanks very much.

I would really love to see pictures of what the gel looks like, even if it isn't calibrated or lit perfectly.