I have put this one over on Cast Boolits.

Is there any reason not to cast a bullet with an exposed lead boat tail and a copper or brass driving band just at the boat tail/shank junction?

The idea is to carry the lube on that boat tail!

I too have wondered about cast bullets with a boat tail, is it possible? Sense we shoot most cast a lower valisity then copper jacketed. Why not try to sub-sonic bullets or better for long range work? I m quite shocked there is no boat tail gas check!
I often bounce off the wall ideas in my head and every now and again one or two pop out. So look out.

If the cast bullets are being pushed at a low enough velocity, a gas check isn't needed.
303, I'm still trying to figure out how the lube, on the boat tail, helps your bullet.

the only reason i can think of is that is where all your pressure is located at.
and you will blow all the lube off in the throat area and not push any down the bbl.

quote:

Originally posted by Lamar:
the only reason i can think of is that is where all your pressure is located at.
and you will blow all the lube off in the throat area and not push any down the bbl.

maybe he wants to shoot them backwords

Well, the idea is to blow the lube forward into the bore where it deposits and does its job. I have made the observation that lubed bullets often still carry their lube in the grooves when recovered. So, most of the lube has done nothing. Well, it has in that it has pressed the 'working' bit of lube onto the bore. I have experimented with this principle with jacketed bullets and have found the bore to remain clean and shiny with no sign of copper fouling. I have thought of using a lubed wad under the bullet but two things worry me. Firstly, the bullet gets seated to the base of the neck so the wad could get pushed into the case. To avoid that possibility, the bullet must be carefully seated above the shoulder - in a short necked case with a long heavy bullet. The other concern is that the wad gets stuck onto the base of the bullet and may or may not come off during the bullets flight - at some inconsistant point. When it does come off, what effect will it have on the air flow at the base of the bullet? Besides, just how much lube will actually get to the bore? I was also thinking that lube on the boat tail of a lead bullet might help protect the bullet from flame cutting - with or without the base band or gas check.

Another aspect of lubed bullets I have not mentioned is that my rifles are fitted with non-removeable 'devices' which need to be protected against corrosion and the lube deposits inside these 'devices'. I did notice that there no lube is left inside the bore of the baffle and if not oiled, light rust forms. The muzzle side of the baffle bore is fine.

quote:

... boat tail gas check!

Well now, maybe that is the answer to making our own gas checks? It's quite hard to make a 'normal' gas check but shaping it like a boat tail could be just the ticket! I think I'll try it. Mmmm....

I have been in communication with MR Corbin, and he makes a die to make our own gas checks if you want one. They can be made to any size check 2/3 the way up the bullet I think he said

Thanks for that. Mmmm..... that's interesting!

The problem with casting gas checks in place is that they need to be heated to pevent casting defects and this slows down the casting process dramatically! It is possible to cast a gas check recess into the bullet base with a stepped base plug. But then I would have to use a separate step to seat the gas check. That could be combined with swaging. I'll have to think about that one.

Another consideration regarding the base band is that it would form a transition boundary between the body and the boat tail. This thinking has been confirmed over on Cast Boolits.

303; the problem I see with it is the boat tail will obturate in the throat(or possibly the case neck-depending on powder speed/curve), unsupported and will give you an uneven bullet base. The Wilkes checks work, as you have read in the article posted before, but are a pain to cast inplace. If you are wanting to carry lube on a swaged bullet I would think knerling to be the simplest method, it works for Hornady, Speer, Rem and others. I think you could roll some shallow grooves in also to carry lube. If that doesn't sound appealing to you? moly comes to mind.

quote:

moly comes to mind.

I have seen cast bullets of the conventional design with a blue coating. These work. Is that moly? How do I go about moly coating?

quote:

Originally posted by 303Guy:

quote:

moly comes to mind.

I have seen cast bullets of the conventional design with a blue coating. These work. Is that moly? How do I go about moly coating?

Blue coating? I don't know what that would be, possibly a spray on coating? The moly coating I do is tumble imbedded into the bullets, you can buy a kit from several suppliers, mine came from Cabelas about 15 years ago. There is also some "spray paint" moly, I have not tried this though. I moly coated some cast bullets a few years back, 175 grain for 8mm, but I used conventional lube with them also, was tryoing the moly to see if accuracy changed, it didn't coated and uncoatede shot equally well. If you are set on dip lubeing, Lyman makes stick bullet lube that contains moly. Do a search for LUBRICATION SPECIALISTS, I bought some bullet lube from them a few years back, it was about the consistancy of 20W motor oil, just tumble the bullets and let dry. I was testing it with jacketed bullets in 7mm rem mag and others, it definately reduced pressures with jacketed bullets, may work with your lead bullets, I don't know. It was something like 10.00 per ounce, but an ounce would coat a lot of bullets, probably a thousand. Scot

Thank you!

the blue coating is boron nitride.
303 guy i think you might want to try a long gas check shank and then fill the excess area with lube.
now there are two thoughts on lube here a hard lube so that it stays in the lube grooves all the way to the target keeping the grooves filled and causing less wind disturbance over the body of the boolit.
the other is a soft lube that flows in the bbl better laying down a wet coating in it and to the end of the bbl producing the wet star[a dry/hard lube will leave a star also as will moly]
but the lube then spins off the boolit when it leaves the bbl [hopefully all of it evenly]
i have searched and tried different recipes to find a soft hard lube like the consistency of silly putty almost but stays stable over hot and cold temp swings.

quote:

303 guy i think you might want to try a long gas check shank and then fill the excess area with lube.

I have been thinking adout that. Entirely possible with the mould set up I have! My biggest problem is the gas check itself - 30 cal. I can't seem to find any 32 cal gas checks. If I go gascheck-less then I could use the gas check step to carry the lube which will then be blown off by the propellant. And with luck, prevent flame cutting! Have you ever seen flame cutting on brass? I have! But the bullet stuck in the bore and all the gas had to escape past it.

Where would I get this 'boron nitride'?

I v been popping in and out fallowing this thread. why exactly do you want to put your lube at the bottom of your bullet?

quote:

why exactly do you want to put your lube at the bottom of your bullet?

The idea is that propellant gasses blow the lube forward. A base lubed bullet (one with a lube wad) will hopefully leave a layer of lube in the bore for the next shot plus any gas leakage will carry lube forward with it and with a bit of luck, will prevent flame cutting.

Check this out;

And the other side;

There is a distinct ridge visible which used to be the rifling. There is no sign of flame cutting nor lead smearing even though the bullet is somewhat damaged. This bullet had no gas check and was fired out my two groove barrel with a charge of 23grs AR2208/Varget. There was also a wad of cotton wool over the powder. The bullet had a waxy-lube wad and was lubed with waxy-lube. Pressure in the case was mild but not insignificant. However, the base where the gas-check should have been has deformed somewhat. That's the idea of a boat tail - to preserve the base.

This is what happens without the waxy-lube wad and cotton filler. This one even had a gas-check.

it looks like your bullets have no lube groves. do you think it would help if you were shooting bullets that had lube groves? With my black powder shooting some of my friends will dip there bullets in melted lube or bee's wax. Maybe all you need to do is add a touch of lube to your bullets before shooting to lower friction and its adverse affects?
Hope this helps!

quote:

With my black powder shooting some of my friends will dip there bullets in melted lube or bee's wax.

That's what I do too - after seating.

Remember this pic?

That black goop on the bullet is waxy-lube, which simply a mix of wax, alox and STP.

have you tried before?

I posted the wrong pic there - sorry 'bout that! (Trouble with the computer running slow - had to reboot).

OK, so the right pic is now in place. That's how I lube my cast bullets.

This is the result.

quote:

have you tried before?

Oh yes. I'm now trying to do without the gas-check. From the last test I did today, it seems there is no chance. The gas-check is needed to hold the bullet base together during firing. If you look closely you can see the base deformation. No way that will ever shoot straight! Not with those pressures anyway. So, gas-checks stay!

Nice! Personally I would use more lube on the sides of the bullets to help prevent such issues

I v had fantastic results with these
30-06

with my 1903A3 Springfield

although my only issue with these is that I end up with a little extra lube over the groves. Look at the 2nd one from the right.

quote:

Originally posted by James Kain:

quote:

I can't seem to find any 32 cal gas checks.

https://www.hornady.com/shop/?...2a2b50048cd45ecc5661
http://www.lymanproducts.com/l...sting/gas-checks.php

Damn checks are getting up there in cost! I have a few colorful words for those who chose to make life harder then it has to be!

Thanks for the link! They are getting up there! I need to check what the actual size is for those 8mm gas-checks. I have a suspician they are .323. I need .314. I'll check out my local supplyer to see what he can get me. I have visions of either modifying my 30 cal gs-checks like I have been doing or making my own.

email them and ask if they sell them in 314 I would also check with some online supplyers as well as Dave Corben. http://www.corbins.com/ or his brother http://rceco.com/MN.asp?pg=default

Thanks for the link! I shall do that.

Hey 303 send me your email, I will forword you a email I got from dave.

303 talk to pat marlin over on the other board he should be able to bump one of his 30 cal check makers up if you need.
or get you the parts to do it your self.
you should then be able to make or redo the factory ones.

Thanks Lamar. At the moment I flare the 30 cal gas checks to get a tight seal in the base of my mound - the gas check is the base of the mould!

with a simple ram and a disc of copper aluminum and your machining skills a 314 should be easy enough.
i haven't tried 314 but i have had good sucsess with 313 and regular 30 cal g/c's
the punch making them bigger is what most guy's do. if you anneal them it is easier.

Well, I made case bullet with a brass ring near the base. It broke off at the ring - which was a brass eyelet. I somehow don't think this is going to be a starter. However, boat-tailing the gas check seems workable. Either flaring the rim of 30 cal gas checks or making a punch set to make my own.

This one still has the gas check as that is the 'base' of the mould.

quote:

Originally posted by 303Guy:
Well, I made case bullet with a brass ring near the base. It broke off at the ring - which was a brass eyelet. I somehow don't think this is going to be a starter. However, boat-tailing the gas check seems workable. Either flaring the rim of 30 cal gas checks or making a punch set to make my own.

This one still has the gas check as that is the 'base' of the mould.

Looks like you my just need more lube bands to help with the current issue I ll add photos to this post tomorrow.

quote:

Looks like you my just need more lube bands to help with the current issue

The idea here was to add a boat tail to the bullet to facilitate a mould base 'cap' and to fit the brass or copper seal further up the base of the bullet. Lube is done on the nose of the bullet the same way as a 22rf. I have taken to adding an additional waxy-lube wad to my loads which is simply a blob of molten waxy-lube on the base of the bullet. This works fine so far. The absence of lube grooves also increases the weight of the bullet without increasing its length which was one of the original objectives.

i don't understand the boat tail thing.
usually a square base is desirable so that the g/c acts as a scraper of any lead in the bbl and to give strength to the base.
it is also well... a gas check.
if you are having good results[accuracy] and no leading,you might be at a point of diminishing returns here.
unless your goal is to get high velocity.
i know you are wanting to use these for hunting and i think you are about there.

Have you contacted one of the Corben brothers yet to see about there "Half Jacket" AKA "Short Jacket"?
I m hoping to be able to buy a hole set from dave soon but money is tight!

I like the boat tail idea. The only thing that would make it better is if we could test it! Do you have any friends who are machinists or know of a machine shops in your area who would help you out? Maybe contact Lyman or some other company's deal with bullet dies and see if you guys can come up with something? If it works maybe you can get payed commotion!

quote:

... the g/c acts as a scraper of any lead in the bbl and to give strength to the base.

Well, yes ... I had never fired an un-gas checked ullet at these pressures and velocity before and did not realise the gas check gave the bullet base strength! The 44mag might have run at quite high pressure but the bullet was shorter and the pressure duration would have been shorter. (Lead 'flows' under pressure which takes time). Afet testing a gas check-less bullet anf capturing it I realized there will be no getting away from it. I thoght too, that I could use the bot tail to carry way-lube but there too have found the flat based, gas checked bullet carries the waxy-lube just fine. Another consideration was bullet base 'deformation' from the rifling. I shall instead be concentrating on a 'slightly' boat-tailed gas check, either a mof=dified 30cal or one I have made. I have not had time to look at the punch set yet nor have I had time to contact the Corbon brothers yet. (Another way of saying I haven't gotten around to it yet!)

quote:

Have you contacted one of the Corben brothers yet to see about there "Half Jacket" AKA "Short Jacket"?

No, not yet. I am a machinist myself so I can in fact make most things I need. It's the time I am a little short of (I have 'other' projects on the go at the same time) and of course not knowing the proper designs - meaning I have to experiment some!

quote:

i know you are wanting to use these for hunting and i think you are about there.

Thanks. Yes, I do believe I need to pursue my current 'developements'. I have been able to shoot some of these bullets out my two-groove barrel without flame-cutting and since this is the rifle that is field ready, I should give it a go! (It has a suppressor/muzzle break and carry cord).



This is a bullet fired before fire-lapping.


This one was fired after fire-lapping!

Three things are apparent in this pic - base deformation, absence of 'smearing' and bullet slump near the middle due to impact forces. This 'slumping' is what would would distort a normal lube-grooved bullet. In this design, the bullet is fully supported by the bore and provided the base stays square (needing a gas-check) and the lube works (which appears to be the case), the bullet should shoot straight. The pressure behind this particular bullet was reasonably high - for lead!

quote:

No, not yet. I am a machinist myself so I can in fact make most things I need. It's the time I am a little short of (I have 'other' projects on the go at the same time) and of course not knowing the proper designs - meaning I have to experiment some!

Funny thing is, I m going to be starting a program in the fall for a machining coarse at a community college. At the end I will have my associates degree in "Procession Machining".

Besides experimenting is the fun and best part!
Keep me informed!

PS I hope I spelled all that right, I used the spell check and am unsure if I added the right spell type.

quote:

I m going to be starting a program in the fall for a machining coarse

As we would say down under - Good on ya Mate! I trust it will go well!