Tell Me My Future

[Tech2]

I have been casting for six months now. I have three rifles that I cast for
a K-31 Swiss 7.5mm
SKS 7.62 mm
Mosin Nagant 7.62mm
I have a 20LB Lee pot and 1 Lee mold C312-155-2R
I have collected a few hundred pounds of lead and cast about 1300 boolits from 2 batches. Hardnesses are about 12 and 24
Mostly I reload for the SKS 24gr of RL10x in Yugo brass with a gas check at just over 2000fps. faster and the boolit vaporizes about 50 yards down range poof small white cloud!! The Swiss crowd has a fair amount of knowledge HBN Hexagonal Boron Nitride and I like to use it as well.
I tumble lube with my own formula of Johnsons paste wax mineral spirits HBN and a little LLA. I keep it in a sealed jar. To apply it I heat the lube and boolits on a coffee cup warmer pour the liquid onto the boolits, slosh and drain the fliud back into it's can. a day later I have a nice hard coating loaded with HBN.
I get no leading and other than the boolit exploding from the 9.5-1 twist of the SKS this all seems very robust.
Where can I expect this to fall apart and where has your path taken you next?

[MBTcustom]

I see many questions about your "exploding boolits" in your future.
I see much BS being called on this assertion.
I see you becoming a much more knowledgeable shooter in a very short period of time.
I see many good comments to this thread in your future.

[waksupi]

Uh- first, your boolits are not exploding or vaporizing down range. Otherwise those of us pushing them up around 2800 fps would never see a hit on the targets. You have a wrong assumption.

[Tech2]

This is why lead is more fun than copper.
I puled up my chrony notes for the day with the vaporizing boolits.
powder RL10x
Rifle SKS
http://www.sksboards.com/smf/index.php?topic=101960.msg1228398#msg1228398
lead was a mix of ww and reclaimed sheet lead, there seems to be a fair amount amount of antimony in the ingots that I started with.
dropped into a wet towel.
HBN on the outside and Felix in the grove.
shooting through the chrony with no paper.
Anything over 24 grains 1850fps would not reliably impact the berm at 200yds and would make a poof at about 50 yds our assumption was that they were spinning too fast and coming apart.
I read someones post suggesting that lead would come apart around 2000fps in a 9.5-1 twist barrel.
My latest batch of harder boolits hasn't had any issues but I have not taken the chrony out to see how far I can push them.

[MBTcustom]

Cast lead boolits do not spin apart. I have heard of jacketed bullets spinning so fast that they will sling the jackets off of them, but this was with either the 17 remington and the 220swift cartridges pushing the projectiles close to 4500 FPS. 2000 FPS is not even a moderate speed for a 30-30.
I don't know what your "poof" is, but it is certainly not your boolits coming apart. One of the strengths of the cast lead boolit is its inherent ability to hold together because it is made of only one material.
Also, you need to understand that cast lead boolits need a little extra TLC in order to get good results.
The first thing you need to do is slug your barrel to determine what your groove diameter is. Then you need to make sure your boolits are at least .001" over that diameter.
Second, you need to experiment with different boolits to find the one your barrel likes. There are many members here that will send you samples to try.
Also, move your target up to 50 yards so that you can see what is happening. If you found a cast lead boolit load that put you on paper at 200 yards first rattle out of the box, then you would be a very lucky fellow indeed. You start at 50, and when you find out what your rifle likes, then you move the target back.
I dont see anything glaring about your setup that is wrong, except that you mention nothing about your groove diameter which make me think that you might not have known about slugging?
FWFL is the right lube to be using at the speeds you are shooting, so kudos to ya.
Can you go into any more detail about this "Poof" that you are seeing? (that is, unless you are pulling my leg which has been known to happen.)
I hope you took no offence to my earlier post, you wrote it in a humorous way, so I followed suit. That's about the most off the wall title I have ever seen on a post here (no offence intended).

[geargnasher]

Lube is spinning off in a "poof". If it's more like 300 yards downrange it would be the air disturbance from the transonic shift causing the visual.

Gear

[1Shirt]

I am in line with Waksupi's comment. There is a fish in Denmark here I think!
Suggest you try straight WW's water dropped, and report back on results. I have blown hornet blts out of 223's and 22-250's just to see that it is possible as X vol.
However, have been shooting cast for over 50 years, and some much hotter than your listed vols. Have taken 224's up to 2500, and 30's to over 2200 and never anything be some leading on occaision until I got to the right size.
1Shirt!:cbpour:

[Tech2]

No offense and no fooling.
I am having a good time learning to reload and cast.
The SKS will chase a beer can all over the place at 75yds so I am fairly happy with my current load.
I should probably make some hotter loads and take some bigger paper out to the range to see if I get 1 hole or a shot pattern.

[MBTcustom]

Can you describe the "Poof" a little better? I am certainly interested in what is causing that. I like boolit trivia, and that's something I have never heard of before.

[Hamish]

http://www.sksboards.com/smf/index.php?topic=101960.msg1228398#msg1228398

Welcome. I can't fortell your future, but I like the work you did, and it sounds like you're doing just fine so far.

The only "poofing" I have read about has been .22 sized boolits being pushed up in the 3K plus region, IIRC.

[waksupi]

Going faster, will just make you miss further. I suspect the puff you are seeing, is your wildly inaccurate bullets landing at odd places down range. Get the right size boolit first. With your current mindset, you are not headed for success.

[Tech2]

I am not trying to yank anybody's chain in fact I was just looking for some advice on where casting would take me next .
The mold that I am using is an Ed Harris design specifically for the SKS
The major diameter of the cast boolit is .312
The minor diameter of the bore is.302 I haven't slugged it for the major dia.
The poof happens at about 50 yards out and 5' off the ground. On target if I had set one up.
If I had known this was something out of the ordinary I would have investigated it a little better. I just assumed that I had reached the performance edge of the projectile.

[MBTcustom]

I just assumed that I had reached the performance edge of the projectile.
Nope, your'e right where cast boolits like to live.
You should slug your barrel, because its the only way to find out for sure what size you need your boolits to be. Its the first thing I do when I get a new rifle.

The poof happens at about 50 yards out and 5' off the ground. On target if I had set one up.
I have never heard of this before, and I would love to see it and help you find out what is happening. You don't live in Arkansas by any chance do you?
I'm racking my brain, but for the life of me, I can't imagine what would cause something like that. 50 yards is too far away for your lube to be doing anything hokey, and its too close to be crossing the sound barrier if your going 2000FPS at the muzzle.
Very strange.

[waksupi]

You haven't slugged you bore, right? Just because a design is supposed to be for a particular firearm, doesn't mean your bore dimensions match what the mold drops.

[Tech2]

I know stop talking and find the answer right!
My only means to slug the bore tonight was to use a boolit.
I tapped it in a 1/2 inch and pulled it out with the vice grips just barley.
The major diameter is .311-.312 and I have a shiny contact patch all the way around.
The bore was getting tighter as I tapped the boolit in.
I'll try to get a sinker and do it again a little deeper.

[waksupi]

I get the giggles every time I look at this topic. I'm getting out, and will let Tim and the other guys handle this. But I will be watching! It eases the load!

[geargnasher]

If your "slug" boolit turned to "barley" when you put the Vise-Grips to it, no wonder they're vanishing in a white puff at 50 yards! You should be making beer out of them, not boolits. :kidding:

Seriously, you ain't gonna get any meaningful numbers unless you use pure, soft lead. .311" or .312", which is it? It matters. Cast a couple of boolits from some split-shot or pure lead solder and try that. Also, drive them all the way through the gun, just checking the muzzle won't necessarily give you the true groove diameter.

Gear

[fcvan]

I've seen boolits come apart. I've also seen bullets fired from a 220 Swift that flew apart. The 220 was going too fast for a thin jacket that couldn't take the speed and rotation.

The boolits that flew apart had internal impurities from poorly fluxed badly contaminated alloy. We assumed the centrifugal force acted on the inclusions within the boolit which caused separation.

We pulled the bunk ones and cut into them. The best way to describe it was slag suspended within the boolit. Turns out the novice was ladle pouring and had never heard of fluxing. He just stirred the crud into the mix and figured it was mixed in. Re-melting and fluxing cured the guy's allow issues and he turned out to me a great booliteer. Frank

PS, the fastest I have launched was the Lyman 225-415 cast with wheel weights, launched at 2250fps from a Mini-14. The boolits didn't come apart but the tin cans sure did!

[geargnasher]

I've pushed air-cooled wheel weight alloy to over 2700 fps in a .270 (paper-jacketed) and never had one come apart. Over 2600 in .30-'06 the same way and also without the paper, and never had one blow up in midair either. I maintain the lube is coming off, probably gets melted by the air friction at a certain point and lets go.

Gear

[fcvan]

Gear, I was going to go with the lube flying off due to friction too. He said he tumble lubed them with JPW, LLA, and mineral spirits and then Hexagonal Boron Nitride. I don't know what that is but maybe that is whats separating when the heat from friction takes it's toll. I can't help but think that such a change in the rotational mass would cause the boolit to spin off like a curve ball. Frank

[MBTcustom]

Although not ideal, you can use a boolit to slug your barrel. If anything it will spring back a little upon exit and give you a few ten-thousandths of an inch over-sized measurment, but thats OK because if you make your boolit over-size by a few ten-thousandths, you are erring on the side of safety. The proceedure is to take a piece of 1/4" aluminum rod (they sell it at the hardware store) and cut it into 6" pieces. You also need a plastic faced hammer.
First, clean your bore with and amonia based cleaner until your patches stop coming out blue. When you get all traces of copper fowling out of the bore (which is a nesissary thing to do anyway if you are going to be shooting cast lead) run an oily patch down the bore. Open the breech of your rifle, and take the bolt out. If that is impossible wad up cleaning patches on your bolt face to be a kind of "catch pillow" for the slug when it exits the barrel, otherwise put a towel down on the ground to give a gentle landing to the slug as it drops from the breech.
Take one of your boolits and hammer it into the bore with the plastic faced hammer. Be gentile but firm. Use the first 6" piece of aluminum (choose the one that came cut square from the factory as the pushing face, as any curve or chamfer will have you cussing me tomorrow) to drive the boolit down the barrel. Once you run out of rod, follow with the next and the next until you get it all the way through the barrel.
As you do this, watch and feel for tighter, looser, grittier, spots in the barrel and note what you felt and where. Take your slug and observe it with a magnifying glass or a loupe and carefully observe if you got good clean rifling marks all the way around the slug. If there are places around the slug where you can see that it didn't quite seal up the bore, then your slug is no good, do it again. This time, smack the slug on the nose with that hammer a few times on your work bench to make its diameter bigger and then repeat the process. When you are satisfied that you have a good specimen that truly resembles your barrel's characteristics, you can start gently measuring with a micrometer. Only a micrometer will do for this application. If you don't have one, you need to get one, and you can contact me to teach you how to use it if you don't know.
Now, remember that back when most military rifles were being made, lots of manufactures cut rifling one groove at a time on a steam powered rifling bench. Ordinarily this is a superb way to cut rifling in a barrel, but in a war time situation, sometimes they got sloppy. Sometimes they would get a barrel that had oblong rifling, sometimes one groove is deeper than the others, sometimes all the grooves are too deep. I have a barrel off of a British enfield #4 MK1 that should have a groove diameter of .312, but in fact its closer to .320.
This is the only way to find out the true characteristics of your barrel and like Gear said, It matters! .0005 can be the difference between victory and defeat.

[Wayne Smith]

You don't tell us where you live. If you are in a very humid environment and you are shooting a boolit faster than the speed of sound, when it returns back through the sound barrier you can get a 'smoke' ring, a ring of humidity that is turned visible by the turbulence of the boolit going through the sound barrier.

[MBTcustom]

If you are in a very humid environment and you are shooting a boolit faster than the speed of sound, when it returns back through the sound barrier you can get a 'smoke' ring, a ring of humidity that is turned visible by the turbulence of the boolit going through the sound barrier.
That's true enough, but he says that his boolits are going 2000FPS at the muzzle. How do you loose 1000FPS in fifty yards? I would have thought it would be crossing the sound barier at closer to 300 yards.
Like so: (just punch in a 170 grain projectile going 2000 FPS and hit "calculate")
http://www.handloads.com/calc/

[Wayne Smith]

Just wanted to throw another as yet mentioned option out there. I have no idea how accurate his numbers are or where he lives and shoots. Condition is everything, even the speed of sound!

[Four-Sixty]

I have cast from purely reclaimed shot. I've noticed if you smash a boolit soon after it is cast, it crumbles. The smashed boolit breaks apart like a pile of salt.

Oddly, a month or so later the boolit, when smashed, "smears" like a typical piece of crushed lead would. It also "rings" pretty sharply when struck.

Unless you've seen it yourself, be careful about disclaiming its validity. But, the author of this post would be well served to post pictures of targets struck by these disintegrated boolits at the distances claimed.

Please also see from "Ingot to Target" for more info on the "friable" (to borrow a soil term) nature of antimony.

[MBTcustom]

I have cast from purely reclaimed shot. I've noticed if you smash a boolit soon after it is cast, it crumbles. The smashed boolit breaks apart like a pile of salt.

I'll be dogged. Never heard of that before. Still, 2000FPS is rather anemic speeds and I don't see why the boolits would make it all the way to 50 yards before going all frangible.
I would love it if this were actually what was happening. Can you imagine the varminting applications? Splodin' boolits = awesome.

[Tech2]

I am in Seattle so weather is always a factor but it wasn't raining.
It was a clear enough day that my Chrony was actually reliable.
My son and I were out doing basic load testing for 7.62x39 in the SKS
22gr RL10 - 1642 fps
23gr - 1750 fps
24gr - 1850 fps
25gr - 1950 fps
26gr - 2025 fps
27gr - 2055 fps
It was around the 24 gr mark that things stopped hitting the berm and started making the white poof at 50 yards. It is possible that the two are not even related.
The lead was first cleaned and cast into ingots then remelted and fluxed with wax to cast the boolits.
I used a mic good to .00005"
The reason for the .311 -.312 is because that is what the two sides measured. This probably had something to do with the Vise Grip removal technique that I used.
Here is the range that I worked from.
http://www.cascadeshootingfacilities.org/html/b-range_3.html
The rear berm is fairly hard to miss but not impossible.
I have a 24" x1/4" brass rod that I was intending to use to drive the slug with.
Do I need to cut it up?
A plastic hammer was emphasized what is the significance?
I'll try to buy some sinkers today, I don't have any dead soft lead.

[MBTcustom]

I have a 24" x1/4" brass rod that I was intending to use to drive the slug with.
Do I need to cut it up?
A plastic hammer was emphasized what is the significance?
No, you dont need to cut it up but its a pain to drive a long rod. However, if you use a long rod, you can keep it from landing on the slug and damaging it. It is helpful to have at least one section of rod 6" long to help get it started, but after that its no problem.
The significance of the plastic hammer is so that you can hammer the slug into the crown of your barrel without causing any damage. Remember that you are driving in an oversize slug and it is a little hard to get started if all you have is a 1/4" rod. The plastic hammer lets you smack it until its flush with the end of your barrel without causing any damage. Of course, you may have a different situation with an SKS, but the fact remains that a steel hammer has very little use around firearms.

[grouch]

I've pushed a 150gr Lee flat point bullet (ww+2% tin water dropped) to over 2500fps with 44gr of H4895 ina 30-06. Not match winning accuracy, but not all that bad. No sign of disappearing bullets. Thinking back to my beginnings 50yrs ago, most of my early problems were alloy related. I suggest you start looking for your problem there.
grouch

[MBTcustom]

Boolit fit is king, lube is queen, hardness is your jack and boolit geometry is your ace in the hole.

[ElDorado]

The SKS will chase a beer can all over the place at 75yds


The poof happens at about 50 yards out and 5' off the ground.

Can you explain this? If the boolit vaporizes at 50 yds, how does it hit a beer can at 75?

[popper]

Ok - you didn't state what you alloy is. Poorly poured CB could have weak spots. Non-stabilized fast bullets will tumble and can frag, close to 'exploding' or go in unknown directions rapidly but not vaporize. I've heard this comment from others so I believe it CAN happen.

[Tech2]

I bought a bag of sinkers today. The hollow football shaped ones.
I ran it through the sizer at .3075 then smacked it with a hammer to plump it back up to .320
I cleaned an lubed the barrel.
The slug was started with a brass punch then finished with a brass rod and caught in a cloth.
It had good symmetry and the bore drag was very consistent.
the major diameter is .31265
the minor diameter is .30215
My as cast boolits measure .31240
I had a hardness tester lined up for my next purchase but it looks like there may be a new mold in my future.
Tim thanks for the great slugging tutorial. You were so specific about the plastic hammer that I thought that I better ask if it was just a potential damage issue or if something really bad was going to happen like the slug getting wedged into the bore from the sharper impact.

[MBTcustom]

Ahah! Its like I'm psychic or something. I told you I could read your future!
You need to hone out that mold so you get your boolits to drop .314 at least.
I still don't know what you are seeing at the 50 yard line, but your boolits are definitely undersized. You are going to have problems if you don't get that fixed.
Fit is king.
Use one of your previously cast boolits as a lap, along with a mild abrasive of some sort to gently lap out the cavities to a larger size. If your boolits have bore rideing sections and they are the right size, cut the noses off with a hack saw, and only lap the driving bands.
You would do well to invest in some cerosafe chamber casting alloy. Take the cold mold and cast the cavities and measure what you have now on all the surfaces that you intend to lap. Use this as a baseline and lap them larger from that point, using the cerosafe to tell you how much you have taken out. I say this because the mold is designed to expand when heated, and the boolit contracts as it solidifies, so the cold measurement of your cavities will be slightly different from the final size of your cast boolits.
Did you feel any tight/rough/loose spots?
Did you clean with an ammonia based cleaner to get all of the copper out of the barrel?

[MBTcustom]

I forgot to say, use a drill and tap to thread the bases of your boolits and screw in a bolt. 10-32 or 8-32 would do the trick. You can drive the laps with a wrench, or you could use a hand drill.

[Tech2]

The camera finally came home
Here is a slug and a boolit that I sharpied then slugged the bore with.
http://i755.photobucket.com/albums/xx196/hansen_acura/slug.jpg
as cast and lubed with jpw and hbn
http://i755.photobucket.com/albums/xx196/hansen_acura/lubedboolits.jpg
The 1000 boolits that I will now be saving for my K-31
http://i755.photobucket.com/albums/xx196/hansen_acura/1000boolits.jpg
A little stock for my next batch
http://i755.photobucket.com/albums/xx196/hansen_acura/lead.jpg
The gas check fits nicely so I don't want to bore it out but what about the pattern you see on the nose of the sharpied boolit ? Grind or stay away ?

[MBTcustom]

I can't see the other side of the boolit. If the driving band just in front of the GC is .001-.002 over the groove diameter of your rifle, then I would say give 'er a try. Ideally you would want to black a loaded boolit, chamber it, and see light rubbing from the lands on the bore riding section. Not to say that is a necessity, but if your groups are shoddy its something to try. You can cut whatever part of the boolit off that you don't want the lap to touch. If you just want the driving bands to get it but not the GC shank or the nose, cut those parts off and lap with the section that is left.
Of course, if you have a little bit of money to invest in this hobby, you could just order a custom mold from Accurate. Those molds are not very expensive and Tom makes them exactly to your specifications.

[Wolfer]

Apples to oranges here but I've seen many Sierra blitz bullets blow up when shot from a savage 223 with 9" twist @ any speed above 2800 fps. Several different rifles. A few would poof a few feet from the muzzle but most of the poofs ( about 50 % of the total loads fired ) would be a puff of gray smoke about 30 to 50 yds out. Our two Remington's with 12" twist shot them just fine. This happened with one batch of about a thousand bullets. I've shot them in the past up to 3000 fps with no problems.

[geargnasher]

Personally, I prefer making impact slugs of the chamber/throat as opposed to casting with anything. The slugs don't shrink or lie to you, and are easy to make if you have the right stuff.

First, take a fired case, hold it with pliers, and fill it up with boolit alloy to about halfway up the neck. Next, take some of those soft sinkers and cast two or three boolits. The mould can be cold and wrinkles don't matter. I use a small Au-jus ladle and a propane torch for melting micro-batches for this, and use the torch to knock the chill out of the sprue plate just before pouring. Lighly oil the boolit and throat, set the boolit in the lead-filled cartridge and chamber it. This might take a lot of force on the bolt to get the long-seated boolit to extrude up into the throat. Now take your brass rod and wrap it with one layer of electrical tape. Take a gas check and start it in the muzzle end with a punch, and hammer it all the way down to the boolit nose with the brass rod, making sure it stays square. When it contacts the tip of the boolit, keep hammering until it doesn't want to go any more, but use common sense here, it doesn't take much to mash that soft lead to conform to the details of the throat, but it might take more than you think. It depends on what you're expecting. If you didn't forge it enough, you can always do another.

Now extract the cartridge. If you're careful, sometimes you can leave the rod in the bore and put it against the floor and push the rifle down against it while opening the action to keep the "boolit" and cartridge together, but if they come apart you can just put them together after you push the slug out of the throat. Be careful not to hammer the slug out, or you'll mushroom the tip and spoil the true dimensions of the leade.

Now you'll have something to measure, look at, and it will be as good today as it will next year, unlike Cerrosafe. Making an impact slug is also a very good way to measure true chamber neck diameter, see if the chamber is concentric with the bore, and determine maximum safe trim length for your brass.

Gear

[Tech2]

Gear unfortunately the SKS magazine keeps you from pushing the boolits out far enough to engage the rifling. My guess is about .050" away from the rifling at the max that will fit in the magazine.
Nothing like showing up to the range and finding out that you can only load 2 rounds at a time in a semi auto! Interesting technique on doing a chamber casting.

[geargnasher]

So how does the magazine interfere with making a chamber/throat slug?

Gear

[Tech2]

The Yugo brass is on the short side, after three case cycles I barely get to touch up the nose.
The magazine prevents me from properly setting the projectile depth.
Throat condition and dimensions would be nice.
I see your point
when troubleshooting odd problems knowledge is king.

[MBTcustom]

I'm not sure if you quite get what Gear is recommending, if you do, disregard the following.
A chamber slug is the same as a barrel slug, except it gives an accurate rendering of the area of the breech and barrel just in front of a chambered cartridge. In the SKS platform, the bolt is unlocked and thrown back by the gas rod, and not recoil, so that means that you can pound on the bolt all you want to, but it will not open unless it is pushed by the gas rod or pulled by the charging handle.
What Gear suggested you do, is slide a soft slug into the breech followed by a cartridge case filled with lead. Then, take the rod you used to drive the original slug down the barrel, and use it to drive the new slug down into the cartridge case full of lead. Since the case is full of lead, the slug cannot go down so it must go out, filling the chamber and capturing every detail of the throat of your rifle.
It has nothing to do with the magazine.
It is simply a more accurate way to get a good chamber impression than cerosafe.

[geargnasher]

Before and after, like so:

http://castboolits.gunloads.com/imagehosting/thum_89094fe91dc00c780.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=5677)

Gear

[Tech2]

Here is the cast
http://i755.photobucket.com/albums/xx196/hansen_acura/chamberslug.jpg

four sides
http://i755.photobucket.com/albums/xx196/hansen_acura/side1.jpg
http://i755.photobucket.com/albums/xx196/hansen_acura/quarter.jpg
http://i755.photobucket.com/albums/xx196/hansen_acura/half.jpg
http://i755.photobucket.com/albums/xx196/hansen_acura/threequarters.jpg

The magazine issue
http://i755.photobucket.com/albums/xx196/hansen_acura/tapcomag.jpg

What I think that I am learning
The chamber diameters are consistent at the breech and muzzle
A .314 round will chamber and may touch the rifling
I didn't find any lips, burrs or misalignment.
The brass could grow an 1/8" and it would still chamber and release.

[bowfin]

Could you tell us for what you are using the Hexagonal Boron Nitride? For a boolit coating, or a mold release agent?

[45-70 Chevroner]

Tech2!!
To get a proper measurement on Wolf and S&B ammo I had to pull the bullets. The Wolf FMJ measured .311" and the S&B FMJ measured .3115. When I measured the bullet while still in the shell they measured .308 right at the junction of the mouth of the shell.

[Tech2]

I tumble the boolits in hot Johnsons paste wax and HBN cut with a little mineral spirits. fully drain and let cure for 24 hrs. I am not a fan of greasy boolits.
You can't impact transfer the HBN into lead so I put it into a carrier.
I burnish my molds with Tungsten Disulfide WS2. You can feel it start to wear off at around 200 drops. I think that it is a great way to break in a new mold.
I bought the dry lubes here
http://www.derbydust.com/xcart/product.php?productid=18&cat=4&page=1

[runfiverun]

i bet that lee crimp has something to do with it.

[geargnasher]

You need a totally different boolit. First of all it would probably work best right at .314" provided the brass neck thickness still allows you a little chamber neck clearance. The neck has to expand to release the boolit, and also the autoloaders need a hair more clearance than typical bolt guns to ensure reliable feeding. I don't think your slug's neck dimension is true, though. It doesn't look like you filled the case with lead, and it doesn't look like the neck expanded to full chamber neck size when you impacted it except maybe in the 1.4 view, I see a little shiny ring on the neck where it might have touched. If the impact slug does show a true, full-dimension of the chamber neck, you won't be able to use a boolit bigger than the ones you already are because they won't chamber. If the chamber neck is .340" and your boolit is .314", and you need .001" total clearance as an absolute minimum, that gives you .025" for brass. Measure the thickness of your brass at the neck, if it's .013", then you have basically an interference fit with a .314" boolit, so you'll need to look for something more around .3130-.3135". However, like I said, I seriously doubt the .340" chamber neck is even close to true dimension, I'd think more like .346-8" would be more like it in an SKS, but I've been wrong before and every gun is unique. That's why a chamber slug is so important!

When you fill the case with molten boolit alloy, it anneals the neck and upper part of the case enough that it will easily deform to the exact dimensions of the chamber, especially the neck area. This chamber neck dimension is important to know so you can tell just exactly how large a boolit the rifle will chamber, and also if this is larger than the throat will accept. You don't want to go much larger than the throat with boolit size unless there's a smooth transition between throat and chamber rather than a step at the end of the chamber like many American guns have because the step will shave lead. It looks like your chamber has a nice transition to the throat from the pics of the slug, so that works in your favor with shooting really fat boolits. Also, you can turn your case necks a tiny bit if you need to to fit a larger cast boolit.

The other thing that's wrong with your boolit is the nose is way too small. See the shape of the throat on your impact slug? See the huge amount of unsupported nose area and how poorly the boolit fits the throat? If the boolit doesn't get a straight start into the barrel, it won't shoot well at high velocity. The boolit nose needs to basically be a mirror-image of the throat shape so it will start straight now the centerline of the bore instead of hitting one side of the throat and glancing into the barrel. If the nose gets bent and distorted during launch, all sorts of wacky stuff can happen downrange.

Also, try a little less of that killer FCD crimp like Run suggested. I know your brass length is probably erratic due to the brand and what you're trimming it to which would preclude a roll-crimp in the groove, but you're really killing it. If that's what it takes to keep the boolits from setting back in the magazine under recoil, you need to investigate a harder alloy, because case neck tension is what should be doing most of the work, not the crimp.

Gear

[Hamish]

I would like to thank Tech2 for hanging in there, this is becoming a very informative thread. Stay with it fella's.

[geargnasher]

....and the great pictures sure help out a bunch!

I apologize if I mired this down with all these little details, but they matter if you're shooting higher velocities and want to maintain your group size.

Basically I'm zeroing in on the SKS since it's the one you shoot most and are having the "boolits go poof" thing happen to. The concept is to eliminate boolit tumbling, wobble, yaw, and embalance that ruin accuracy once you exceed a certain velocity. To do this, lots of things have to be right, primarily getting the boolit to start straight in the barrel. With relatively soft lead-alloy boolits, lots of extra considerations have to be made, like close chamber neck clearance, good boolit/throat fit so it's supported fully and can't get unevenly deformed when the powder shockwave hits it in the base. Boolit design is important here, this is where you measure your gun first and work backwards from that to find the mould you need (or have a custom one made which is more likely to be what you'll have to do here), the brass you need, trim length, OAL, and then when you put it all together you need the right expander for your brass to keep the boolit from being deformed when seated, the right crimp to keep the driving bands from getting raked off when it's fired, the right powder and charge weight for the barrel, and the right lube.

Or, back it off to about 1800 fps and use what you have, it seems to be working, but I just wanted you to "get" what you're up against shooting cast at high speed, and give a little insight into what goes wrong to cause accuracy to go south.

Gear

[Tech2]

If I don't crimp, the boolits are sloppy loose. If I use the smaller mandrel for copper jacketed then the gas check is a bear to push through. I could crimp less.
I made the case by pounding dead soft 1/4" fishing weight lead in up to the bottom of the neck then sized the round. It was a bit lumpy.
I chambered the round then added a 1.5" piece of 1/4" lead down the muzzle and began tamping it in with the 1/4" brass rod and a hammer. The impact definitely changes when everything fills up. Several more hits around the periphery to assure 100% fill then I had to use a brass punch on the exposed upper bolt head to pop the shell loose. It looks like it has a 100% fill and I believe the neck fully expanded as well because there is no lip between the brass and the lead.
I will measure the wall thickness of the brass. I was wondering as well if I would have enough room to release a larger boolit.

Thanks for the help
You know your bursting my ignorance is bliss bubble!

[geargnasher]

Using a crimp to hold the boolit? No wonder you're having issues.

As to making the impact slug, I gave you very specific instructions, and for a very good reason. Take a FIRED, UNSIZED case with the expended primer still in place, fill the case up with MOLTEN BOOLIT ALLOY, not soft lead, leave about half the neck empty for your lead boolit. The reasons behind this are many. You want the case to be as close to chamber size as possible to begin with, hence the fired, unsized case. You screwed it up when you sized your case after filling. The case needs to be annealed in the neck/shoulder area to give you true measurements, filling it with hot alloy will do this. Using harder boolit metal to fill the case instead of pure keeps the case body from collapsing too much when you pound on it, but still lets the neck part expand. Filling the case with molten metal assures no lumps.

Now follow me here on boolit fitting the case: You need somewhere around a 1.5-2 thousandths interference fit beween the boolit and the resized case neck. That tension is what holds the boolit, holds it straight, and gives the initial resistance for the powder to build pressure against so it can reach a clean peak burn.

So, measure your sized case neck ID to see what the die and various expanders are doing to it. You might have to ditch the expander in the case and get a different one, or if you use a bigger boolit it might be perfect. Lee dies come with two expanders, I believe (.307" and .310", am I right?), I see you've tried them both, but the .310 shouln't leave your boolits "sloppy loose" if they're .312", in fact they should be maybe just a little tight still since the ID of a case expanded with a .310 spud should still be about .309". Something isn't right here.

The "quick and dirty" way to tell the largest boolit your rifle can safely chamber is to just measure the inside of a case neck fired in your particular gun. YOU MUST REMOVE ALL CRIMP with a bellmouth tool, tapered punch, or use a ball micrometer designed for the purpose. You can get a decent measurement with accurate calipers if the case mouth is perfectly tubular and has no crimp or bell to interfere with the measurement.

To double-check the above, use a hammer on the nose of a boolit to fatten it up a bit and insert it into a bellmouthed, fired, UNSIZED case. When you get a snug fit that you can still pull out with your fingers, but with some effort, mic that and you'll know how big you can go.

Gear

[geargnasher]

Another question, which just occured to me, what type of belling tool are you using on the case mouths?

Gear

[popper]

he may be stuck with that bullet design as the mag won't take a bigger nose. long throat but no space in mag.

[geargnasher]

he may be stuck with that bullet design as the mag won't take a bigger nose. long throat but no space in mag.

You're missing my point too. I'm talking about a FATTER nose to fill the sides of the throat, not a LONGER nose to fill the leade and engage the rifling. If the nose fits the throat, it doesn't need to be seated into the rifling to shoot straight, but a .303" boolit nose rattling around in a .314" throat and wonky case tension and killer crimp ain't a good recipe for accuracy at any velocity. There's plenty of room in the mag for a fatter nose.

Gear

[MBTcustom]

Tech2, listen to the man; he speaks wisdom! Also, you could email those pictures to Tom at Accurate Molds and he will design you a custom mold for your rifle. Its not as expensive as you might think!
I agree with Gear, you need to fill a fired case with lead and pound that sucker in there. Anything else and you will have false readings. You should have a light press fit in the neck with a new boolit. A roll crimp is nesissary to prevent sizing the boolit down when crimping. You want to load a cartridge and then pull the boolit and measure it to determine if it is the same size that it was when it was loaded in the case. None of this amounts to a hill of beans if the boolit doesn't arrive at the barrel the same size as it left the sizing die.
Keep at it buddy, your getting closer! I'm having flashbacks of my first thread on cast boolits. Many waters under the bridge.

[Tech2]

All my bad habits coming back to bite me.
I started reloading for my Swiss K-31. The roll crimp on the Redding Dies would either fail to crimp properly or crush the neck of the brass. The Swiss is a straight pull and does not tolerate any flaws in the brass. When I bought the 7.62 x 39 dies the Lee crimp seemed like the obvious answer.
I bought the Lee SKS mold figuring that I could leave them full sized for the SKS and size them down a little for the Swiss.
I have a few new measurements
The throat measured .342 and has a slight taper per the ball gauge.
My slug measures .340 and has no taper. I know I know
The Yugo brass has a neck thickness of .0105" and is fairly soft
The Lyman gas checks have an OD of .318 and a wall thickness of .0165"
Since I haven't been sizing the SKS rounds that means the GC has been resizing the brass for me when I seat the boolit.
I didn't follow the slug instructions explicitly because I just hydraulically deprimed and polished all of my brass so none of the dimensions could be trusted.
Recap
My chamber mold is corrupt
The boolits as cast are .002" too small
The Lee crimp is dragging off the driving bands
The gas check is resizing the brass making the fit loose
Any other lessons for the day?
I have always said that I buy my education $20 at a time but this is a little crazy.

[geargnasher]

Well there ya go!

Let me spend some more of your money.

First, you said "throat" was .342" per ball gauge, I assume you meant "chamber neck". If your brass is .0105" x 2 that's .021 off your .342", plus another .001" off for clearance, leaving a possible boolit diameter of .320". Even if the chamber is .340 and brass .011", you could still safely chamber and fire .317" boolits. Soooooooo........, .314" boolits (throat size) will cause you no problems, and if they have a nose that's .314 about halfway between the case mouth and the tip, they ought to fit the throat better and still chamber fine. So you need two things here: A new mould and a .314" Lee-style push-through sizer die, which to your good fortune Lee actually offeres a .314 sizing die kit as a standard option.

Now you need a good set of reloading dies that will handle .314" boolits. I think the Lee seater die will swage boolits with .314" noses, so you'll possibly need to hone out the roll-crimp ledge with a split dowel rod and some Emery paper. Same for the sizer die, you'll need to hone the neck out until it's only sizing the neck of the brass to about .310" or so on the inside. This will take some doing. Then, you need an expander/belling die that will go with it. A few people will argue with me for some good reasons, but due to the odd size you need I'm going to recommend the Lyman 31R "M" expander die for your needs. It has a .310" spud with short .314" step and then a bellmouth shank, so you can start your .314" boolits in it straight and let the gas check do the rest. If you don't seat the gas check below the neck, it will nestle in it's own little "stop" and resist being pushed deeper into the case by recoil forces in the magazine. This will also offer plenty of neck tension provided your boolits are hard enough. They should be at least 15 bhn, a bit harder will probably be better.

Now, finally, you can get on with finding a boolit that fits your gun. You can have a custom one made to fit your exact specs, but I think you'll have decent luck with the Lee C312-160-2R, #90361 because I think the body diameter carries out fully to the break in the ogive rather than taking a big step down to bore diameter (not groove, bore) right after the front band. It's a tumble-lube design anyway, which will work fine since you like to tumble lube anyway. Even if the mould casts too small, which it might, it's an easy design to lap out, and you can even lap it more at the back than front if you're careful with compound placement and get it tapered just the way you want it. It might shoot just fine as-cast though, and I'd certainly try that first. Put your checks on after lubing by shoving them through the sizer, then give them another coat.

The 160-grain Lee boolit also will offer you another fine advantage, and that is you have a lot more options for crimp grooves since it has all the microgrooves, and you can actually roll-crimp with your seater die (in a separate step from seating, with the seater stem backed out so it doesn't touch the boolit) or you can just use the FCD and crimp it at max OAL for your mag if that doesn't happen to coincide with a microgroove in the boolit body.

Ok, I've spent a little less than $60 of your money plus shipping, and only about 2-3 hours of your time with some oil and sandpaper to fix your sizing die neck, seat die, and get all this stuff set up. Don't mess with the crimp ledge in the seater die unless it's a problem, you'll know if it is if your new boolits won't pass through the die completely with the seating plug removed. Your new mould may not need any attention at all if the boolits it casts are big enough. Most of the Lee moulds I have of recent manufacture don't need any prep besides a good scrub with Bar Keeper's Friend and a toothbrush in HOT water followed by a shot of brake cleaner when dry. And of course some mould lube. Get some Zip lube from Randyrat now that Bullshop is out of business.

Please read this post over and over until you understand what I'm talking about, and why, and PLEASE ask any questions about any part of this you don't understand. Also understand that this is just ONE way to go about getting your dies and boolit to fit the gun, there are plenty of others, but I challenge anyone to find a way to do it as cheaply and simply as the above. I've modified Lee die sets in many calibers to fit my particular guns and boolits with just a little time with a drill, split brass rod, and sandpaper.

Gear

[Tech2]

The multi car collision all came into focus when I measured the gas check and saw the chain reaction that it was causing. Such a simple little part.
I ordered the sizer and the mold.
I have a lathe, is this what I need for an expander
http://i755.photobucket.com/albums/xx196/hansen_acura/expander.jpg

[Tech2]

The Id of my seating die is .3119
The new Id should be something like
.0105*2 brass thickness
+ .314 new boolit dia
-.002 compression fit
=.333 new dia

My sizing die is .3233" at the neck
Should it also be opened up to around .330"

[MBTcustom]

You want the I.D. of your sized brass to be only .001-.002 less than your boolit diameter. Any less, and you will need to run a much harder alloy in order to keep the cases from sizing down the brass. (incidentally, I believe this is a big part of the reason everybody seems to think that harder boolits are better. They just think that the harder boolits are sealing the bore better. Ummm wrong, they are merely surviving the reloader stuffing them into undersized necks a little better!)
Since you have a lathe, you should make yourself an M die to give you exactly what you want on your neck tension.
This may seem like a lot of information, but the base concept is very simple: get an over-sized boolit into the barrel of your rifle, and dont do anything to squish it down to a smaller diameter in the process!
Before you can have an "oversized boolit" you need to know what size that is. Once you figure that out, simply make sure the neck will not change that diameter. Or the crimp. Or the seating die. Or the gas check. Or the chamber. Or Bob down the street. Or.......................

[popper]

Increase your OD's by .002, you can always make it smaller. You don't want to decap, size and expand in the same operation. Decap and size with a FL die and then expand. Round the corner of the step, 312-314, brass won't form square corners. The M die has a hard stop at the top, not bell. I think a slight bell or straight is better so you don't crush the shoulder if pushed down too far - think untrimmed brass. If you try to make a GC stop like gear stated, make your .312 section a specified length and end with a sharp radii, no pigtails.

[geargnasher]

I think you'd be better off just buying the M die, I don't know what die body you're planning to use for that expander if you make one, but it won't work in your sizing die very well. You'd have to size/decap all your brass, then swap out the decapper pin for your expander, back the die way up in the press and use it that way just to hold the expander.

The concept is to use your sizing die to make the ID of the case neck about .002-3" smaller than your boolit, and use an expander to bring it back up to the right size and add a little bellmouth to start the boolit more easily. Your sizer die needs to bring the brass just under final size to make up for variances in brass thickness, and using the expander after sizing ensures consistent case neck tension with varying lots of brass. The problem with the setup you have now is you have no bellmouth tool, and your dies are overworking the brass and leaving the case neck too small for the boolit size you need.

To determine how much to hone your die, you can measure it, or do what I do and just size a piece of brass with the decapper out and see how much too small it is, then hone on it some, clean out the grit, and size another case, that way you can see what it's really doing as far as case springback goes. You'll need to use fired or expanded brass for your sizing, otherwise the brass you've already sized won't even touch the enlarged die neck. Somewhere around .330" is probably where you'll end up, give or take a couple thousandths.

Gear

[Tech2]

I didn't find dimensions for the M die but I did find pictures.
No bell just two steps and a lead angle .
revised drawing
The dimensions don't take spring-back into account.
http://i755.photobucket.com/albums/xx196/hansen_acura/expander2.jpg
Is the .314" step equivalent to the bell?
If I can hand seat the sized gas check into the .314 pocket alignment should be good.

[MBTcustom]

Yes, the second step works in place of the belling feature on a normal die. If your boolits are .314 in diameter, you want the nose of the die to be .3120-.3125 and the step up to be .3142-.315. Of course what that means practically is .0015-.002 press fit in the neck and a tight slip fit in the step. I like to be able to press my boolits into the neck of the brass with my fingers and hear a "poonk" sound if I pull the boolit out. You don't want that lead-in step to be much longer than your gas check height.

[Tech2]

Good news to report.
The mold showed up today and it looks good.
I also turned a mandrel today so that I can get just the right case neck dimensions once the new sizer shows up. It may work fine as is or I may use it as a guide for a specific sizer.
http://i755.photobucket.com/albums/xx196/hansen_acura/caseexpander-1.jpg

[MikeS]

I didn't find dimensions for the M die but I did find pictures.
No bell just two steps and a lead angle .
revised drawing
The dimensions don't take spring-back into account.
http://i755.photobucket.com/albums/xx196/hansen_acura/expander2.jpg
Is the .314" step equivalent to the bell?
If I can hand seat the sized gas check into the .314 pocket alignment should be good.

Looking at your drawing makes me think you're misunderstanding the expander concept. When we talk about an expander die specifically for cast boolits, we're talking about a third totally separate die, NOT an expander ball to replace the expander ball on your sizing die. In your drawing the part that's .202 wouldn't be there at all, but instead that part would be threaded with a diameter much larger (maybe 3/8" or so) as the expander is designed to expand the mouth while the case is traveling UP in the die, where a 'normal' FL die for a bottleneck cartridge expands as the case is traveling DOWN in the die.

I would make a drawing for you, but I have absolutely no skill at drawing on a computer! With the 3 die setup, the first die would be your sizing die which would have a decapping pin, and an expander ball. That expander would expand the neck to the size that's proper for jacketed bullets, then the next step is the expander die that will expand the neck more so that cast boolits can be seated without damaging them. This die also will usually expand the last little bit of the case neck slightly larger than boolit diameter (maybe the last 1/8" or so) so you can place a cast boolit into the mouth enough for it to sit there on it's own fairly straight in the case. And of course the seating die will seat the boolit, and for cast boolits it should be setup to NOT crimp the boolit in place, if your cartridge/gun needs the boolits crimped in place, that should be done as a separate operation with yet another die. That last die that crimps the boolit in place can either be the Lee factory crimp die (the rifle FCD is way different than the pistol Carbide FCD), or a crimp die like one of Redding's profile crimp dies, or just another seating die adjusted to crimp with the seating stem removed. If you're loading these on a single stage press, as a last resort, you can take your seating die and readjust it to crimp after you've finished seating all your boolits, then run them back into the die. I don't really like this last option, as I generally like to setup my dies, and not have to readjust them each time I use them.

I hope this hasn't totally confused you. If you already understood the point I'm trying to make, then I apologize for taking up the time & space of this post!

[geargnasher]

I agree with MikeS, I think you totally missed what we're talking about. That's a pretty decent expander you made there, but if you use it in your sizing die, you will only be able to use the die to hold the rod, and you'll have to back the die out of the press about half an inch or more to make it work. You'll have to size and decap, then swap the decapping/expander rod that came with the die with your expander spud, reset the die depth, and do all your expanding.

This would work extremely well if you purchased a $10 Lee Universal Decapper die and used your expander rod in that, and used the straight decapping rod from the Universal die in your resizing die just to decap and resize.

You should really put about a 45-degree bevel on that step at the top so it will provide a slight bell to the case mouths. You didn't leave a lot of meat there to work with, but there might be barely enough.

So:

Step one: Resize and deprime your brass using your current sizing die and the universal decapper rod instead of the normal expander/decapper it came with.

Step two: Expand your case necks and add a slight bellmouth with your home-made expander spud installed in the Universal Decapping die body.

Step three: Reprime. Or do it between steps two and three, no matter.

Step four: Install powder.

Step five: Seat boolit.

Step six: Apply crimp, either with your FCD or by readjusting your seater die to use the roll-crimp. Only roll-crimp if your cases are uniform in length and the mouths square.

Gear

[Tech2]

I have been paying attention.
The mandrel is not for the sizing die.
It's primary job is to let me carefully open up an undersized case neck and test fit a gas checked boolit so that I know so that I know how big to make the actual secondary expansion mandrel.
http://i755.photobucket.com/albums/xx196/hansen_acura/testmandrel.jpg
I Sharpied the mandrel, installled it in the oversized die and then started expanding and test fitting the boolit.
It looks like the Yugo brass has .003" of spring back.