Cast rifle bullets swaging down.

[Reefinmike]

:banghead: Im at a loss, Im doing everything right, but no matter what way I do it, my bullets are being squeezed down about .0025 once they are seated in the case.

Bullet is the 230gr lee bullet for the 300blk. the mold drops pure clip on wheel weights at .308. I do a tumble coat of powder coating, size them to .309 and do a second powder coat for a final diameter of .3105 give or take .0005. these are water dropped when casting as well as water dropped after they are out of the oven and not sticky anymore.

Brass: I am using only converted lc brass to keep things consistent while working out this problem

Dies- Rcbs sb 300 blackout die set with both the original expander ball(.306") as well an additional larger one rcbs shipped me(.308") I am using a 30 carbine powder through expander in a 357 die body to charge cases with my autodisk as well as a slight case flare to aid in loading cast.

Problem:

Using the larger .308" expander ball, neck springs back with an inner diameter of .307". I seat a bullet measuring .3105" using only enough "crimp" to iron out any belling of the case. When I pull these bullets, they come out .3075-308". 2-3 thousandths smaller than before it went in

If I size the bullet to 309 and use the smaller .306" expander ball, I get the same results, bullets squeezed down to .3065"

If I size a bullet to 309 and use the larger .308 expander ball, there is very little neck tension and bullets push in with ease

I'm at a complete loss. I don't have any issues with any of my handgun bullets swaging down and for those, I use a much softer alloy. typically 50% dead soft lead and 50% clip on ww's with no quenching.

Im starting to build up quite a pile of these pulled bullets in my scrap can

Maybe this is all stemming from the fact that my bullet mold drops bullets a hair small at .308?

annealing is a little much for me, but maybe I need to make one of those fancy annealing machines to soften the necks up?

 

[rcmodel]

You can anneal case necks with a pro pain torch and a pan of water.

You don't need a 'machine' to figure out if it helps or not.

My first thought is, your seating die 'might' be a little tight in the neck department!!!

Color a case with a magic-marker, seat the bullet, and see what rubs off where.

rc

 

[Reefinmike]

Rc- I had the same thought, did the marker test and got no results.

harder lead alloy would be a pretty obvious solution, but Im simply baffled by this. Like I mentioned, pistol loads with real soft lead didnt experience any deformation in their respective cases

I will certainly get out a pan of water and the torch to see if annealing is a solution.

I have shot these and they shoot very well. over 9.2gr of w296, they are more accurate than I am.

(devils advocate) but they work, why not just shut up and move on?

one layer of powder coat gives somewhat inconsistent diameter leading to few neck tension issues. two layers of PC work but is also time consuming. sure I could send the bullet mold in to lee, beagle the mold or polish the cavities larger, but Id still think my bullets would be squeezed down another .002-.003"

 

[243winxb]

If using this bullet, i would guess its easly compressed by the case neck. Add more alloy high in antimony for hardness and larger diameter air cooled. For oven heat treating/water drop, you need a minimum of 2% antimony in the alloy. This may take up to 2 weeks to fully harden. lyman >

Q: Is there anything I can do to make the bullets harder?
A: Cast bullets can be heat treated to increase their hardness providing your alloy has some antimony present. To heat treat your bullets: Cast your bullets in the normal manner, saving several scrap bullets. Size your bullets but do not lubricate them. Place several scrap bullets on a pan in your oven at 450 degrees and increase the temperature until the bullets start to melt or slump. Be sure to use an accurate oven thermometer and a pan that will not be used again for food. Once the bullets start to melt or slump, back off the temperature about 5 to 10 degrees and slide in your first batch of good bullets. Leave these in the oven for a half hour. Remove the bullets from the oven and plunge them into cool water. Allow them to cool thoroughly. When you are ready to lubricate, install a sizing die .001" larger than the one used to initially size them. This will prevent the sides of the bullets from work-softening from contact with the sizing die. Next apply gas checks if required and lubricate. These are now ready for loading.

Bullet Sizes & Weights – How to Vary Them
The bullet diameters and weights presented in this list are based on the use of Taracorp’s Lawrence Magnum bullet alloy (2% tin, 6% antimony, 1/4% arsenic, 91.75% lead).

Bullet diameters and weights will vary considerably depending on the lead casting alloy used. This variation can be as much as 1/2% on the diameter, and 8% on the weight among the most commonly used casting alloys. For example, a .358-158 grain bullet might show a diameter variation of .002", and a 13 grain difference in weight.

Of the most commonly used alloys, wheel weights (.5% tin, 4% antimony, 95% lead) will produce bullets having the smallest diameter and heaviest weight, with such bullets running approximately 1/3% smaller in diameter and 3% heavier than bullets cast with Taracorp's metal. Linotype will produce bullets with the largest diameter and lightest weights. This alloy will produce bullets approximately 1/10% larger and 3% lighter than Taracorp. Other alloys of tin and antimony, with antimony content above 5%, will produce bullets with diameters and weights falling between those cast f rom wheel weights and linotype.

Alloys containing little or no antimony will cast considerably smaller than wheel weights and in some cases will produce bullets too small for adequate sizing.

Within the limitations given above, the weight and diameter of a cast bullet can be adjusted by varying the
alloy’s antimony content.

The size and weight of bullets of a given alloy will also vary according to casting temperature. Higher temperatures will result in greater shrinkage as the bullet cools, thereby producing a slightly smaller and lighter bullet than one cast of the same alloy at a lower temperature.

 

[243winxb]

http://www.lymanproducts.com/lyman/dies/RifleNeckExpDies.phpA Lyman "M" die may help? They expand & open the case mouth.

 

[Reefinmike]

http://www.lymanproducts.com/lyman/dies/RifleNeckExpDies.phpA Lyman "M" die may help? They expand & open the case mouth.

Im already using a larger expander ball along with a powder through flare die for seating larger cast bullets. besides the whole step vs flair thing, I believe my setup closely mimics what you are shooting for with a M type die(expanded case neck with mouth further expanded for seating lead bullets).

edit: I only flair the case mouth out about .003. just enough to not scrape the powder coat off.

 

[243winxb]

To much taper crimp could size the bullet in the case. Brass springs back more than lead, leaving the bullet loose in the case. Sizing down about .005" will do it. But I cant see it sizing the whole bearing surface of the bullet.

 

[Reefinmike]

To much taper crimp could size the bullet in the case. Brass springs back more than lead, leaving the bullet loose in the case. Sizing down about .005" will do it. But I cant see it sizing the whole bearing surface of the bullet.

No real crimp here to speak of, the crimp on my die is set to just barely kiss the mouth and knock it down about .001" to keep it the same size as the rest of the neck (~331").

I just loaded and pulled a bullet in a "notoriously thin" Remington case with the same results. pulled bullet came out .308

I have a few years of experience and great success shooting lead cast pistol ammo. I haven't bought a bullet in years(besides a few boxes of xtp's to keep in my mags). I'm not sure why I'm getting so much trouble with loading 300 blackout but I have certainly learned a lot taking on this task.

Annealing is starting to look like my only out in this situation. I dont want to if I dont have to, but I'm running out of ideas here.

Adding tin/ant is certainly an option as well as heat treating bullets but are my very last option because of the additional cost and heat treating is a whole other world I dont want to get into. Any idea if baking powder coated bullets will kill any hardness gained from heat treating?

 

[rcmodel]

Heat treating or water dropping lead bullets only last so long.
And not very long at that.

They will return to the natural alloy hardness over a short period of time in storage.

Not worth fooling with IMO.

rc

 

[GLOOB]

If I size a bullet to 309 and use the larger .308 expander ball, there is very little neck tension and bullets push in with ease

First off, why would you even try this? If you are upset because your .310 bullets are being swaged down to small, why would you go even smaller to fix that problem?

Second: Are you sure there is very little neck tension? I have a theory that your neck tension is the same, even though these bullets are easier to seat. As you have seen, your brass has about 2 mils of springback. This is what creates neck tension. And you're gonna get that 2 mils whether you expand to 2 mils under or 1 mil under. The only difference is that with the smaller expander your bullets are going to open up the case that extra mil more, which creates more resistance when seating... but if you pull the bullets, the brass is still gonna spring back by about 2 mils under the diameter of the bullet.

A way to test this would be to make a few of these and a few with the .310" bullets. Then pull them down and compare how many whacks it takes.

I have played around with oversize 45ACP and 40SW seater plugs, and I'm finding that if my expander is even a half a mil smaller than the bullet, neck tension is as good as it's gonna get.

Anyway, that is just my 2 cents. For your specific problem, I think you have 2 things going on. First, your blkout brass probably has thick necks, right? If you have the ability to turn the necks thinner, that would help. Second, your bullets are plain wheelweights. My 9mm WW bullets are swaged by 9mm cases, let alone thick blkout brass. So hardening your alloy can help.

But my first thought is to buy a larger expander. Say .310" Try it, and if it's too big, sand it down until it works for your ammo.

My second thoughts is that perhaps when you convert 223 to blkout, the necks need to be annealed, after. In case you haven't seen it, there is a really nifty automated annealer design that is making the rounds on the forums. All I need is an excuse to make one. If only I had your problem.

 

[MEHavey]

BOTTOM LINE:

I have shot these and they shoot very well. over 9.2gr
of W296, they are more accurate than I am.

Obviously, the bullet/hardness/diameter/barrel system doesn't care that the projectile is swaged
down/starts into the leade at 0.308". It bumps itself up properly and goes on its merry way.

I'd light a few candles to Saints Barbara & Maurice and press on.

.

 

[steve4102]

Brass: I am using only converted lc brass to keep things consistent while working out this problem

Did you anneal the necks after they were converted?

Do you have any factory brass to compare with?

My guess is that your converted brass is the issue and needs to be annealed.

 

[243winxb]

Heat Treating of Lead and Lead Alloys

http://castboolits.gunloads.com/showthread.php?61465-Waterdropping-harden-surface-only See posts by Cbrick & links.

I have shot these and they shoot very well. over 9.2gr
of W296, they are more accurate than I am.

Then theres no problem.

 

[Reefinmike]

Well, I got to playing around with the propane torch and annealed a few cases. 2 cases looked fine by me, and the other I got too hot and it started glowing. The over annealed case had very poor neck tension- to the scrap bin. With my two good annealed cases, I seated a .3105" bullet using both the large and small expander ball. Mystery may be solved, bullets pulled from cases using the .308" expander ball came back out at .310". neck tension was sufficient. bullets pulled from cases using the smaller .306 expander ball came out of the case at .309.

gloob- all in the name of science. doesnt hurt to try. and when I say poor neck tension, I mean about 2 pounds of pressure will push the bullet into the case in that scenario. The expander im using measures .308 intended for use with .310 bullets. I would be afraid to go any larger, there would be no neck tension. And yes, I've seen that annealer and have been fascinated by it... i don't want to have to anneal, but it looks like that may be my only choice.

harvey & 243- yes, they shoot great, but i'm trying to address the issue before something goes wrong. I shouldn't have to be using bullets .002 larger than I want their final diameter once they are seated in the case. that's just bad form.

 

[30Cal]

I'd shoot a couple loads and see what you get. If they don't fly well, I'd look at the Lyman M die for 30 carbine. That should get you .310 ID at the neck.

 

[GooseGestapo]

removed by poster

 

[rsrocket1]

I've notice that my PC bullets have way less friction in the brass than tumble lubed or traditional lubed bullets. So much less that unless I sized the neck down to ensure about a 3 mils of tension, the bullets run the risk of being pulled out with just finger tension. In a bolt action gun, that's not a problem unless I unload a round that was chambered. Then the bullet stays in the throat and powder gets spilled everywhere. In an autoloading gun, loose bullets would be a problem. Gas checked PC bullets are not a problem because the friction between the copper GC and brass is still good.

I think you'll need a lot of trial and error playing with wider sized case mouths, even wider sized bullets and adjusting the case mouth so there is enough neck tension to hold the bullet yet the keeping the swaged bullet wide enough to seal the bore.

If it's any consolation, a lot of folks over at Castboolits have given up on that BT 300blk TL mold. Have you tried unsized and tumble lubed bullets with that mold?

 

[Reefinmike]

rocket- I have not yet tried plain old tumble lube as the mold casts bullets at .3075-308", a little small. to be honest, im still working out all the kinks, loading this load/bullet is kinda a gray area and im having to find my own way through. As you stated, pc bullets sure are slick feeling as you load them, you dont get a real good feel of neck tension.

Ive only been pinking empty cans and steel at 25-50 yards and this bullet/load shoots better than the 150gr fmj's I worked up a load for. As stated before, sure, they work and shoot good, but I really feel that I should address this issue of bullets getting squeezed down before I run into an unexpected result due to poor neck tension.

My next direction is annealing. Ive played around with it and its seeming to help.