Sizing advice, oh gurus of cast boolits!

[sniper]

I have a Lee .358 sizing die, and after running Speer lead balls through it, find that they measure .3575 .

Measuring sized wheelweight bullets, the body is .3575, and the gas check is ~
.358. I presume there is some "memory" to the gas check, and probably the alloy.

Is this close enough for government work and reloading, or should I buy another die, and hope I win the lottery this time? Lee says the variation in dies could be +- .0005, and mine is " in spec". Does the variation+- make a difference in the real cast boolit world?

Or, as an alternative, should I try try to open it up a bit, hoping I don't go through the surface hardening, which Lee says is .010 deep?

What do you experts think?

[cbrick]

sniper, what your post didn't say is what diameter boolits do you need?

The alloy will have an effect on the final sized diameter of any bullet sized in the same die. Another way to say it, size different alloys in the same die and you'll get different final sized diameters. This is not a fault of the die, just a fact of life of different alloys. If a larger diameter than your WW .3575" is needed as cheap as Lee dies are why not just get a .359" die?

Rick

[9.3X62AL]

Generally, the harder a lead alloy is--the more "spring-back" it will retain after sizing. Unalloyed lead seems to be a "dead metal" when sized, but you can pick up ~.0002" of diameter at each step by using WW--Taracorp--Linotype alloys in that order.

Opening up a die is always an option, and a "little too big" is USUALLY better than "a little too small" in the cast boolit game. If Lee does not offer a .359" die, perhaps Buckshot can cobble one up for you.

[GabbyM]

Simply check a sized bullet in your cylinder throats. As long as you feel stiff resistance to pushing them through you should be good to go. If they are loose you can easily hone out the Lee die until the bullets tighten up. If the .3575 bullet won't push through the throat their's not much sense in making it bigger just to swag down upon firing.

[mtgrs737]

I was worried that my Star .425" sizing die was undersized because the freshly sized boolit measured .4515" right after sizing. Upon measuring the next day the same boolit measured .452" so I suppose the die makers take into account that the alloy used in boolits will spring back a tad over a short period of time.

[DLCTEX]

Removing .0005 from a Lee push through is so easy you'll have to watch it or you'll go larger. Dale

[montana_charlie]

I suppose the die makers take into account that the alloy used in boolits will spring back a tad over a short period of time.
My impression is that the manufacturers size their tools to perform as advertized with the alloy each manufacture call it's 'standard alloy'.

Lyman must believe that everybody uses Lyman #2, because their moulds and sizing dies produce their stated dimensions when that alloy is in use...but you must make adjustments to your thinking when using 30:1.
CM

[AZ-Stew]

It's easy enough to get .0005 error, simply due to measuring technique. This, of course, assumes your measuring device is perfectly calibrated in the first place.

As others have said, if the boolits properly fit the chamber throats in the cylinder of your revolver, the .0005 difference between the marking on the sizer and actual produced size of the boolits won't matter.

Be sure to check all chambers, using a fresh boolit for each one. I checked one of my revolvers a week or so ago and found two chambers that were .001-.002 larger than the others. The boolits should be made to fit the largest chamber throats. Another revolver I own, made by the same company, these boolits, as cast, fit perfectly in all six chamber throats.

My latest .44 mould throws boolits that measure (according to MY micrometer, yours might give a bit different measure) .431. The largest sizer die I have for my Lyman lube/sizer is marked .430. The boolits enter with no resistance and come out with very light burnishing marks at various locations around the driving bands. This leads me to believe the die is actually .431-.4315. Doesn't matter. I 'm more interested in the lube function than I am the sizing function for this boolit.

Regards,

Stew

[GabbyM]

I've a Lyman size die here that's marked .430. It sizes to .4312". Can't use them as gages for sure. lol
Luckily I did'nt own a .431 yet so I simply ordered an RCBS .430" die.

[sniper]

I'm not sure I fully understand the relationship of bullet and cylinder throat size. IIRC, they should be a bit larger than bore size?

As Pogo used to say; Whuffo?

I mean, we are shooting soft(er) lead projectiles, which should conform themselves through obturation and the forces of firing. The old boys didn't know all the stuff we do now, but they seemed to do just fine. Just thinking to myself, here.

Anyway, iirc, my throat diameters are the same or just a tad larger than my sized bullets. I'll have to look it up, if I can remember where I put the measurements. That will happen after the housefull of grandmoppets leaves sometime later.

I love the lights of Paris, I love the lights of Rome, but the lights I love the best are the taillights of grandkids going home! :mrgreen:

Maybe I will try the sizer lottery again.

Thanks for the suggestions.

[Dale53]

"The old boys", like Elmer Keith gave the same information regarding bullet fit in the cylinder throats in the year of his first book (1936). Some of the "old boys" not only had it correct, it is still correct, today.

Bullets significantly smaller than the throats will tend to gas cut, the major cause of leading. This is aggravated by "too hard" bullets.

A reasonable alloy for the purpose (most pistols and revolvers do well with Wheel weights + 2% tin) with a decent lubricant will shoot most accurately when sized to the cylinder throats. It IS important for the cylinder throats to be slightly larger than the barrel dimensions (.001-.002" is desirable).

Dale53

[miestro_jerry]

I go .001 to .003 over the "bullet size" depending on what the bullets is for and the that certain rifle or pistol. I use Lyman #2 alloy most of the time, some bullets are made from 50 lbs of WW with 1 pound of Tin, for very high speed rifle loads, I use lino. I mainly use a Star sizer and have lots of dies, then my RCBS which is getting some more use for certain bullets these days and the Lee Sizer system for my Ranch Dog bullets.

Jerry

[Larry Gibson]

Agree with Dale53, that's how I do it based on what the old timers said. If I can't size to cylinder throat size then "as cast" with the soft WW + 2% tin Dale mentions works well. The cylinder throat fit is the most accurate though.

Larry Gibson

[GabbyM]

Sniper: What I was referring to was.
A bullet larger than throat diameter will be swagged down to throat size as it passes through. A little swag is good. Since we need some tolerance to work with and undersized will , as stated, cause gas cutting. From what I've hear you can go oversize up to the point where bullets will chamber. I've never personally had to deal with that.

Since you've an undersized die you have the opportunity to fit your bullet to your cylinder. Chances are you won't need to do anything. You do want your boolits to be bore diameter or larger when they hit the forcing cone. Which is why gunsmiths ream undersized throats up to bore diameter or a bit over.

Btw. You take the memory out of those gas checks by annealing them. Do that buy placing them in an old cast iron skillet and cooking them until they turn blue.