Sizing Cast Bullets

You are correct. If you want a .311 bullet, you need a mould that is made to cast that kind of bullet. Then you need a corresponding sizer.

A .309 mould might cast an oversized bullet, but I doubt if it will be .311.

Yes, you are correct.

They have to start out bigger before you can make them smaller by sizing.

rc

Thats the way it works for any bullet shape.

Please read this:

http://leeprecision.com/bullet-casting/lube-and-sizing-kit/

rc

I found a .311 G/C mold with a round nose profile. Can I install the gas check by running the bullet - nose first, with the gas check on the base, base on the ram, into the Lee Sizer?

Click to expand...

Yes, but with a caveat.

While lee makes this out to be a flawless operation, it is not.

This method slaps the check onto the bullet when it is supported only by friction in the sizer die, not seats the bullet centered into the check- if that makes any sense.

Sizers which support the bullet nose and seat the bullet into the check while both pieces are mechanically centered have a much lower failure rate.

When I first started applying checks using the lee method, as recommended by RC above, it did work- but the failure rate was about 8% out of the first 200 I did. I got a little better at pre-seating them, but I still had blowouts.

When you shank one, you will know it right away, and it'll happen about midstroke as the improperly seated check is wedged some sort of sideways in the sizer die. Some can be re-seated...some cannot. Some have a mild deformation...some of them are quite major. Two things work against ya on this one : mould lines in the GC shank, and the sprue shear line on the bottom of the bullet.

Gas checks are cheap, and its not the end of the world- just something to be aware of when it happens.

Perfectly pre-seating the bullet into the gas-check by hand on a hard surface helps- but its not 100% either. I'll add that pre-seating the dang things is another time step you can get rid of by having a better sizer.

I prefer the GC application process on the Saeco.

The lyman and rcbs both use a push through method of applying the gas-checks, much like the lee...only backwards.

The ones I've seen for sale and had the opportunity to handle, anyways.

http://www.midwayusa.com/product/756252/saeco-lubri-sizer

See that little flange ? the one on the left side ?

It holds the bottom of the lube sizing die travel pin assembly in place, allowing you to just set the check on the top of the travel pin, and seat the bullet into the check with positive force on both sides of the equation.

Its a little bit slower than bangin 'em through full auto style, I suppose...but the results are significantly better.

And, I like being able to get 1k bullets with 1k checks.... not 967 like my first 1k turned out.

If you want, why not try shooting the bullets as is without a GC? If you are using a pistol powder at a reduced speed, you might not need a GC. If you are trying to reach jacketed velocities, then a GC is needed. OR you can try paper patching. That might take you a year to master, although some folks got it working well on their first try.

I use the Lee sizers and can not really say I have head any issues with failures. Not even with my homemade checks. Give the Lee sizers a chance. they are pretty cheap and you'll porbably like them as well.

When you put the check on the bullet, just make sure you push it on all the way and you should be fine.

I use both Lee sizers and a Lyman 450. I've had no trouble seating GC's on any of my bullets. I think if either the GC or bullet shank was of the wrong diameter it would cause a problem, but if the shank fits in the GC it should crimp on with no problems. I am interested in hearing what other problems(other than the over/undersize check/shank one) I may run into if the OP doesn't mind the hijack.

I size and GC all of my bullets with the Lee set up. One of the few things from Lee I think they got right. Actually most of their casting stuff is quite good.

LeverEvolution 30-30 are supposed to be effective and accurate to 200 yds. 2400 + fps. You will be doing good to get to 2000 fps with cast so expect to be 'lobbing' them to 200, drop will be large.

This method slaps the check onto the bullet when it is supported only by friction in the sizer die

Click to expand...

Well, the check is installed by hand. Then you place the bullet on the seating stem. At this point you have gravity holding the check on the bullet. Or more accurately, gravity is holding the bullet against the check. Then you put the oversized bullet through the sizer. At this point you're mashing the gas check against the bullet with a pretty good amount of force to get the bullet through the sizer. If you do not believe this is so, try pushing the bullet through the sizing die with a pencil, instead of your press. So there's a heck of a lot more than friction holding the gas check on while things are sized and crimped.

not seats the bullet centered into the check- if that makes any sense.

Click to expand...

Doesn't make any sense to me. When you forcefully squeeze an oversized bullet wearing an oversized gas check through a narrower diameter sizing die, how in the world can the gas check NOT be centered?

Perfectly pre-seating the bullet into the gas-check by hand on a hard surface helps- but its not 100% either.

Click to expand...

The seating stem is a hard, flat surface, more or less exactly perpendicular to the axis of the sizing tube. When you push the bullet through, it gets things pretty close to perfect via this geometry + the pressure of pushing the bullet through the sizer. I mean, when the bullet is pushed through the sizer, it's not just a tiny carbide ring. It's a long, tightly fitting tube with a very slight constriction. It centers and straightens the bullet as it goes through. Then the pressure of sizing pushes the gas check hard against the seating stem; and even if the base of the boolit is not straight, the pressure of the die on the oversize gas check, itself, would press the check flat against the seating stem as it goes through. So it's the angle of the seating stem surface that determines how straight the check goes on. No matter how half ass you seat it, or how perfect, the check will end up following the shape of the seating stem. I have never seen a check go on crooked, despite crooked bases/sprue lines. I GC and shoot most of my "blems" with base defects, and if I didn't label the bag, I wouldn't be able to tell them apart once the check is on. The OAL of the blems probably has more variation, but the checks go on straight.

Now, don't get me wrong. I have read plenty of posts where people complain of this problem. There's even a guy on Cast Boolits that invented a slow and complicated gas check seating device to fix this problem (and the mechanical principles it uses seem to be more or less the same ones in effect using the Lee sizing dies, except I suppose you're taking that tiny bit of ram slop out of the equation - and then likely losing this marginally more perfect alignment when you size the bullet, anyway). I am not sure if it's the level of straightness that I'm overlooking, because I don't measure my gas checks with a micrometer. Or if the inventor maybe never used a Lee sizer, properly. I'm really curious why his invention needed inventing. If it's the level of straightness down to the fraction of a mic that accuracy hounds are after, I wonder that the chamber pressures don't alter the gas check shape/angle just a little when the round lights off, anyway. I'd think the check would be fire-formed to the base of the bullet. Or maybe this problem of crooked checks is much worse - obvious, even to the naked eye. But it only occurs when the gas check shank is too big for the check or when the bullet is really short and stubby, so I've never seen it?

I'll add that pre-seating the dang things is another time step you can get rid of by having a better sizer.

Click to expand...

Are you saying you can just drop the bullet and gas check into a "better sizer" and it automatically seats the check for you? I assumed you have to at least have the gas check on the shank before the sizing, using any method. I'd be interesting in hearing how this works.

I'm not trying to be argumentative. I'm genuinely curious what these better sizers do better. Apart from the Star lubesizer, which has obvious advantages and receives universal praise.... despite pushing the bullet and check through the sizing die nose first, just like the Lee.

I run my 06 to 2150 fps with no leading with a lee 170 gr FNGC, 31 gr of XMP 5744, and a gas check with no leading. Darn accurate, too. I use Lee liquid Alox for the lube. The alloy is air cooled wheel weights with a bit of tin. This also expands nicely for hunting. I would start lower, but you can definitely hot rod them.

hungry1,
if you haven't bought a .30 mould and like lee, i'd recommend their tl designed for the 7.62x39. liquid alox-ed, gas-checked and sized .312", it's become my go-to bullet for anything .30; 308, .30-06, 7.5 swiss, 7.5 french, .303 brit, 7.62 mosin, 7.7 jap, etc.

i load 17g of 2400 for 1800fps (chrono'd) for all but the -06...it needs a tad more. all whack rocks in my river out to 400+yds with proper hold-over.

no leading issues with bullets cast to wheel-weight hardness after thousands of rounds.

1800 fps, 170 gr. == 15" drop @ 200. 2200 fps, 170gr. == 30" @ 300. Energy will be ~ 1/2 that at muzzle. Pointy boolits gives ~3" gain over FN. Powders will be different for 308 & 30/30, for better performance.

Are you saying you can just drop the bullet and gas check into a "better sizer" and it automatically seats the check for you?

Click to expand...

Yup, pretty much.

You fold the stop flange in, set the check on the stop, put the bullet on it- and squeeze.

The nose profiled top punch centers the pressure- and seats the check against the now reinforced flat surface.

Flip the flange out, and push it through to lube, and pull it back up.

There it is.

I gotta say I'm be very surprised if that is faster than using a Lee sizer. With all the flipping of the flange and placing the GC in the die taking place of putting the GC on the bullet shank. Not to mention, you then have to take the bullet out when you're done. With a Lee, you just keep on popping more, not unlike a Star lubrisizer. The obvious downside is that the Lee doesn't lube. (Of course, the plus side is tumble lubing is going to save you a lot of time, anyway).

And I'd be even more surprised if those "better sizers" seat checks any straighter.

The nose profiled top punch centers the pressure

Click to expand...

If a nose profiled top punch centered a bullet that well, we wouldn't need to worry about neck concentricity, cuz a fitted seater plug isn't too far removed from a nose profiled top punch. I'd bet on the Lee sizer method over this in a test of GC straightness. Pushing a bullet through a sizing die does wonders for aligning it straight.

Again, I'm not trying to be argumentative. I would just like to be convinced that a better sizer is worth the investment of time and money before trying one. And I'm far from convinced. You have apparently used both, but maybe you're not explaining the benefits clear enough.

The lyman and rcbs both use a push through method of applying the gas-checks, much like the lee...only backwards.

The ones I've seen for sale and had the opportunity to handle, anyways.

Click to expand...

Trying to put the check on like the Lee, only backwards, is not the same at all. There's nothing there to straighten the check. If the base of the bullet has a piece of sprue sticking out, the GC would not necessarily seat flat, no matter how carefully you set it on there to start. The drag on the sizing die will push the check against the sprue, causing it to want to tilt just as it's being sized/crimped - off axis and deformed. Even your Saeco will have some theoretical issues with either straightness or concentricity, depending on if it crimps the check on while it seats, or not, before pushing the bullet base-first through the sizing die. So if you're extrapolating the problems with the Lee system by what you've experienced with the Lyman and RCBS, then you might be jumping to the wrong conclusions. Pushing the bullet through nose-first solves a lot of problems. The Lee sizer crimps on the GC pretty darn close to truly straight/flat, the very definition of concentric, and always tight against the base of the bullet, every time, no matter what the base of the bullet actually looks like.

I gotta say I'm be very surprised if that is faster than using a Lee sizer. With all the flipping of the flange and placing the GC in the die taking place of putting the GC on the bullet shank. Not to mention, you then have to take the bullet out when you're done. With a Lee, you just keep on popping more, not unlike a Star lubrisizer. The obvious downside is that the Lee doesn't lube. (Of course, the plus side is tumble lubing is going to save you a lot of time, anyway).

And I'd be even more surprised if those "better sizers" seat checks any straighter.

Quote:
The nose profiled top punch centers the pressure
If a nose profiled top punch centered a bullet that well, we wouldn't need to worry about neck concentricity, cuz a fitted seater plug isn't too far removed from a nose profiled top punch. I'd bet on the Lee sizer method over this in a test of GC straightness. Pushing a bullet through a sizing die does wonders for aligning it straight.

Again, I'm not trying to be argumentative. I would just like to be convinced that a better sizer is worth the investment of time and money before trying one. And I'm far from convinced. You have apparently used both, but maybe you're not explaining the benefits clear enough.
Quote:
The lyman and rcbs both use a push through method of applying the gas-checks, much like the lee...only backwards.

The ones I've seen for sale and had the opportunity to handle, anyways.
Trying to put the check on like the Lee, only backwards, is not the same at all. There's nothing there to straighten the check. If the base of the bullet has a piece of sprue sticking out, the GC would not necessarily seat flat, no matter how carefully you set it on there to start. The drag on the sizing die will push the check against the sprue, causing it to want to tilt just as it's being sized/crimped - off axis and deformed. Even your Saeco will have some theoretical issues with either straightness or concentricity, depending on if it crimps the check on while it seats, or not, before pushing the bullet base-first through the sizing die. So if you're extrapolating the problems with the Lee system by what you've experienced with the Lyman and RCBS, then you might be jumping to the wrong conclusions. Pushing the bullet through nose-first solves a lot of problems. The Lee sizer crimps on the GC pretty darn close to truly straight/flat, the very definition of concentric, and always tight against the base of the bullet, every time, no matter what the base of the bullet actually looks like.

Click to expand...

Ok.

You ever used one ?