Bullets over weigh and oversized

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Last Post 14 December 2009

Standard Member

drew212 posted this 08 November 2009

I recently cast my first 200-300 .401 175gn bullets and only about 150 of them were keepers. I weighed all them and they weigh around 180-182 gns. And they measure from .405” to .406". Lee claims that many of their micro band bullets dont need resizing but after sizing, you can hardly tell they're a microband bullet, as the sizing die smashes the bands very close together. Is it common to have bullets that weigh this much over, and are .004” to .005” inches too large? Also, is .406” a small enough to reload without resizing?

Also, I'm pretty sure some of the WWs I cast were zinc, even though I was careful to quickly pull out WWs that floated and WWs that were marked with a Zn or Z anywhere on them. How can you tell if you have zinc in your ingots and in your bullets? Most of my ingots look “fine", although I have no clue what fine really is, lol. Is it easy to skim out the zinc by keeping your alloy temp below 650 or so?

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corerf posted this 08 November 2009

That is your tru bore diameter? If you slug your bore, add .003 to that dimension, thats a good start to the bullet diameter. If your using a 401 die to size for a 401 bore (industry spec) but you have not measured your bore, your probably sizing them too small. You probably need 405 diameter based on a bore slug dimension.

using 309 as example, usually you need 311 for bullet diameter, not 309. Sometiimes if bore wear and throat wear is bad, 312, 313. Normally, 310 will be too small for all but the tightest barrels.

Zn WW are “typically marked” Zn. If anything floated (wheel weight), it was bd and needed to be gotten rid of. Dos the alloy cast ok? Does it fill out the ingot mold nicely? If no then your ok. Zn is a problem you will find with absolute certainty if your normally filling out good mold stops doing so and bullets have spongy exterior.

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Duane Mellenbruch posted this 08 November 2009

corerf wrote: That is your tru bore diameter? If you slug your bore, add .003 to that dimension, thats a good start to the bullet diameter. I believe that corerf may have inadvertantly used the term bore diameter instead of the groove diameter. The bore diameter is the smallest measurement of the barrel and the groove diameter is the largest measurement of the barrel. The Throat diameter is larger most times than the groove, but not always so. That is why it is best to slug the barrel to determine the bore and groove. This question seemed to be about handgun bullet fit, not rifle bullet fit. You may wish to clarify that question. Duane

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drew212 posted this 08 November 2009

The problem is the lee sizing dies don't offer anything outside the popular caliber sizes. The next size up they offer from .401 is .410. I would like to buy a lubrisizer, but I don't want to shell out another $200 plus dies. Right now I'm trying to keep my bullet casting supplies as cheap as possible, I'm not shooting any matches so I don't need perfect bullets.

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corerf posted this 08 November 2009

Thanks for the correction Duane, that is what I meant. I was trying to make a generalization regarding bullet to groove diameter, regardless of rifle or pistol. The bullet needs to be over groove size no matter what (well theres another generalization, a broad one). Merely stating that the bullet need to be bigger than saami barrel dimensions, usually... regardless of throat,etc. I made early on the mistake of using a lee 358 die for my TL bullets. Ooops big time. I needed 3595 or 360+. I didn't get that till I TL'd with LLA as-cast (lapped the mold to get that diameter cause Mr. Lee undercut the mold too), then loaded and what a difference. There is the odd fat fat fat bullet that wont chamber but 99% of them slide in for a friction throat fit.

You could open the lee sizer up by hand. Worst case is it's too big. Really cant hurt it much. Use a drill, some oil and 320 grit paper. Make a split mandrel from a dowel, etc and slide some 320 in. Oil the die and paper. Let the drill rip for a bit. Polish with 600 or 1000 grit or finer but if your polishing it, stop early. Push a bullet thru and measure it with a mic. Go as big as you want. It may take a little bit of trial and error but it's cheaper than other options. you can save up for a 4500 or equivalent and get the dies exact as you want. Sand paper and oil is pretty cheap. As cast is free, if they will chamber and shoot. Usually (my experience), the throat wont let them in if they are too big, regardless of seating depth.

Dont bother to size. If your using lee sizer are you doing the lee lube also?? Have you tried to shoot your as-cast bullets just LLA'd?? That works pretty good with modest pressures.

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Dicko posted this 09 November 2009

Anything over one quarter percent zinc makes the alloy pretty much uncastable. At one percent it would be useless. You'd see it in incomplete fill out, rounded corners etc. No amount of increase in casting temperature helps. So if your bullets did not exhibit those faults you are OK.

Moulds vary slightly so you could cast from ten identical moulds and get ten different bullet weights. That's because of normal manufacturing tolerances and to be fair to manufacturers moulds seldom vary more than two grains either way. The worst I had was four grains out but that was an exception.

Bigger variance is caused by the alloy. Antimony is lighter than lead, so more antimony = harder bullet = lighter bullet. But not as much as 7 grains. I suspect your alloy is a bit softer than ideal but you also have a mould with cavities a bit on the generous side. I wouldn't worry about it. Doesn't really matter whether a bullet is 175 or 180 as long as they are consistent, and I suspect that if you make them as hard as they should be ( 6% antimony ) your weight will come down a grain or two.

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drew212 posted this 10 November 2009

What are commercial cast bullets for 40 S&W sized to? What if I'm reloading for more than one gun?

I'll post pics of a few bullets I cast sometime soon. I didn't have any filling out problems, but there are some specific areas of “frost” and the corners aren't as “sharp” as I would expect them to be.

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CB posted this 10 November 2009

I cast commercial 40 cal bullets and I size to .401. A 40 cal bullet (jacketed) is .400 I have fellows reporting back that they shoot well without leading and I cast most pistols bullets at 10 to 12 bhn.. Of course if you are casting for yourself the best way is to slug your barrel and then use the groove diameter + .0005 then size to slightly over groove diameter like about a couple of tenths. You want to make sure you completely fill the groove diameter with the bullet so the hot gases from the powder burn cant escape past the bullet base.

As for the areas of frost, I wouldnt worry about that. I suspect that the mold isnt “broken in” all the way and that is the cause of the non sharp corners. Clean the mold well with a toothbrush and a degreaser. There may be a bit of oil in the corners. Lee uses a cherry to cut all of their molds and I am sure they make the cherry a bit on the large side so they can get many cuts before the tool is worn out. When you are saying 'microband' do you mean tumble lube?? I have a 40 cal lee 175 truncated cone 6 cavity mold I use, but it has a single lube groove and I was just wondering what the term microband means.

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hunterspistol posted this 10 November 2009

Hi Drew,

The best way to determine a lot of these measurements is to invest in a 6” dial caliper. A lot of molds say they are for a particular caliber but, pour oversized. In a 175 grain bullet, you're weight variance might be around 1.5 to 2 grains. If you go too far toward match accuracy, you don't get to shoot a lot! As for sizing, I started out sizing a .311 barrel to strictly .311 but, sometimes a .314 sizing die gets me my best accuracy. Using recovered bullets is the best slug measurement that's handy somedays but, not always possible.

If your sizing die smears the bands on the bullet, you're usually getting too small with an oversized bullet. As far as alloy goes, the only time I had mine swing badly, I was adding linotype (they lighten dramatically). Back to straight wheelweight. If your cast bullet is .405 to .406 then try sizing the middle ground .403 or .404. A .403 bullet would be great for a .401 barrel, supposedly.

Ron

PS: you haven't mentioned flux, parafin or beeswax works to burn off the stuff that surfaces, after you skim it clean, re-flux and stir, then pour. Jeff made a very good point with degreasing the mold. I've went so far as to use 409 kitchen cleaner to degrease some of mine, dry with rubbing alcohol and smoke or soot the mold a little. hth

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Johnny Breedlove posted this 14 November 2009

Jeff Bowles wrote: I cast commercial 40 cal bullets and I size to .401. A 40 cal bullet (jacketed) is .400 I have fellows reporting back that they shoot well without leading and I cast most pistols bullets at 10 to 12 bhn.. Of course if you are casting for yourself the best way is to slug your barrel and then use the groove diameter + .0005 then size to slightly over groove diameter like about a couple of tenths. You want to make sure you completely fill the groove diameter with the bullet so the hot gases from the powder burn cant escape past the bullet base.

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Standard Member

Dicko posted this 16 November 2009

Hi Drew,

Like Jeff Bowles I also cast commercially. I size all my bullets one thou over groove. For the 40S&W thats 401. Bur some guns shoot as well with groove dia bullets as with one thou bigger. Sizing one thou bigger than groove makes sense in commercial casting because being slightly on the fat side will be more accurate in most guns without ant pressure problems because cast bullets are comparatively soft and squeeze down to size in the barrel easily. But note the jacketed bullets are groove dia, ie 400 for the 40 S&W.

If you are shooting two guns the same calibre why would that be a question ? Sioze 'em all 401. Unless of course you want to slug the barrels. Then, when you know the exact groove dia you can size the bullets to suit, or one thou bigger depending on what range tests tell you what works best.

Frosting and incomplete fill out are contradictory. Frosting is too hot and incomplete fill out is usually too cool. But you can get both at the same time. Big calibre cavities can leave a thin web of metal between cavities. Especially with Lyman two cavity which are quite small blocks to start with. I have some which even at 600F overheat that thin web so that the bullets are frosted at that point and the frosting cause incomplete fill out. I have one RCBS 44 Mag mould and a Lyman 454 x 325 grain Casull mould that have to be used as single cavity moulds because of that phenomenon. But I have cast fro both cavities of an identical RCBS 44 Mag mould with no trouble, which proves that moulds can behave differently.

I agree with Jeff about cleaning the mould. They leave the factory with a film of protective oil. If you don't clean it off it can burn into a hard crusty deposit that will make good casting impossible and will be difficult to clean off. Nothing fancy is needed. Just clean them with turps ot thinners. The whole mould not just the cavities.

I also agree with getting a dial caliper. That is I agree with the principle but not the choice of instrument. Dial calipers are very useful and versatile because they can measure outside, inside, length and depth. But for various reasons they are not quite as accurate as a micrometer. Every handloader should have a good one inch micrometer. Probably less expensive than a dial caliper. With the change you can buy an inexpensive vernier caliper which is a dial caliper without the expensive dial. But hey, I'm not putting down dial calipers, thay are very nice tools to have, but you'll do better with a mike and a vernier.

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CBA Member

JetMech posted this 16 November 2009

Dicko wrote: I also agree with getting a dial caliper. That is I agree with the principle but not the choice of instrument. Dial calipers are very useful and versatile because they can measure outside, inside, length and depth. But for various reasons they are not quite as accurate as a micrometer. Every handloader should have a good one inch micrometer. Probably less expensive than a dial caliper. With the change you can buy an inexpensive vernier caliper which is a dial caliper without the expensive dial. But hey, I'm not putting down dial calipers, thay are very nice tools to have, but you'll do better with a mike and a vernier. While it's true that a caliper is not as accurate as a micrometer, even the cheap, $20 made-in-China dial calipers are accurate to .0005". They are marked in .001graduations and the accuracy level is as stated. I run a calibration program and the cheaper sets we have are as accurate as the Fowlers and Starretts. Micrometers, with a vernier scale, are marked to .0001, and are accurate to half that. I have several sets of calipers and mics, but the vast majority of the time, the calipers work just fine. The mic gets the nod when measuring pressure rings on cases. Measuring bullet diameters, the mic comes out occasionally to verify what I'm reading on the calipers, but for most handloading, I think the calipers would be the first precision measurement tool I would buy. They give you much greater capabilities to perform precision measurements. Then, I'd buy a micrometer. Just my $.02.

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m113103 posted this 10 December 2009

If your bullets are coming out oversize your alloy is too hard. Add some pure lead. Most molds are for a #2 mix andd WW are harder than this. Check out the Lyman cast bullet handbook on bullet mixes and bullet diameter.

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CBA Member

Duane Mellenbruch posted this 10 December 2009

m113103 wrote: If your bullets are coming out oversize your alloy is too hard. Add some pure lead. Most molds are for a #2 mix andd WW are harder than this. Check out the Lyman cast bullet handbook on bullet mixes and bullet diameter.

RCBS molds uses 1-10 (tin-lead) as their standard, NOT Lyman #2.

Lyman #2 , at 15 BHN is harder than WW which can be about anywhere from 9 BHN (.5 tin-4 antimony- 95.5) from another cast bullet list, up to 14.5 BHN from Handloader magazine #183 and had a make up of approximately 1 tin-9 antimony-90 lead. Duane

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CB posted this 10 December 2009

When I need a Lee type of sizer that's in an odd diameter, I buy the nearest under sized kit to the one I need. Then with “sandpaper” and a cotter pin, I lap the hole out to the size that I want. Go VERY SLOW and check often when doing this, when you are near the final diameter, change to a ultra fine emery paper. You can fine the ultra fine emery paper in most department stores automotive sections.

Jerry

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Dicko posted this 14 December 2009

Dollar Bill wrote: While it's true that a caliper is not as accurate as a micrometer, even the cheap, $20 made-in-China dial calipers are accurate to .0005". They are marked in .001graduations and the accuracy level is as stated. I run a calibration program and the cheaper sets we have are as accurate as the Fowlers and Starretts. Micrometers, with a vernier scale, are marked to .0001, and are accurate to half that. I have several sets of calipers and mics, but the vast majority of the time, the calipers work just fine. The mic gets the nod when measuring pressure rings on cases. Measuring bullet diameters, the mic comes out occasionally to verify what I'm reading on the calipers, but for most handloading, I think the calipers would be the first precision measurement tool I would buy. They give you much greater capabilities to perform precision measurements. Then, I'd buy a micrometer. Just my $.02. Sometimes one has to write too much in order to explain a point satisfactorily. I use a cheap chinese vernier for the vast majority of my measurements. I agree that they are as accurate as the big name brands. My point about vernier calipers is not that they are mechanically inaccurate, but that they are harder to read. Often it takes some care to see which line is lined up, and that gets worse as eyesight deteriorates with age. They also need good “feel” to avoid some spring in the jaws that is easy to get with only light pressure. So it is a matter of operator inaccuracy because of the way they work. I agree that is is slight and that a vernier caliper is OK for most measurements to do with handloading. But some things need a mike, as you have indeed said. Many handloaders do their own gunsmithing and toolmaking. That needs a mike. So I accept Bill's point but stick to my recommendation that no handloader should be without a mike. If my info from machining magazines is correct, mikes and verniers are so cheap in the US that there's no reason not to have both.

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Bullets over weigh and oversized

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