2 vs 3 vs 4 cavity mold? Accuracy is my goal.

I have very little experience in casting rifle bullets. Actually, only the Lyman design #311041 years back. Now I'm looking for a new adventure using a different .30 caliber mold. My #311041 was from long ago on a group buy here on the board and made by LEE, a 6 cavity mold. I realize I could use it instead of buying a new mold, but where's the fun in that? :) I want a pointy boolet (something new to play with).

Reasoning tells me a 2 cavity mold would be less likely to have much variance between casts. I'm aware that alloy hardness, twist rate, velocity, lube, etc. all play a part in the making of a great load. A 1.5" group at a 100 yards would be more than sufficient for my intent, having fun and maybe some hog busting.

Thoughts and input anyone?


Murphy

You are correct!

I think which bullet you try is way more important than how many cavities. I don't have hardly any experience with rifle bullets but a ton with pistol and design is by far the most important aspect with accuracy. Now to figure out which to buy cause I really have no idea. I would research as many places as I could.

Quote:

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Originally Posted by Murphy

Thoughts and input anyone?
Murphy

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A "thought and input" or two, or three :) I might offer is my having and using up-to-10 cavity moulds (.38 S&W Special) forty-fifty years ago... NOW, I enjoy using only one and two-cavity moulds... The more cavities = more weight! Added, I have gotten into the "habit" of using two moulds in one casting session, alternating them which provides great timing. Lastly -- I truly believe the quality of bullets cast using one or , two-cavity moulds overall is as efficient as using multi-cavity moulds. As a note, I "devised" using a stack of free-laminate-flooring sample pieces under my bottom-pour pots to enable sliding the multi-cavity moulds, too. NOT necessary with the one- and/or two-cavity moulds. Also, as stated, I use bottom pour pots; I would imagine (???) the weight issue might even be more pronounced with ladle-pourers?
geo

I exclusively use 2 cavity Lyman molds, with a few single cavities having been converted to HP. You didn't specify what caliber you are going to be loading these boolits into - since you've already been down the 311041 road (which was designed exclusively for the 30WCF (30-30Win)) Perhaps the next mold you should consider is the 311291. It is the other one that normally comes to mind when picturing the 30-30 and cast boolits. I'm just getting into Rifle cast reloading/shooting as well, but my limited experience indicates that both the 311291 and 31141 are proven designs that just plain work.

Murph, for handgun bullets I have 2, 4 and 6 cavity molds. Honestly, I like the 4 and 6 cavity best. For rifle, the most I have is two cavity and I ladle pour them. I require greater accuracy out of my rifles than handguns. With all my double cavity rifle molds the weight between the two cavities is almost always less than 1/2 a grain, if not identical, when everything is up to temp. That's close enough for me. Maybe I've been fortunate with the molds. It stands to reason that occasionally one will get out that doesn't throw bullets that close.

As far as a 30 cal. mold, I am clueless as I don't have anything 30 cal. I have molds all around it but no 30.

Serious rifle cast boolit match shooters use single cavity nose pour molds, a gentleman named Eagan was known for his single cavity brass molds.
I have a couple of his 22 caliber and one 30 caliber cherries.
I made one 30 caliber mold and sold it to a member here but I have not gotten to make the 22 caliber ones yet.

Back in the 40's and 50's, single cavity molds were preferred due to dimensional differences in mold cavities from multi cavity molds. I understand that the BPCR crowd still largely follow this practice. However, modern mold manufacturers using CNC machining can make multi-cavity molds with cavities as near as to identical as it is possible to measure. If you are ordering an Accurate, NOE, MP or other 21st century builder, I doubt you'll see a difference.

What I have done, with older, 2 cavity, Lyman Molds, is separate the boolits from each cavity and size, lube and seat gas checks on each pile individually. I haven't rigorously tested, but my impression is that there may be a minuscule difference in group size with really accurate rifles. But for my use, it's not worth the effort.

Those big bore black powder long range shooters who are shooting for prizes , money , blood and bragging rights ... swear by a single cavity mould .
I find it easier to get perfectly cast consistent boolits by pressure casting with a Lyman Ladle and favor 2 and 3 cavity moulds ... but I'm not a serious competitor shooting for prize money or glory .

Take your 6 cavity mould and check it out ... cast some boolits and see how consistent they are . Pressure cast with pot and ladle ... you might find casting the first two ( or three) cavities will give you consistent boolits . You have the mould , try different casting techniques and see what cavities are consistent . Just because a mould has 6 cavities ... you don't have to use all 6 of them if you are looking for accuracy .
Gary

All my rifle moulds are Accurate AL 2 hole. Not just weight but good pours. Don't have trouble with dimensions but alloy/mould/sprue plate temp is easier to control. I still use rnfp, <2 moa @ 200 from my AR10 carbine. The Lee 155 does got good reports for a Lee mould.

I would say single or mark your cavities and segregate bullets by hole and then go by weight , use what you have or order the single nose pour as it in theory is the one going to have the least base defects .

Some of my larger rifles have only single cavity , others I have had custom molds cut with 2-3 cavities , bullets that are off weight can be used for shorter range or plinking .

You can’t go wrong starting with a two cavity mold.

Murphy,

For absolute accuracy with my rifle bullets cast for Schuetzen I use a single cavity mould and keep the bullets that emerge in the order cast, shooting them in that order. The idea is to eliminate as many variables as possible.

For pistol and revolver bullets, my level of accuracy both for the arm and for the nut on the butt (me) is nowhere near as high, so I prefer to gain some speed using 2-4 cavity moulds as available. I find at my age there is a limit to how much fun I can stand casting with multi-cavity iron moulds, so I am gravitating toward 2 or 3 cavity moulds. This is me and my experience. YMMV!

Froggie

Murphy-- I am fortunate to have one of those 6 cav Lee clones of the Lyman 311041 that I bought from a board member here and I m happy to report that it casts boolits that are very uniform cavity to cavity. I and a buddy use that boolit in CBA competition and he gets better groups than I do, often less than 1 inch, yet I cast all the boolits for him!!����

I cast 85-90% for rifle and I agree with Shuz..

I only cast one pointy bullet - the 311299, and it is a tack driver in my Finnish Mosin.
Attachment 292140

There is a reason the old target shooters wanted one hole molds. They also marked them to index in their rifles.
I see very little if any difference in between the bullets from multi cavity molds from NOE, Accurate and MiHec.

I don't think the number of cavities is as important as the quality of machining and the machinist. There is no reason that with today's modern machinery that identical multiple cavities can not be cut.
I don't think in a quality mold that the number of cavities is the limiting factor. Besides you could buy a multiple cavity mold and cast in one cavity and determine if it makes a difference versus multi-cavity casts.

I use 1cav or 2cav molds. Just prefer it that way.
It's what My Dad prefered, and that was back in the day when You could get any mold number in any number of cavities from Lyman or H&G as long as You were willing to pay for it. And the old Man could afford it.

If you are looking for 1.5" at 100 yards you are likely working with a .308 or .30/06...right? (might be helpful to share the cartridge you are working with) Look at the .30 XCB threads posted by Larry Gibson and Tim Malcom. IIRC they got very good results and they worked with multicavity molds.

What folks did decades ago may not be gospel today. Technology has made some progress...LOL.

Also, are you looking for plinking loads or hunting loads...velocity matters.

Here is a taste:
https://noebulletmolds.com/smf/index.php?topic=533.0