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Is there a rule of thumb about how far you can reduce a cast boolits diameter. I am trying to develop a cast load for my 7.62x39 AIA for short range out to 25 yards at present. I have tried several different boolits and deduced that a long boolit with lots of lube grooves works best. The standard Lee offering and soup cans don't perform very well. I am limited to the amount of molds I own. Any way to get to the point I have a mold that is for the 8mm mauser its a heavy boolit its got lots of lube grooves. Can I size it down to .311 and use it. I thought to do it in a couple of passes through my lyman lubrisizer reducing the boolit diameter by a small amount each pass. Will it work or will the boolit groove diameters end up to small to hold lube. I will be tumbling them in allox as well of course.
Iv seen a mold on the NOE web site that I think would be ideal but they are in the States so I am not going to be able to get hold of one of them in a hurry.

I use 0.313 sized boolits in my AIA.
Squeezing 323 ish down to 313 is a push and you may end up with no lube grooves.
I use an NOE mould that is spire point gas checked and has one lube plus the gas check gap which holds lube.
Its about 135gn all up.
Shoots well in my 303 as well.
Tony

Do you know the NOE mold reference number of the mold you use.

Its this one:

http://noebulletmolds.com/smf/index.php ... 276.0.html

Alpha1 wrote:Is there a rule of thumb about how far you can reduce a cast boolits diameter. I am trying to develop a cast load for my 7.62x39 AIA for short range out to 25 yards at present. I have tried several different boolits and deduced that a long boolit with lots of lube grooves works best. The standard Lee offering and soup cans don't perform very well. I am limited to the amount of molds I own. Any way to get to the point I have a mold that is for the 8mm mauser its a heavy boolit its got lots of lube grooves. Can I size it down to .311 and use it. I thought to do it in a couple of passes through my lyman lubrisizer reducing the boolit diameter by a small amount each pass. Will it work or will the boolit groove diameters end up to small to hold lube. I will be tumbling them in allox as well of course.
Iv seen a mold on the NOE web site that I think would be ideal but they are in the States so I am not going to be able to get hold of one of them in a hurry.

I size the Lee 175gn .323 8mm Mauser bullet down to .314 in one pass through a Lee bullet sizing die for my SMLE with no problems.
I lube with Lee Liquid Alox before I size and again afterwards.

Have you tried the Lee 160gn .312 7.62x39 bullet mould No.90361, or the Lee 155gn .312 bullet mould No.90385?

If you don't get good results with .311 bullets, I suggest you slug the bore to get a better idea of optimum bullet diameter.
ukrifleman.

I have both of the Lee moulds I'm thinking about trying some thing like this one.
http://noebulletmolds.com/NV/product_in ... ucts_id=80
I will have a go at sizing the 8mm boolit I have down to .314 and see how it goes.

I just read a interesting post on cast boolits .com the guy sizes 8mm cast boolits down to .314 regularly. So it can be done. There was also a interesting post about how a guy modified a Lee push through cast boolit sizing die to convert into a bushing die. A interesting concept the only draw back is the fact I would have to use it in a press I prefer to neck size using a arbor press. Just shows you what people will turn there hand to though in pursuit of their hobby. tesnews

Its this one:

http://noebulletmolds.com/smf/index.php ... 276.0.html

I checked the mould out yep its a .314 as well. I think the answer is a .314 Loverin. But we will see Iv been rummaging in my boxes Iv got a few moulds. I think I have lost some somewhere as well I thought I had more but maybe not. Loads of gas checks though and sizing dies and quite a few top punches. I think the stick of lube in the lubsizer has seen better days think that's going to have to be dumped and a new one sourced. Oh and a set of 11mm Mauser sizing dies. There are other dies as well but I'm not interested in them at the moment. This AIA is flavour of the moth at present.

Yes you can size down cast boolits quiet substantial amounts but like everything it has consequences.

It is best to size down in 2 thou steps as this means you aren't straining the sizing equipment. Even then it is better to use a push through die on the press, not an arbor though. Many people make push through dies however I prefer to use the H&I dies from my lube sizer as I have them already in many bespoke sizes and it save duplication with dedicated push throughs, You can just use them as push throughs on the sizer however if you want to use a press then Keith theperfessor makes a nifty piece of kit for holding the H&I die and collecting the boolits along with calibre push rods, he is currently taking orders on Cast Boolits for another run. http://castboolits.gunloads.com/showthr ... -sizer-set

If you don't want to go for Keth's fine kit then if you take the gubbins out of a Lee collet die, put it in the press upside down the the H&I die will fit into the body just dandy, you will need to fashion or get a suitable push through rod though.

Also lube grooves will get shallower and could disappear, standard practice is to put the boolit through an as cast sizer first to lube the grooves as this helps stop the boolit from deforming too much in the process.

As the lead has to go somewhere then the boolit will get longer the more you size it so this could effect seating depth.

To be honest with all the bespoke and semi bespoke mould makers out there getting a mould that will cast your chosen design and specification is so easy that that is route I would go and not bugger about sizing boolits down more than a couple of thou.

I'm going to go with what I have for now. Iv got some moulds and lots of sizing dies so we will see. I'm going to have a bit of a play. Once I am happy and know exactly what I want I may order a mould. I quite fancy the NEI one I looked at but its out of stock. I don't know whether they just do group buy runs or if its a stock item. I don't know how the business works Iv never dealt with them. The other problem is all the mould makers are abroad. As far as I am aware no body does moulds in the UK.