bulletsize

[edwin41]

hello,
i have been working om my handgun mould today , a lyman 170 gr semi wadcutter for my .357 magnum.
with my alloy it leaves me with a bullet around .356 as it drops from my mould .
been looking at the problem for a while , and i came up with the following :
we all have a dremel multitool i think , and with the accesorieset there is a accesorie for the cuttingdiscs , like a little bar , with a screw
in front to thighten a cuttingdisc to it.
i punched out some thick rubberdiscs with a punch , the ones that are used for gasketmaking , and then i cut them with a sharp knife
for a correct height , wich leaves me with a round rubberdisc that will loosly fit the drivingband of my bulletmould.
these discs are cut a little lenghtwise , and i keep them somewhat open with the knife.
with a siccor i cut a small reep of waterproof grindingpaper , like 800 grit , and the end i stick in the cut that i kept open with my knife.
wrap around and glued the end with some superglue.
this leaves me with a great tool to lap out my mould , wich i did , and now the bullets from the mould are a little over .358.
when the mould is kept wet with water , and the tool is rinsed with water a lot to loose the foul it works best .
what has this to do with paperpatching ?
well , nothing of course , but while lapping this mould i got another idea...
when i cast for my paperpatched round i have to size my bullet in two steps for the correct size of 6.5 millimeter.
so , if i can take of metal , like in the first case , i can also add metal i think.
im thinking of a hard metal that can be added with a electrolyse treatment , like hardchrome.
i know of a compagnie here in holland that treats cillinders for engines and claim that they can add to one milimeter of hard material to a metal surface , wich would be great!
the nose of the bullet untouched of course , its a noseriding design , but the body of the bullet smaller due to the chrome layer.
that would leave me with a bullet that i could wrap straight from the mould.
anyone done this allready?

[wmitty]

edwin 41

Can they control the thickness of the chrome plating to the degree that would be necessary to allow reducing the driving band diameter the required amount?

I think I see what you are describing, but I'm having a hard time with chrome plating the inside of a mould. Maybe someone has seen this done. I have seen plasma spray performed on worn centrifugal pump shafts to allow the shaft to be machined and placed back in service, but this was a very high temperature operation and was performed with the shaft turning between centers on a lathe.

[CJR]

Edwin 41,

The classic and well documented way to enlarge bullet moulds is to use a bullet cast in the mould to lap the mould. Typically, the cast bullet is drilled axially in the base and a screw inserted. The lapping bullet is then coated with a lapping compound paste, where you want to enlarge the mould, and the lapping bullet is then turned manually or turned with an electric drill while in the mould. Frequent checking, by casting, is required to measure the improvement in diameter. This procedure also corrects an oval bullet to be more round

Also, handgun bullets as you describe and not considered to be "bore-riders" per se. They have cutting shoulders which cut sharp holes in targets (for scoring purposes) or to allow deep penetration in other materials. The Lyman Keith design is a classic example which has excellent accuracy and incredible penetration capabilities.

Hope this helps.

Best regards,
CJR

[CJR]

Edwin41,

I misread your post. Forget my post. You want to reduce the bullet diameter for PP.

Best regards,

CJR

[edwin41]

thanks for the reaction , cjr.
i will try to open upanother mould with the methode you discribed.

[barrabruce]

I'd personally stick to a sizer myself.

or by the time you get it done and maybe lapped out you maybe better off just getting a mould cut.
sizers seem to work quiet well ...with different alloys and such as well.
even if you are just rubbing of the mould line.

but if you can do it then post some pics and show us how it's done.

[Harter66]

I am currently waiting patiently for a 25 cal group buy at NOE for a bullet to patch to .265-6 for a Win Mag . It will of course run fine in a 257 Roberts checked or PB also. That mould will be in 258 or 260 dia and 120 gr ,heavy for the 25s light in 6.5s .

In aviation chroming is used to reduce cylinder bore wear and increase ring life. That chrome stays in tact and shiny up to 500 degrees, that I've seen personally, and can be used to build a cylinder back to a standard dia. Of course those are 31/2 to 5 inch bores and are allowed spark plug gaps for piston clearance . Ceramic chroming is also available here in the US and is in normal use indestructible.

[edwin41]

i think its just a matter of how precise the layer would be placed.
in bigger things like cillinders and such it would be a lot easier to hone afterwards , so i would first have to find out how rough the layer would be.
now i size my bullets through a homemade sizer , works good , but would it not be nice to skip this step?

[Harter66]

Neither the chrome nor ceramic are honed for dimensions. The coating process for the air cooled will allow a building of .015 (the general over bore allowed) or .075 inches per wall . Granted it is a 4 plus inch bore in most cases. Nitriding is not plating but a surface hardening. I would think that the plating could be done but I think chrome will tend to be thicker than you want nickle might work better as a coating but then there are the heat cycles and it's long-term survival. I wonder if black chrome like impact tool chroming might work but it isn't a field that I have much experience with.

I wonder if you could lap up a light 338 cal mould ? I would expect 1 to drop at .340 maybe a little more. That would start you off about .01 below target size.

[Harter66]

I poked around Mountain molds can cut a 348 cal boolit mold to drop .350 at 170 gr. For just $95 getting it to you would be a little more I expect . I don't know what chroming will cost but it might be a break even or close to it to buy a new custom mould.

[edwin41]

thanks for the replies , gave me a lot to think about.
i wanted to chance the mold because the sizing of the castings took a long time , i sized every bullet in two steps.
what i eventually did was take a good look at the sizing , i polished and altered the sizingdie [homemade] a bit , and found out that
when i lubed the bullets with a gearoil , like a 220 , and more like soaking them , i can size the bullets in one stroke.
thats good enough for me for now.
sizing is done with a press i altered for this purpose , got a picture of this in the 6.5x55 mm thread .

[303Guy]

Edwin41 is wanting to reduce his 6.5 mold for paper patching in his 6.5 Swede.

Is there anyone near you that can cut you a new mold to your specifications, edwin41?

[Dan Cash]

Edwin41, Any competent local machinist can build/cut a push through sizer for you for a nominal sum or about 25% of the cost of a custom mould. Sizing the bullet will be a vast improvement over trying to get a larger mould to shrink.

[edwin41]

well 303 guy , its possible to make another mould , but i like the mould i have , wich is a lyman 140 gr.
dan , the push through sizer you mention i have made a long time ago , pictures of it in the 6.5x55 mm thread.
as mentioned , it works now flawlessly in one stroke , and i think i will keep the setup as it s for now.