Oversize bullets from the mold

[Unertl]

Hello all

I recently picked up a mold with the intent to paper patch up to size.(.277) The mold was made for a early 6.5mm/264 cartridge, named after the bore size, 256 Newton.

I have a habit of using chamber cast alloy to see the boolet without firing up the smelter. Despite the mold being labeled '268' it dropped at .275. I expected some amount of oversize from the mold but is this amount common? The mold is pristine, to the point of wondering if it's ever been used. The mold is a Modern Bond 268-718/875, I cast the 75gr. cavity not the 100gr.

Is sizing down to the .270 bore size possible without distorting the shape of the boolet?
Jeff

[MT Gianni]

Isn't the 270 a 0.277" bore? I would beagle it and shoot it as is. You might try sizing to .270" and paper patch with the thinnest paper you can get. Distortion would depend on your alloy.

[1eyedjack]

256 Newton and modern bond date back about a century ago ! I have an OLD modern bond wad cutter 38 mold that drops at about 360 very good quality and very old .it's easier to size a bullet down than to add a bit to it.

[Hannibal]

There's not a good answer to be had until you try one of 2 things.

Load a few rounds and shoot them.

Slug your bore and see what you've got.

Either way, the bore condition and the target will tell you if you're doing good or have work to do.

[Delkal]

I have a habit of using chamber cast alloy to see the boolet without firing up the smelter.

Bad habit. Cast an actual bullet and let us know that happens.

Also give the mold faces a good inspection for bits of stuck lead.

[20:1]

Cast several a sample with your intended alloy. You'll find that the alloy used, and the mould temperature have a big effect on bullet diameter. Cerrosafe in a cold mould isn't going to give you much usable information. Also, cerrosafe changes diameter at different times during its cooling cycle so your dimensions will vary depending on at which point you measured it.

[Unertl]

I've got a couple of busy weeks/weekends coming up, but I will make time to cast a batch of the these.

[gwpercle]

Cast with boolit alloy ... slug your bore ... size to bore ...

And ... Choot 'EM... Unertl ... Choot 'Em !
Gary