Throat or bore

Hello All.

Just a quickie, when using GC's do you size the bullet/GC to throat dia or bore dia.

Thanks E/T

Size them to what you size your bullets to. IE. If you size to throat, size them to throat. If you size the .002 over grove then size them to that. Ext..

If you want use them as cast run them through a sizer small enough to crimp the check, but large enough it doesn't size the bullet.

Thanks Rc, Im using as cast for 303Brit at the moment 0.314" they shoot quite well but need a bit more oooph. Again Thanky kindley. E/T

Thank you Matey. Im loading for 303Brit at 0.314, they shoot quite well but need a bit more oooph. Ill try the GC's

Thanky kindly E/T

I usually try them from bore size up to throat size in rifles, kind of depends on how long the throat is. Usually sizing to the throat has worked best for me, even if the bullet is smaller (GC bigger than bullet). My M28/76 is a good example of that liking an unsized .310" NOE 311331 with the GC crimped on with a .311" die. Throat is a long one at .311" but the bore is only about .3085".

Good advice above. I do something similar for my 91-30. My mould drops just over .313" so I use a .314" push through die to crimp the gas check. It has always worked well.

Well not always the gas check diameter was marginal but I set up the mold and bored them a couple thousands larger. :)

Motor

Size bullet/GC to throat diameter. Exception being some MN chamber throats won't allow that.

Ok sounds good ,,,,,,,,,,, "MN" ?????

MN = Moisin-Nagant.

Expect some wartime .303 "trench chambers" may have throats larger than max. gascheck diameter also, but if bullet "fits" otherwise, at higher velocities you will get better results with the GC than without it. It may take some experimentation to see how large a push-through sizer you can use and still crimp the GC on the heel of the bullet.

My CBE mold from Australia has a large GC heel and I am able to crimp Hornady GCs on at .315" diameter. My NOE #314299 will also, but GC heel on older Lyman mold is too small to do so.

Not sure which powders you have available in UK but I use 30 grs. of Alliant RL7 with #314299 for about 2000 fps from my Long Branch No.4 and it shoots more accurately than Greek HXP MkVII back to 600 yards.

Im sizing on a Lyman 450 so can set the depth to just crimp the G/C. Im casting from a Lee 185g that throws 0.314" and seating into the lands just enough to mark the nose. This bullet has quite a deep heel for the G/C I was wondering if anyone makes a deep G/C about 0.125 would be just the job