The UK's Finest Independent Forum for Shooters and Gun Owners. Est 2010.

What size bullet are you guys casting for the .310 Cadet?

Depends on the chamber and bore size.

My current one shoots a 0.316" body with a 0.308" heel delivering the legendary 310 Cadet accuracy.

I have had them as big as needing a 0.324" body diameter bullet.

As always bullet fit is king so take a chamber/lead/bore cast and then you will know what bullet the rifle will need rather than speculating on that which fits anything other than your gun.

Groove diameters of .316 are something of a legend in the 310 cadet shooting fraternity. I have never come across one, and I have slugged a lot over the years for fellow club members. Every one that I have measured has been .320. My RCBS mould casts out at .322". If you slug my rifle and then attempt to measure the diameter by rotating the slug in a vernier caliper, you get around .316".
It is eary to measure the diameter of a slug from a barrel with an odd number of grooves if you have access to a lathe. Chuck up a piece of scrap metal and drill an undersized hole in it. Then, with a boring bar, gradually open up the hole until the slug will just slide into it. Then measure the diameter of the hole.

Fred

The trick is to measure the diameter just in front of the case mouth and before the rifling starts, the freebore. No need to worry about odd groove numbers, although I use a "V" block to measure them.

Getting the bullet to just sit in the freebore keeping it centred means that you don't need to worry about the groove size although my current Cadet measures 0.316" both for freebore and groove diameters.

In all the many Cadets I have had the RCBS mould has always been too big for a good chambering, many a time this has been because of the oversize heel needing the case expanding before it will seat and this case mouth diameter being to great to chamber. Lovely mould the RCBS but I don't know why I still have mine as I haven't used it in decades.

The RCBS mold is the only one I have Im afraid.
hmm whats next.

A good impact cast of the freebore and rifling.

dromia wrote:A good impact cast of the freebore and rifling.

Yes, that does make sense. But only having the RCBS mold Im not sure its going to help.
I don't shoot it that often. In fact the boolits I'm using of which there are very few left I got from you. They are from one of your molds.
You gave me a box full for free to try after purchasing a firearm in your establishment if I remember rightly. Many moons ago.

Accurate do my 310 cadet bullet and Tom will cut to your size both for body and heel at no extra cost.