Cast bullets for the Enfield

Lakemaster wrote: Are there any cast bullet experts out there that have a favorite bullet?...  Anyone have a bullet style that works really well for the Enfield?

The favorite cast bullet is going to be the one that fits nice and snug into the ball seat and lede of your rifle.  Which is also true of every other rifle out there of whatever caliber and make.

You are far less likely to get the best results with the bore riding designs, particularly if it is worn in the ball seat/lede. A more tapered design up until the full diameter at the bands is more likely to reward you with good results.

If you really want to seriously cast, versus just turning out bullets for killing tin cans at close range at a nearby gravel pit, slug the ball seat and lede first so you can measure.  It's nice to know what bore and groove diameters are, but what really counts is whether the bullet sits nice and snug into the ball seat/lede when the loaded round is chambered.  You want the bore obdurated as quickly as possible once the charge fires and the bullet starts moving out of the neck.

A nice rifle deserves nice moulds that will also make both the casting and the shooting far more enjoyable.  I have had nothing but great luck getting Tom at Accurate Moulds to take the measurements I give him and turn out moulds that drop bullets to those exact measurements.

If you are going to powder coat as most are doing these days due to the simplicity and effectiveness, decrease your dimensions by about .002" to compensate for the additional size in diameter of the bullet.

For hunting, bullets with flat meplats are pretty heavily favored by those who hunt with cast bullets.

At hunting velocity the bullet swages down and hits the target sideways. 

I have 50 paper patched bullets ready to try

This is certainly the most interesting gun I've ever tried to cast for in my years

Lakemaster wrote: .320 throat

With cast bullets, whatever type of cast bullet design you're working with, get your bullet to a snug fit inside the ball seat/lede, and that's more than half the battle of load development.  

I believe that is true whether you're obtaining that fit through paper patching (which I've never done for the .303) or by matching through casting techniques.  

Many "beagle" their moulds to get bullets that drop a few thou larger in diameter (no experience doing that), and the easiest way to increase size solves two issues at once: powder coating rather than traditional grease lubes.

Remember that the throat is tapered.  And, the bullet nose also is profiled to a large radius, so it is essentially tapered.  The base of the bullet may be .316 to .318 but it a stuffed into the case neck and nowhere near the throat.  The diameter of the bullet forward of the driving bands will be smaller, perhaps .303 to .304 and not contact the lands in the throat.  But, I agree with your point that you don’t want a jamb condition that would push the bullet further into the case.  And with such a large bullet being used here, that might be part of the problem. 

Some years ago, I discovered that cast bullets can easily be swaged down during the seating process as it enters the case neck. 

I can probably find the Brits' dimensional drawing (or the CIP) for the chamber.  But for many rifles those dimensions are about as theoretical as the dimensions for bore and groove.

You're very unlikely to be swaging lead bullets while chambering.  More likely, you're pressing the bullet into the leading portion of the lands.  Think about the effort it takes to hammer a short lead slug through the bore to get land and groove measurements.

I tried seating the bullet into the lands while attempting to develop loads for CBA benchrest.  Sometimes it just pushed the bullet further down the neck.  Using a hard crimp stopped that but (in my case) groups got worse.  Because now it's a combination of what amount of crimp works best and how close to or into the lands works best.  You end up working with at least two variables at one time.

I saw some guys this worked for who were far superior as load developers and competitors.  Including some for whom if they had to empty their chamber, they knew the bullet would remain stuck in the lands while the case and the powder inside it was extracted.  That setup worked for them well enough that they accepted that and kept a rod handy to tap the bullet out if that happened.

In my opinion, as a general rule, cast or slug the ball seat and lede and measure.  Then work at finding a mould where the bullets fit as closely as possible when the round is chambered.  I haven't done extensive load development, but the bore riding designs like the Loverin styles are far more difficult to get good grouping out of than the more abruptly tapered designs

My thoughts on this (echoing Ken Mollohan who taught me bullet casting for rifles) are that the closest the bullet is to obdurating and sealing the bore prior to the round being fired has numerous advantages.

First, there is minimal bullet travel before the bullet meeting the constriction of the lands and grooves provides resistance and helps with the initialization of obdurating the bore as soon as possible.

Second, the tighter the fit prior to the moment the cartridge is fired, the least likely opportunity for propellant gases to escape around the bottom and sides of the bore, resulting in gas cutting of the bullet and small amounts of lead blown past and ahead of the bullet, leading to fouling the bore and leading.