5 Groove Enfield

[DonH]

.303 guys, could you share your method of determining groove diameter in the 5 groove barrels?

[oneokie]

There is a V-block available for using to measure the diameter of odd shaped cylinders.

Another method is to wrap the boolit with shim stock and measure as you would a round object, then subtract 2x the shim thickness (if only one wrap is/was used).

[Larry Gibson]

A thin strip of aluminum pop can 1/2 x 3" will do nicely instead of shim stock. That's what I use and it works fin. Another with the 5 groove Enfields is to pin measure the bore and add .011" to that (based on manufacturing specs of the barrels). While not exact to the .0001 degree both methods are close enough for figuring out cast bullet size. Then slug or make a chamber/throat casting and size the bullets to the throat size which is the more important measurement of the two.

Larry Gibson

[wallenba]

I use the shim trick. My fingers fumble a lot, and I usually don't trust what I see. Then I do it over and over until I'm sure. I often wish someone made something like a drill bit gage. A plate with known diameter holes in the ranges found in S&W's and other fivers. A go, no go type of tool. I think I could sell a bunch here.

[JeffinNZ]

I don't bother. Shoot the fattest bullet that will chamber and you're in business. 5 groove barrels are pretty good on specs. A .314-.316 bullet will do OK.

[longbow]

WhatJeffinNZ said.

I slugged my throat and size to suit the throat. In my case with 4 Lee Enfields they all run about 0.314" groove and 0.315"+ throats and all like a 0.315" boolit.

It works for me.

Longbow

[BruceB]

Just for information's sake, yesterday I cast about 400 of NOE's 316299 bullets in clip-on wheelweight alloy.

Measuring one of the bullets a moment ago, I find that the nose measures .305", and the bands are .315"..... just about perfect for the .303 rifles that live with me. It weighs 209.2 grains.

I've yet to do any serious experimenting, but it sure does look like the proper basic material is here.

[longbow]

That's the same mould I have BruceB and those boolits shoot well from my .303's. They cast about 0.3155" and I size to 0.315" so the sizing die is hardly touching lead but crimps the gas check just fine. They chamber and shoot well.

I think you will enjoy that NOE mould and the boolits it casts.

Longbow