Using a .310 Projectile in a 303 British

[baffomet]

So I stumbled upon a garage sale and found some reloading supplies. Of the many items available there was one bag that contain about 1,000 of 125 grain .310 projectiles. The elderly gentlemen informed me that he used them all the time with his Enfield Mk4.

I also have SMLE Mk4 so I bought them at a bargain price. I was looking around and found mixed results using them since the diameter should be .312 in some cases .311 worked well.

My question is whether anyone has experience using .310 bullets and where they good or bad in terms of grouping?

Any information would be greatly appreciated.

Thanks!

[thenodnarb]

Proper enfield bullets should actually be more like .313
Hornady makes some SST that are .313 but they are not always available. I finally saw some come available at grafs once and bought a few hundred.
I'd shoot those .310 anyway though. hope you got a good deal. Worst case you might trade them if they don't group well in your tests.

[rm1911]

I got some cast 154gr .311's from hunters supply to shoot out of my 03A3. they work great in it. 10 gr unique or 17gr of trail boss. awesome. accurate and no recoil. (yes you can shoot .310-.311 lead in a 308 barrel. I forgot what the part of the chamber that narrows into the barrel is called, the lede or the cone or something, but if they will fit in the chamber, they will shoot. they do shoot out of my 03A3 but they won't chamber in my marlin x7. so I don't shoot them in that. I have a bunch of 150 fmj 's that I shoot in the marlin with trail boss)

I tried some in my enfield. bad results. keyholed even at 25 yds. they're going to bounce around in the bore. that bullet you have is for 30 carbines. it will shoot out of the enfield, but will be horrible with accuracy.

[CSACANNONEER]

So I stumbled upon a garage sale and found some reloading supplies. Of the many items available there was one bag that contain about 1,000 of 125 grain .310 projectiles. The elderly gentlemen informed me that he used them all the time with his Enfield Mk4.

I also have SMLE Mk4 so I bought them at a bargain price. I was looking around and found mixed results using them since the diameter should be .312 in some cases .311 worked well.

My question is whether anyone has experience using .310 bullets and where they good or bad in terms of grouping?

Any information would be greatly appreciated.

Thanks!

The type of rifle has nothing to do with it. The ID of your exact barrel will dictate what diameter bullets you should use. In this instance, if you want a quick way to check, see if a .310 will drop freely down your bore or not. If it just drops down the bore, it's too small. In this case, I don't think it could be too large though.

[sunborder]

Slug the barrel. Only way to be sure. Jacketed bullets can be 1 or 2 thousands smaller than cast bullets (but never smaller than the bore).

Those .310 bullets are most likely for 7.62x39, as are proper diameter and weight for that cartridge.

[bigedp51]

Below from top to bottom, 1950 unissued Long Branch, 1943 Maltby, 1950 Faz Mk.2, Unissued 1916 Enfield overhauled in 1953, Ishapore 2A1



I shoot Hornady .312, Sierra .311 and .310 bullets all the time, I also shoot .308 30-30 bullets that have a thinner jacket and softer lead core in my Enfield rifles.

I also use 100 grain .312 pistol bullets for fire forming my brass.



When you shoot a flat base bullet and kick the bullet in the seat of the pants, the bullet will enlarge to fill the bore. (obturation)

Depending on bullet construction, jacket thickness, lead hardness, and chamber pressure a rifle bullet can become up to .002 larger and fill the bore.

Bottom line if you have a good barrel with little wear on the rifling and little cordite throat erosion there is a good chance the smaller diameter bullets will shoot well. BUT boat tail bullets and bullets with thicker jackets that do not obturate and fill the bore will key hole.

You will need to try the bullets remembering to keep the chamber pressure above 40,000 psi for the bullets to expand and fill the bore, and see what happens.

On the flip side in older worn barrels a long fat bullet like the Hornady 174 grain round nose or Sierra 180 grain flat base bullets will shoot well.

And don't buy any Russian .310/.311 pulls with steel cores because they will not enlarge when fired.

[bigedp51]

Bullet design and construction means a lot in a worn barrel, I had a old and worn 03-A3 the throat was .312, mid bore was .309 and the muzzle was .312. The only bullet that would shoot well was the Hornady 170 grain 30-30 bullet because it would fill the bore when fired.



The bullet base below the cannelure was .3075



And above the cannelure was .2995



Because the bullet was designed for lower velocities the lead core was softer and it expanded easily to fill the bore.

[bigbossman]

I had great success using the Winchester bulk bullet .310 125gr bullets in my No.4 MkII, but the same bullet in my No.1 MkIII keyholed.

The bore in the No.4 is tighter than the older, more worn No.1.

[Enfield47]

You should slug the bore and see what size it is. Depending on how worn your barrel is, you could use those bullets without any issues but you won't know until you slug it. Here's an easy tutorial on how to do it. http://7.62x54r.net/MosinID/MosinSlug.htm

A problem you might run into is not enough neck tension when seating the bullet. Before you load a batch, make some dummy rounds and see if the bullets stay in place when cycling them through your rifle.

[stilly]

I heard you can do a slight conversion and shoot either .410 outta the 303 or shoot the 303 outta the 410, but I forgot which I heard...

Just sayin.

[baffomet]

Thank you all for the great information!

I'm going to make some test loads and report back. I also want to slug the bore to find out the exact diameter.