7.62 tracers in .303?

[CastAmerican]

I have just started down the path of reloading for 303 British for my Lee Enfield. I read some stuff about people using .310 7.62x39 bullets to reload 303. I slugged my barrel and it is at .311.
My question is, has anyone used 7.62mm tracers or some other sort of special ammo to reload 303 Brit, and if so, what results did you get?
Thanks.

[Chainsaw.]

In a word, No. 303 British, as you’ve proven with your slugging, is a .311 bore, general rule of thimb with jacketed bullets is 1 thou over bore size, thats .312.
So, those .310 bullets would be “rattling” down your barrel. Will they safely go bang? Probably. But accuracy will be out the window.

[tangolima]

Originally Posted by Chainsaw.

In a word, No. 303 British, as you’ve proven with your slugging, is a .311 bore, general rule of thimb with jacketed bullets is 1 thou over bore size, thats .312.
So, those .310 bullets would be “rattling” down your barrel. Will they safely go bang? Probably. But accuracy will be out the window.

I thought the 0.001"-over rule is for cast bullets.

I wouldn't think 0.001" under is too much an issue for jacketed bullets. Good accuracy has been reported quite often with even 0.308" bullets down 0.311" barrel's.

-TL

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[F. Guffey]

In a word, No. 303 British, as you’ve proven with your slugging, is a .311 bore, general rule of thumb with jacketed bullets is 1 thou over bore size, that's .312.
So, those .310 bullets would be “rattling” down your barrel. Will they safely go bang? Probably. But accuracy will be out the window.

Just ahead of this thread is a thread about ojive, ogive tangents etc. I said the barrel has two diameters, the 308/Cal. diameters are .308" and .300". The 303 is not a one diameter barrel, the other diameter is .303"

And then there is the 8MMM, it has a small diameter of .311" and a large diameter if .323" so there is a very good chance if a bullet is going to rattle down a barrel it will be the 308/30 Cal bullet down an 8MM barrel,

And then there is a good chance the 303 bullet will slid down the 8MM barrel and turn/rotate as it travels.

F. Guffey

[Unclenick]

There was a cadre of British shooters in years past who swore by the accuracy of .309" bores with bullets that were .308". Even jacketed bullets bump up under pressure. I can't recall if our friends from across the pond were still dipping bullets in grease at the time, though.

Most rifles of all kinds under the SAAMI specifications have a range of bullet size that goes from -0.002" to +0.001" groove diameter as standard. So +0.001" may be used with jacketed as well as with lead. Indeed, a lot of 32" Palma Match barrels are made with 0.3065" to 0.3070" groove diameters. I've actually found +0.0015 to +0.0020" over groove to be most accurate with a lot of lead bullets in a number of my guns, so it's good to keep in mind the rules of thumb are just that, and not exact science. I note that a lot of Sierra match bullets are 0.3085" in 30 caliber, so they must have found some advantage to being a little over, even with jackets. But that doesn't mean undersized bullets can't still do pretty well if they are jacketed. You just can't normally undersize lead without getting gas cutting and bad bore fouling that results.

[T. O'Heir]

"...general rule of thumb with jacketed bullets is..." Nope. That's cast bullets only. Either way, the .303 Brit uses .311" bullets. .308" bullets are the wrong diameter, period.
The 7.62 x 39 uses .311" bullets(7.62mm is the nominal bore diameter. That's the size of the hole that got drilled) too. So does the 7.62 x 54R. Not .310". Those'll do though. Even though they're very light(usually 123 or 125 grains). One thou either way won't matter and there is 123/125 grain data for the Brit. Mind you, no range will likely let you shoot trace anyway. There's a perception that tracers start fires. Range grass has to be really dry for that to happen. Most tracers are FMJ's too and a lot of ranges won't let you shoot them either. Too many idiots damaging range equipment with 'em.
"...slugged my barrel and it is..." Having one that slugs at .311" is kind of miraculous. Most are bigger. Up to .315" is considered OK. No jacketed bullets that big though. Montana Bullets makes .311" to .314" cast bullets for not stupid money. Ya know? For when you buy another Lee-Enfield(demand proof of good headspace), slug it and find it's not .311".
Anyway, there are lots of good .311" jacketed bullets made for reloading .303 Brit. You can get away with using the available .312" bullets too. Those are the commonly available diameters. You need to know which manufacturer uses which diameter and pick the bullet. Sierra makes a 174 grain Matchking and 150 and 180 grain Prohunter. Hornady makes a .3105" FMJ just to be annoying.
"...the 8MM, it has a small diameter of .311"..." No it doesn't. The pre1905 M/88 cartridge used .318" bullets with a nominal bore of .311". Post 1905 ammo is .323" bullets. No .311" at all with 8mm Mauser.

[CastAmerican]

Thank you for the responses.
The link is one of the only places I found to buy .311 tracers. They are pulled 7.62x54r bullets and some are quite dirty. The description said that they loaded a few and didn't get the tracer compound to light and instead had a incendiary like effect. Do you think it is the powder mixture? And if it didn't end up lighting correctly, that isn't too bad a deal for just FMJ right?
http://ammunitionstore.com/products/...500pc-can.html
Thanks

[T. O'Heir]

"...pulled 7.62x54r bullets..." Those would do nicely. Correct diameter and everything.
"...think it is the powder mixture..." Nope. The trace element isn't ignited by the burning powder. It's lit by air, it being a phosphorous compound.
However, the trace element compound is easily knocked off the back of the bullet. (That's what is happening when you see film of tracers hitting stuff and there is all kinds of what appears to be riccochets bouncing around. It's not. It's the burning trace element flying around.) That's probably what happened to the bullets that didn't light.
"...a incendiary like effect..." The only affect incendiaries(that are illegal in most places) have is starting fires. Tracers do not start fires. Unless the grass is really dry. Nor does hitting hard stuff "set off the tracer compound." It's not percussive.
An FMJ hitting a metal target frame can cause a spark. You know? metal hitting metal. Highly unlikely to start a fire though. Unless the grass is really dry. It's also why a lot of ranges don't allow FMJ's or trace and absolutely no incendiaries.

[Unclenick]

Originally Posted by T. O'Heir

Nope. The trace element isn't ignited by the burning powder. It's lit by air, it being a phosphorous compound.

Nope! There's been no phosphorous in tracer rounds for a long time. They are currently made of compounds of strontium and magnesium and barium. Basically, it's a road flare compound that is lit by the cartridge propellant charge flame. If you don't believe it, watch this video.

Phosphorous used to be used in tracers and in incendiary rounds, however, the manufacturing handling and safety difficulties have seen magnesium compounds mostly replace them. But even the old ones with phosphorous were specific compounds designed also to be lit by the propellant charge or by a priming mix that goes off on the bullet's impact with the target, as ignition by air would have the air in the cartridge case lighting them, if they ever got there and weren't exposed to air during manufacturing and loading. The kinds that are lit by the propellant flame used to be called "smoke tracers" because of the smoke trail visible in daylight from their burning phosphorous compounds.