Aluminium bullets

[rainwalker]

*mad scientist hat is on*

Seems we've got a few here casting aluminium for their different projects. Took me to thinking about aluminium bullets.

Talking out my ass here maybe but seems like you could do some long/high BC bullets, but with aluminium being 1/4 or less of the weight of copper and lead do some really light recoil loads.

What say you casters?

[Jack V]

Unfortunately you don't understand the whole relationship of mass , velocity , kinetic energy , BC and bullet length determining twist rate.
Imagine how long an aluminium bullet would be to gain similar weight to an existing lead core bullet so the twist rate needed would be massive, velocity would suffer , fouling would be horrible . BC would be horrible and down range velocity would drop like a stone and kinetic energy would not take the skin of a rice custard. The aluminium fouling in the bore would ruin the barrel .
It will not work very well .

[The Brass]

Weight is a contributing factor in BC. It's not just all about length (she said )

Think of it you throw a rock, it goes far because it's heavy - momentum, kinetic energy - with some oomph behind it from the thrower.

Throw a ball of paper the same size and the lack-of-weight isn't an advantage. You can throw it much faster than the rock but as soon as it's left your hand it gets captured and dropped by the air within a few metres.

You'd probably get some blistering velocities from one compared to a copper/lead bullet of the same size, but it would decelerate rapidly.

I don't know what the actual range of say a 180gr .30 calibre bullet would be, but it would be very limited compared to a conventional copper/lead projectile of the same weight/cal.

[jeener]

The aluminium fouling in the bore would ruin the barrel .

Someone would make an aluminium solvent I would think...

[lapp]

This may be of interest to you.

cast Zinc / Aluminium alloy bullets.

[Seik]

Someone would make an aluminium solvent I would think...

Yes but you'd need one that wouldn't take the inside of the barrel with it

[Jack V]

Adding zinc moves them more towards being more like lead alloy not aluminium . Pure Aluminium Used in a pistol bullet , it would have less negatives but still not very effective compared to something with higher mass . You may be able to reduce fouling with a coating system but the bullets will still be very light .

[Chronos]

Adding zinc moves them more towards being more like lead alloy not aluminium . Pure Aluminium Used in a pistol bullet , it would have less negatives but still not very effective compared to something with higher mass . You may be able to reduce fouling with a coating system but the bullets will still be very light .

adding zinc to aluminium makes an aluminium alloy, not a lead alloy


Chronos

i have edited this post

[Jack V]

Not talking about chemical composition , we are talking about specific gravity ( mass) . You are the idiot that can't follow the subject .Another stupid comment by Chronos like Mauser bolts are like Sako bolts

[1290]

never heard of casting Al bullet, for hunting anyway... yes, a lot less dense than lead and copper, the MASS (not strictly correct to refer to weight! they are different ) of the proj would be proportionately less for Al... then theres the hardness issue which would alter the pressure effects (easier/more difficult to engrave / more or less pressure) given that Al is 2x or so the hardness of Lead.... pressure will rise.

Relative density (relative to water at STP)
11.36 Lead, Pb,
2.7 Aluminium, Al
8.96 Copper, Cu,

So Al bullet would require 4.2 times the volume to have the same sectional density as Lead....

Lots of materials have historically been used as bullet 'cores'; aluminium, steel, tungsten even wood and other odd stuff.... it provides cheap filler , alters the properties(penetration, etc) and/or more the centre of mass rearward to alter the stability (tumble in flesh etc)

[Chronos]

Anyhoo, to offer an answer to the OP's question, there would be a few issues.

Firstly aluminium has a high shrinkage rate, so bullets would have to be cast larger than required and then sized in a die like a lube sizer. this shrinkage can be controlled to a point by alloying it with different metals but this would add expense.

Secondly as has already been stated here the bullets would be light for their length but that's not such an issue as they would leave the muzzle faster, helping energy levels and reducing drop

Thirdly you'd have to be careful with velocity because high chamber pressures could deform the soft alloy. this could be partially solved by using copper gas checks like they do on cast lead bullets

Lastly there's one big issue. the outside surface of the cast aluminium bullets would oxidise. aluminium oxide is extremely hard (aluminium oxide is used as an abrasive in industry) and could cause some major barrel wear

lots of these issues could be dealt with in different ways, bullet coatings, alloy hardness, bullet shape and low velocities could make a cast aluminium bullet usable but you'd still have to find out if a particular barrel twist would shoot it and it would take time and money

I reckon if you cast a.30cal aluminium wad cutter with a gas check and made the mould long enough to get the COAL up to 2.800" you kept speeds down below around 1500fp it MAY shoot in a 10" twist barrel but i'll never know cause i'd rather shoot 155gr Nosler CC's at under 40c each LOL

Chronos

[1290]

chronos.... take a step back my friend... Jack said 'like' an alloy.

Now I dont know Jack personally,but I know that he deserves my.. as well as your respect. Without getting too far into the matter, so chill, don't go with the insults. Really not necessary, we all talk s**t, I talk a bit of s**t, even you talk a bit of s**t, thats what make a forum interesting!!

[Noisydad]

I reckon Al would shear off in a barrel much like cast lead pushed to hard. Picture the rifling acting like a wood rasp. Al builds up on machine tool tips quite quickly - even at relatively low surface speeds. Kerosene is the usual lube used when machining this stuff to slow the build up and if used to lube an Al bullet, may result in a "deisel effect" that I'm pretty sure would insert some adrenaline up your day!

[Chronos]

chronos.... take a step back my friend... Jack said 'like' an alloy.

Now I dont know Jack personally,but I know that he deserves my.. as well as your respect. Without getting too far into the matter, so chill, don't go with the insults. Really not necessary, we all talk s**t, I talk a bit of s**t, even you talk a bit of s**t, thats what make a forum interesting!!

Agree,1290, POST EDITED

Chronos

[Oldbloke]

EVERY ONE SHOULD COOL OFF. NAME CALLING JUST MAKES US ALL LOOK IMATURE. THE PUBLIC CAN READ THIS.

[North East]

EVERY ONE SHOULD COOL OFF. NAME CALLING JUST MAKES US ALL LOOK IMATURE. THE PUBLIC CAN READ THIS.

There's are lot of this s**t going around these days. Take a look at the "Omark 44 vs newer rifles" thread.

It's a laugh a minute.

[1290]

Frankly, this forum cant afford to lose 'talent'....love him or hate him, westy added a certain flair around here....and now he's a distant memory...

Jack, dont get the wrong impression, I'm not really nice ..... OK, I am, but dont tell anyone

[Warrigul]

There needs to be some additional work done on the aluminium bullet issue, at least in jackets. I used around 500 aluminium gas checks without any issue at all so the potential is there.

[Oldbloke]

Just to add, al is in some situations explosive. Not sure under this stuation.

[1290]

The hardness of Al, compared to lead wold mean that the sizing would have to be considered, bring the diameter down compared to lead so that the engraving is reduced... to result in a similar resistance to lead. Much like 303 bullets are undersized, by design, to groove diameter....

[Oldbloke]

Silly discussion. Too low a sg to be of real use. Perhaps for the fun or challenge of trying, but thats it.

[rainwalker]

then theres the hardness issue which would alter the pressure effects (easier/more difficult to engrave / more or less pressure) given that Al is 2x or so the hardness of Lead.... pressure will rise.

How about hardness compared to a solid copper projectile?

[Blackened]

this forum cant afford to lose 'talent'...

'talent' is only worth so much grief. Knowing a lot, contributing a lot, doesn't mean you can be an asshole a lot too. Helping one person while berating and insulting two others is not a winning formula.

It's a problem that effects all forums to some extent. More often than you'd like people who contribute more than others think it gives them the right to tote it over other people. They expect complaints about them to be dismissed, and anyone they complain about to be censured or banned immediately. They sling as much as they get then play the victim over the whole incident.

Whether you started an argument, continue in, rise to the bait or only responded doesn't matter. Pick whatever quip you like... "It takes two to tango", "If you're not part of the solution you're part of the problem".... When you're involved in 10 pointless arguments a week derailing every topic you take part in you're definitely part of the problem.

The fact that we're discussing this in an genuine, curious enquiry about casting bullets is proof of this.

The vast majority of members have no dramas here at all. Differences of opinion are discussed or disputed calmly without name calling or ill feelings. A few can't seem to let things drop though and pointless arguments follow them around because of it. A few people have consistently been involved in pointless and damaging arguments here for an extended period of time and enough is enough. "If you're not part of the solution you're part of the problem". Now they're gone.

The later few need to accept that people won't always agree with then and that they don't get the last word on all things. That's how the rest of us get by peacefully and stress free.

You may have caught the reason 'goodbye' topic before it was removed which was nothing but a swearing filled page of abuse directed at half a dozen other members the OP had issue with. There is no excuse for this kind of thing.

We try not to step in too much because we don't want to be dictating conversations or taking sides. We accept people have different points of view and rely on members to do the same. I'm sure you'll have observed 95% of members here have never said a harsh word to another member. There is no reason the other 5% couldn't be the same.

We take no pleasure in banning people but eventually enough is enough. A few have gone, if others 'rise' to take their place they'll go too.

Perhaps we allow things to go on to long and should be taking action sooner. Something for the future...

(This topic comes to mind: How to have a disagreement.)

[Klem]

Perhaps for the fun or challenge of trying, but thats it.

Two good reasons to do anything

[1290]

When I used to term talent... I should have put a few of these in with it


When it comes to baiting, there are a few master-class baiters here The trouble is sometimes its hard to read someones expression when they hit submit, to tell whether their tongue is firmly planted in the cheek...

[Blackened]

The trouble is sometimes its hard to read someones expression when they hit submit, to tell whether their tongue is firmly planted in the cheek...

That's true. In either case it's no reason to fly of the handle as some do.

Anyway... Back to business...

[on_one_wheel]

When I used to term talent... I should have put a few of these in with it


When it comes to baiting, there are a few master-class baiters here The trouble is sometimes its hard to read someones expression when they hit submit, to tell whether their tongue is firmly planted in the cheek...

"master baiter " didnt know you could say that here.

[ghunther]

I see what you did there

[Monty]

When I used to term talent... I should have put a few of these in with it

So... Distinct lack of crazy bastards?

We'll take it as a compliment

[brett1868]

I doubt a %100 cast aluminium projectile will work as so many posters have alluded to already. Maybe if you wanted to lighten a high BC projectile you could use a cast aluminium core to reduce the weight in relation to size. The Hornady 750gr 50cal AMAX projectiles use such a core made from aluminium to keep projectile weight down while achieving a BC of 1.050 with a length over 2". While the cast aluminium projectile may not be feasible, you could use it as the base to custom build a specific length and weight around that will work.