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Old 04-18-2019, 08:31 PM   #11
Icelander
 
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Default Re: Iron Content of Rifle Ammo (SS109/M855, M59, M61, M80, M855A1, etc.)

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Originally Posted by a humble lich View Post
Something to consider, are there enough supernatural hunting groups so that iron/steel ammunition might be manufactured? It seems there are at least 3 to 4 well funded groups of monster hunters, in the world and probably more smaller groups that have yet been described. These groups then create a market for iron ammunition which some manufacturer might discover. As some of the monster hunting groups are connected to national governments, they might be able to influence a manufacture to make iron rounds. The manufacturer doesn't need to know why people want iron rounds, and the rounds could be marketed as rounds for reducing toxicity at shooting ranges.
This is in fact exactly my thinking process, more or less in this order, since I started considering it.

I'm planning on having military officers with connections to the Vatican (e.g. former Swiss Guards, Knights of Malta, etc.) having influenced a European ammunition manufacturer so that they make, at the very least, a 5.56x45mm lead-free round made from soft steel. I was considering either the Swiss RUAG or the Italian Fiocchi as the manufacturer.

The Brazilian monster hunters are less connected, but I imagined that they started by hand-loading 7.62x51mm rounds with hand-pulled steel-cored bullets from surplus 7.62x54R ammunition (which is a real thing that people do), moved on to having unit armorers produce such ammunition in higher volume lots in military workshops and then finally convinced the ammunition company CBC to start manufacturing lead-free, steel-core 7.62x51mm ammunition.

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Originally Posted by a humble lich View Post
From my very limited understanding of ballistics, I don't see any obvious problems with iron/steel rounds. As mentioned, you'd probably want to coat them with a softer round to prevent damage to the barrel. The other issue that might come up is iron is harder to work with than lead, so iron rounds could be more expensive.
In the small lots I imagine for the NATO calibers, I expect so. Still, judging by what I could find for actual steel-core ammunition that has been made, it shouldn't add more than a few cents per round.
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Old 04-18-2019, 10:43 PM   #12
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Default Re: Lead-Free, Soft Steel Ammunition for 5.56x45mm or 7.62x51mm

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Originally Posted by Icelander View Post
In GURPS terms, I'm looking for more or less the same Damage as Ball/FMJ lead core bullets, but with the added mystical benefit of being made mostly of steel, for monster hunting goodness.
Such bullets would have inferior long range ballistics due to lower sectional density (which would more than offset the improvement in shape from being longer). However I doubt that would do more, in GURPS terms, than knock 100 yards or so off 1/2D range and 200 or so off Max Range. Not something most monster hunters would care about in these calibres.
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Old 04-19-2019, 07:40 AM   #13
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Default Re: Lead-Free, Soft Steel Ammunition for 5.56x45mm or 7.62x51mm

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Such bullets would have inferior long range ballistics due to lower sectional density (which would more than offset the improvement in shape from being longer). However I doubt that would do more, in GURPS terms, than knock 100 yards or so off 1/2D range and 200 or so off Max Range. Not something most monster hunters would care about in these calibres.
That's true.

For the 7.62x51mm lead-free rounds in Brazil, I imagine that the most skilled armourers for the Army, Navy, Marines and police special forces tried to handload such ammunition so that it would be optimized for 16" to 17.5" barrels of rifles like IMBEL M964 MD1/IMBEL M964 MD3/M964A1 MD1/IMBEL M964A1 MD3/ParaFAL (licensed short-barrelled FALs), the AR10A4 (used by BOPE, CORE and other police special units) or the HK417. That means that long distance performance would not be considered vital.
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Last edited by Icelander; 04-19-2019 at 07:53 AM.
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Old 04-19-2019, 08:15 AM   #14
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Default Re: Iron Content of Rifle Ammo (SS109/M855, M59, M61, M80, M855A1, etc.)

I think that you need some softness in a bullet somewhere, so that it can accommodate to the rifling. The classic copper-jacketed lead has no problem, of course. All-copper bullets are OK, as is steel core, lead layer and steel jacket (the copper wash on those is to prevent corrosion).

Sintered iron is OK at pistol velocities, but needs a jacket of some kind at rifle velocities, and manufacturing that gets interesting.

Jacketed lead bullets are made by drawing the jacket and packing lead wire in under hydraulic pressure. I think steel-core bullets are made by partially packing the jacket with lead wire and then ramming in the steel core under higher hydraulic pressure, so that the lead flows.

To make an all-iron bullet, you could draw a steel jacket, that's straightforward. Then you could pack that with powdered iron, but to sinter that, you need to heat the whole thing red-hot under high pressure, without the jacket warping. That's an industrial process, not a job to do on an armoury bench.

The best method for a high-iron bullet may be a one-piece bullet made from an iron alloy that is ductile enough to deform to rifling. It will still need a copper or nickel wash, or it will corrode really fast. I'll do a bit of research.
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Old 04-19-2019, 08:32 AM   #15
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Default Re: Iron Content of Rifle Ammo (SS109/M855, M59, M61, M80, M855A1, etc.)

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Originally Posted by johndallman View Post
The best method for a high-iron bullet may be a one-piece bullet made from an iron alloy that is ductile enough to deform to rifling. It will still need a copper or nickel wash, or it will corrode really fast. I'll do a bit of research.
Well, that's simple. You just need very pure iron, which is quite soft. The purest industrially produced iron is 99.99% and has a Brinell hardness of 20-30, and pure copper is about 35.

It's still not something you want to cast on an armourer's bench, because its melting point is just over 1500°C. However, an ammunition factory should be able to make such bullets, or they could be turned from iron rods just over 0.3" diameter. In fact, purchases of such rods, in this grade of iron, by security forces, could well be a giveaway that they are making anti-magical ammunition, and is the kind of thing that your PCs' patron's organisation looks out for.
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Old 04-19-2019, 02:22 PM   #16
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Default Re: Iron Content of Rifle Ammo (SS109/M855, M59, M61, M80, M855A1, etc.)

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Originally Posted by johndallman View Post
Well, that's simple. You just need very pure iron, which is quite soft. The purest industrially produced iron is 99.99% and has a Brinell hardness of 20-30, and pure copper is about 35.

It's still not something you want to cast on an armourer's bench, because its melting point is just over 1500°C. However, an ammunition factory should be able to make such bullets, or they could be turned from iron rods just over 0.3" diameter.
If RUAG in Switzerland wanted to make lead-free ammunition in 5.56x45mm that was almost entirely iron, are there iron rods of that thickness around to machine or would they melt iron and cast it in bullet shape?

Also, the SIG SG 550 rifles that the Swiss Army uses have a twist rate of 1:10, which is fine for the specific 62-63 grain GP90 ammunition that they use in Swiss service (and which the Vatican Swiss Guards also use), but might not adequately stabilize longer rounds.

I'm going to have to decide whether the RUAG LFS (Lead-Free Service) rounds are 43 grains and similar length to the GP90 (should be accurate from standard Swiss service rifles) or if they are 50-53 grains and similar in length to Mk262 77 grain SMK bullets (require 1:7 or 1:8 twist rate barrels, which would mean that all Vatican-backed Monster Hunters would use different weapons than those that exist in Vatican armories).

If we assume that in my setting, the crime rates, instability and violence are so much higher than in the real world that it is not considered especially noteworthy that monsignors from the Holy See travel with armed PSCs in Latin America and many other places, should those PSCs (which are clandestinely backed by occult-savvy military men with connections in the Vatican) carry rifles with twist rates more common in the US or should the Vatican anti-monster ammo be designed to work for Swiss Guard rifles?

Keeping in mind that ca iron/mild steel 50-53 grain 5.56x45mm bullets will probably be both more aerodynamic and have better terminal performance than 40-43 grain iron/mild steel bullets.

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Originally Posted by johndallman View Post
In fact, purchases of such rods, in this grade of iron, by security forces, could well be a giveaway that they are making anti-magical ammunition, and is the kind of thing that your PCs' patron's organisation looks out for.
That's a brilliant point.
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Old 04-19-2019, 02:41 PM   #17
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Default Re: Iron Content of Rifle Ammo (SS109/M855, M59, M61, M80, M855A1, etc.)

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Originally Posted by Icelander View Post
If RUAG in Switzerland wanted to make lead-free ammunition in 5.56x45mm that was almost entirely iron, are there iron rods of that thickness around to machine or would they melt iron and cast it in bullet shape?
I suspect they'd order metal of the grade they needed and use extrusion (that's how things like nuts are made), but does it really matter? There's no question that soft iron bullets can be manufactured.
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Old 04-19-2019, 03:47 PM   #18
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Default Iron Content of Rifle Ammo

Easiest way would be to just pull the bullet out of some 7.62x39 Russian rounds and reload them in whatever .30 cal rounds you prefer.

Yes, I know the Soviet-era rounds are .310 diameter rather than .308. If high pressures are a problem swage the projectiles down.
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Old 04-19-2019, 08:13 PM   #19
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Default Re: Iron Content of Rifle Ammo

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Originally Posted by fredtheobviouspseudonym View Post
Easiest way would be to just pull the bullet out of some 7.62x39 Russian rounds and reload them in whatever .30 cal rounds you prefer.

Yes, I know the Soviet-era rounds are .310 diameter rather than .308. If high pressures are a problem swage the projectiles down.
Ah, indeed. I suppose that happens, as 7.62x54R rounds are used for the same purpose.

Swaging it down sounds great.
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Old 04-19-2019, 09:16 PM   #20
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Default Re: Iron Content of Rifle Ammo (SS109/M855, M59, M61, M80, M855A1, etc.)

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Originally Posted by Icelander View Post
If RUAG in Switzerland wanted to make lead-free ammunition in 5.56x45mm that was almost entirely iron, are there iron rods of that thickness around to machine or would they melt iron and cast it in bullet shape?
They'd cold-forge it for bar or rod stock of 1cm or 1/2" or so 'diameter', or possibly from a flat strip that they cut bullet sized bits off.
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