Roto Metals alloy for hollow points recommendation

[chutestrate]

Could anyone recommend an alloy from roto metals for casting hollow points? I'm starting with a .40 and 10mm and a brass mold from mp-molds. I have lots of lead and mystery lead that's great for the range, but I thought for the more serious applications I would use a pure alloy of some type.

thank you in advance.

[dannyd]

You may want to use 1:20 has to be soft to expand

[chutestrate]

Would that 1 be tin or a hardening alloy?

[JonB_in_Glencoe]

I'm curious, what's the serious application?

[Outpost75]

1:20 tin-lead should work fine. In revolvers below 1000 fps I go softer 1:30.

[chutestrate]

Hunting mostly.

[6622729]

Hunting mostly.

Would he need a little more tin for fill out? I'm using straight COWW for a NOE 9mm hollow point and I have to run pretty hot to make sure I fill out. Otherwise it doesn't always fill out around the perimeter of the hollow nose.

[Screwbolts]

Would he need a little more tin for fill out? I'm using straight COWW for a NOE 9mm hollow point and I have to run pretty hot to make sure I fill out. Otherwise it doesn't always fill out around the perimeter of the hollow nose.

IMHO regardless of tin, HP molds need to be run HOT. WW will give perfect fill out when temps are just right HOT.

[chutestrate]

I had someone point out that the pressures of my calibers are high. Could that present a problem? In my uneducated view if the hollow cavity is too large and/or the alloy to brittle or soft then there will be broken pieces or fast expansion limiting penetration. How about the pressures behind the slug? That was why I asked about the alloy. I'm thinking it's not desirable for the alloy to be too soft, but obviously not too hard either. I need to test it obviously and thought if it was slightly hard I could cut it with some pure lead.

[6622729]

Something close to COWW. If yo have lenty of pure I'd get a bar or 2 of superhard from roto and mix what you want. Their Sb alloy % varies too much for me. If you're loading hot for either, harder alloy. AC isocore ~950 fps 165 gr. 40sw TC went through a 150# pig, end to end, don't care about expansion.

Which are you saying varies too much? COWW or Rotometals?

[harley45]

Something close to COWW. If yo have lenty of pure I'd get a bar or 2 of superhard from roto and mix what you want. Their Sb alloy % varies too much for me. If you're loading hot for either, harder alloy. AC isocore ~950 fps 165 gr. 40sw TC went through a 150# pig, end to end, don't care about expansion.

I'm glad you posted this! I have the same mold for my 10MM and have been thinking at 1000 FPS it would are a good pig boolit for Texas hogs!

[6622729]

Actually, both. Roto Sb/Pb is 3-5% (alloy was too variable for top end 308W loads), superhard is 12%. I ingotized the superhard into 40cal 'ingots' to sweeten my alloy when needed.
You could load the 10mm at bottom jacketed load, like the 40sw. I got that pig @ 25 or so yds, fortunately (for me) running away.

Wow. Talk about getting lost in a conversation. We are talking about lead alloys for a boolit. When you mentioned you went through a 150# pig, I read that as you cast up 150# of bullets using an entire "pig" of lead from end to end. At no time did an animal cross my mind! :idea:

[trapper9260]

What would be the ball park idea for the BHN for the hollow point bullet to be then ? If it is COWW is that about BHN of 11 or 12? Or could you go softer?

[gray wolf]

I had someone point out that the pressures of my calibers are high. Could that present a problem? In my uneducated view if the hollow cavity is too large and/or the alloy to brittle or soft then there will be broken pieces or fast expansion limiting penetration. How about the pressures behind the slug? That was why I asked about the alloy. I'm thinking it's not desirable for the alloy to be too soft, but obviously not too hard either. I need to test it obviously and thought if it was slightly hard I could cut it with some pure lead.

I don't think it will be the pressure that will effect the HP, I would think more the velocity on impact.
Yes pressure does in the end = or contribute to velocity.

The HP in A pure lead slug will open up at say--800 F P S may even be effective at 1000 F P S-- but the soft slug will probably lead a tad and skid on the rifling.

I guess what I am struggling to say here is, it's a trade off between speed and BHN
Also how much penetration will be needed.

[fredj338]

My hunting bullets are either 1-20 or 1-25. The 1-20 will be good up to abut 1250fps, depends on the HP design. Above 1100fps, I like shallow cup points, seem to mushroom well & not frag. Below 900fps, a wider/deeper HP will insure low vel expansion. I avoid clip ww for this & just go lead/tin or at worst, range scrap/tin. Too much antimony is where the fragging comes in.

[prs]

I keep hollow points in my 45ACP for two legged critters such as werewolves or zombies. I use 2% tin in almost pure lead (1:50). This is WAY soft, but the velocity is not great. It will lead the barrel if shot much, but in this application one would hope to not need to shoot and even if, not more than twice. But, I do powder coat mine and have shot extended strings of fire at the range with no leading that way.

prs