Enough tin?

[Ole_270]

Mixed up 200 lbs of alloy and sent a sample off to BNE for testing. The alloy is intended for softer plain based bullets under 1500 fps in my 25-20WCF, 38-55 and the 45 ACP. It came back at 0.7%Sn, 1.7%Sb. The Sb is just slightly higher than the common 50/50 + tin alloy so I'm not worried about that. I've never knowingly cast with such a low tin content. I'm pretty sure I can raise the heat level and make it work since it's higher than ww, but wondering how the malebility of the alloy will be effected. I seem to remember Ian saying something about Sb under 2% acting more like a Sn/Pb mix, but with the Sn/Sb matrix being a smaller percentage than the free Sb I'm wondering how it will react. Basically I'm thinking more about the 38-55 at 1400 as a hunting load, and whether the mushroom will hold togeather more than slough off. Any ideas? just getting too worried for nothing?

 

[Brad]

Sounds like what I use all the time. Mine are possibly even lower in tin.
I doubt you have enough antimony in there to give fractures in expansion at 1400.

 

[Ole_270]

Sounds good, thanks. Most will be used in practice and other non hunting uses. The 38-55 will probably get a workout this fall in the timber for some venison to fill the freezer

 

[popper]

I tried 1% Zn & 1% Sn in 40sw, sized too small & leaded but expanded great. Added 1% Sn for 185 gr 30/30, GC and went through pig carcass 30 in 45 out. IIRC 16 gr 2400. Hole was round. I don't normally use any tin, casts fine @ 725.

 

[Ian]

Sounds like a fine alloy to me. The moulds might like to be run a little faster/hotter for complete fillout and it will cast a slightly smaller bullet than coww+2%Sn but functionally the ductile low-tin alloy is fantastic.

Brad and I both have run a similar alloy, water-quenched for toughness, to well over 2500 fps (iirc he got it to 2700 and I hit just over 2600) with 1.5 MOA accuracy in our .30-caliber rifles, so it is a very versatile alloy blend.

 

[Ole_270]

Brad and I both have run a similar alloy, water-quenched for toughness, to well over 2500 fps (iirc he got it to 2700 and I hit just over 2600) with 1.5 MOA accuracy in our .30-caliber rifles, so it is a very versatile alloy blend.

Nice, makes me wonder why I keep the linotype and babbitt around, and why so many insist on shooting the Lyman #2 or harder.

 

[Brad]

Richer alloys do have a place. They just aren’t required for most shooting.
I have over 1000 pounds of range scrap on hand so it gets used far and away the most. I will, at times, add monotype in a 1/20 or 1/10 ratio. That is reserved for times when a harder alloy is warranted.

 

[fiver]

i got lot's of ideas.
try water dropping for the 25-20 and 38-55.
then after about 2 weeks take a couple of the ugly ones set them on the outside stairs or driveway and give them a thump with a 2-4-6lb hammer and see what happens.

 

[Rick]

Nice, makes me wonder why I keep the linotype and babbitt around, and why so many insist on shooting the Lyman #2 or harder.

Commercial casters continually hyping their bullets as "hard cast" has a very detrimental effect on newer casters and buyers of those bullets. Too hard is a primary cause of leading, inaccuracy and frustration among those using "hard cast". I use CWW at 12 BHN for at least 95% of my shooting in both handgun and rifle up to around 2,000 fps with no leading and good accuracy. In low pressure, low velocity stuff like the 45 ACP I use SWW +2% Sn at 8 BHN.

 

[Brad]

Hard bullets, undersized, at low pressure are a sure fire leading method. And I don’t mean mild leading, I mean the kind that gives keyholes from 38 specials within 50 rounds.

 

[Ian]

Nice, makes me wonder why I keep the linotype and babbitt around, and why so many insist on shooting the Lyman #2 or harder.

So many insist on shooting hard alloys for the same reason our wives cut the end off of a roast.

The toughest alloy I've ever had cause to use is approximately Lyman #2, and only in some instances.

 

[Ole_270]

I've got another 400 lbs or so of the range lead that was the basis of this alloy. It's been running 1.4-1.6% Sb on the samples I've sent BNE. It doesn't look like I'll run out anytime soon, especially since cooler weather will eventually get her and allow me to start digging the berm at the range again.
Thanks guys

 

[popper]

Hard bullets, undersized, at low pressure are a sure fire leading method. Not exactly. I shot 40sw PB undersized/really soft (~950 fps) and terrible leading - BLL blew off! ~36BHN PB (coated) at 2k fps (300AAC) with accuracy and NO leading, at bore size! Not that it is ever really needed (close to Cu solids). Soft alloys will 'slump' into the grooves, hard & small tend to cut into the grooves. Soft alloy tends to size smaller than hard. For revolvers I suspect the gap and forcing cone make a difference too. Basically, anything will work, just figure what is needed to make it work (target, HV, hunting, etc.). Like cooking, begin with basic recipe and modify till the results are correct.

 

[Brad]

My experience is based on .358 RN bullets I purchased for 38 special loads. They were cast from 6/2/92 alloy and had the typical hard lube. Leaded like crazy with any load.
I measured a few and holy crap, they ran .356!
My barrel had so much lead in it that Deer Run made me an offer

 

[Ian]

Undersized leads, period.

 

[CZ93X62]

Undersized leads, period.

That has been my experience. Fully-sized does not, with very few exceptions.

 

[JWFilips]

The commercial casters have to ship the bullets all over the place...... Commercial Hard Cast at BHN 18 means they will arrive at the destination in somewhat -bullet -shape! That is the only reason for "Commercial Hard Cast"

 

[fiver]

not the only reason for it, but it is part of why they use it.

 

[Rick]

That they use too hard of an alloy is understandable. What is not understandable is that they try to make their customers think it's a good thing and they are doing it for them.

 

[fiver]

well,,, you can't go round telling everyone your stuff sucks and expect to stay in business.