% of tin--How do you mix your alloy?

[bbogue1]

I am wrestling with % tin in my COWW. I have been happy with Glen Frexyll's recommendation of a total of 2% tin. I'm finding tin is difficult to find at a decent price so I am wondering if 1% tin or maybe no tin added to my COWW. To get those great looking bullets, do you have a standard % if tin in your alloy? How do you decide?

[Outpost75]

1% tin will work fine. More than 2% is a waste of money.

[upnorthwis]

Depending on what you're using them for, straight COWW should work just fine. Tell us what you plan on shooting them in. COWW should work in any pistol or revolver and a lot of rifles. I shot cast in IHMSA/NRA silhouette for many years and never added anything to the mix. And for the record, I was INT/MASTER in nearly every category. If you only want a "great looking bullet", save that expensive tin for something else. Outpost75 types faster than me.

[quail4jake]

The only observation I've made about Sn with COWW is that adding 2% Sn results in higher BHN (at least in my trial). COWW as rendered was BHN 14 and COWW+2% Sn settles at BHN 17 at 7 days. I have noticed really great castability with the 2% Sn added especially in small boolits, had trouble with COWW not filling out bases well in .32 115 boolits which resolved by adding 2% Sn. All the big dogs tell you that over 2% Sn imparts no advantage and that has been my experience too except in the case of old fashioned 20:1 Pb:Sn alloy which lands at BHN 8 and casts very well, that's 5% Sn. FWIW...

[OS OK]

1 pound of Sn will increase the Sn content of 100 pounds of COWW's to 1.5%Sn...and that's more than enough for outstanding fill-out in your moulds.
So...for example, depending on whether you are casting 158 grain or 200 grain boolits, your cost is just 1 pound of Sn in 101 pounds of boolit metal and there is from 4,500~3,500 casts respectively.
If you are casting 250 grain casts you'll have 2,800 for the cost of that 1 pound of Sn and @ $16.00/pound your cost increase is $0.0057 per cast...not much heh?
Is it worth it? Depends on what you want...this is one of those things in life you can have your way!

[Larry Gibson]

Currently tin runs around $15 per pound but it can be had cheaper by finding pewter and solder at yard sales, antique shops, etc.

One pound of tin at 2% will do 50 pounds of COWWs. Fifty one pounds of alloy makes a lot of bullets. Even at $15 a pound is that really that expensive?

The real question is what quality of bullet do you want(?) and what do you want it for? Straight COWW will suffice for many wants and applications just fine. However, the alloy will be much better all around if you balance the antimony with tin. Primarily it will give a stronger alloy that also fills out better. You can then stretch that alloy by mixing with pure lead (SOWWs) mixing as much as 50/50 with lead which in essence gives you your 1% tin but with the tin balanced with the antimony. That alloy will most often prove excellent up through 1800 - 1900 fps with GC'd bullets, especially if WQ'd or HT'd, for most cast bullet shooting.

[brewer12345]

But some junk pewter on eBay or at a thrift shop. I average about 3 bucks a pound. Easy to do mini smelts and pour into small ingots.

[Ranger 7]

I never add Tin!

I simply collect Range Scrap, process in my Lee 4/20 bottom, pours into ingots.
When I cast bullets (9mm, 380, 45acp, 38 & 375) I empty the cast bullets into a bucket of water with a gallon milk container of frozen water.
Read out at 13.4 BN. Work great in all of the above calibers, at mid to upper loads, never max loads, for the past 12 years.

[JonB_in_Glencoe]

SNIP...

To get those great looking bullets, do you have a standard % if tin in your alloy? How do you decide?

I use 94-3-3 for Rifle boolits, It gives very good fillout, and as Larry explained so well, a balanced alloy is stronger/tougher.

I use COWW or COWW blended with soft scrap for pistol boolits, depending on the desired loads I plan to assemble. If for some reason I have severe fillout issues during casting, I will add tin, usually about a 1/4 lb to a 20lb pot (which is actually more like 15 lbs when it's straight COWW), that 1/4 lb addition is around 2%. I surmise that some of my COWW batches are lower in tin, than is typical, causing that fillout issue. But usually increasing the alloy temp as well as increasing pour rate to raise the mold temp will cure some fillout problems, especially if the COWW is blended with soft scrap...but that will frost the boolits, which isn't a big deal if you don't drop them out of the mold too soon.

[zomby woof]

I have lots of tin. I can tell you that 93*4*3 makes great boolits.

[brewer12345]

I have lots of tin. I can tell you that 93*4*3 makes great boolits.

Agreed. I toss in 3 to 4 percent tin in with COWWs for rifle boolits and they come out pretty nice.

[USSR]

I cast handgun bullets only. My tin content always runs somewhere between 2% and 3%. I tend to restrict the amount of antimony I use, not the tin.

Don

[MyFlatline]

Abbreviations drive me nutz,,Sn is two letters Tin is three. It cant be that hard guys...)

[quilbilly]

My favorite alloy for both rifle and pistol is 60% pure, 35%+ chilled birdshot (a hardener), with the rest tin.

[brewer12345]

My favorite alloy for both rifle and pistol is 60% pure, 35%+ chilled birdshot (a hardener), with the rest tin.

Just curious, is the shot hard to clean up to use in the casting pot? I am under the impression that lead shot is generally graphite coated and that seems like it would make a mess of the pot.

[GhostHawk]

Normally I like to run 50% COWW and 50% range scrap or soft lead. To which I will add 1-2 % tin/pewter.

I have some lino cast up in 300 gr bullets, makes it easy to add a bit more tin where needed.

I also finally after 3 years of looking hit a pewter score, 6.5 lbs for 11$ at the local second hand store.

I don't get too precise about it, but I have a pretty well developed thumbnail. It does a pretty good job of matching metal to need so far.

And a touch harder is easy to do with a little water drop instead of air cooled when needed.

Shop around, keep looking for good scores, in the meantime spend some cash if needed.

[Budzilla 19]

Pm sent to bbogue1.

[lightman]

I cast mostly with clip on wheel weights. The older weights had a little more alloy in them than the newer ones. I'm not sure how much different or when it changed. I got excellent bullets with older weights and I mostly get good fill out and good bullets with the newer weights which have less than 1% tin. So, if they fill out ok I run with it. If they don't fill out and juggling my temp and casting speed does not help, I add maybe 1% more tin. It seems like 1% works fine and 2% is great. More is not really needed although Lyman#2 had 5% and makes really great bullets!

[fredj338]

I almost never add tin to my range scrap for pistol plinkers. If I do, 1% is plenty for getting a mold to fill out.

[pls1911]

I am somewhat embarressed to think of my current stockpile of processed lead, and the hours we spent trying for a "perfect alloy".

Years ago while shooting IMSHA Silhouette, a buddy and I cast several hundred pounds of #2 ingots of a carefully concocted mix of lead, coww, rangelead and babbitt material fresh from the smelter.... everything we had on hand at the time.
In the ensuing 30 years, and diversions of life, roughly a ton of reclaimed roofing lead, several full roles of 24" lead flashing have provided a lifetime supply source of pure lead ingots.

I now arrange "a handfull" of ingots of each allow around the casting pot, mixing somewhere around 50-50 #2 and pure lead as I go.
The occasional problem can usually be cured with an ounce or two of tin in a 20 pound pot.

My output remains high, and segregated by weight bullets shoot wonderfully, and heat treat as hard as I care to go (up to 25+ bhn).
So, what have I learned?

If your alloy is pure, and somewhere in the ballpark of 50-50 COWW + lead or #2+ Lead, or simply COWW or Simply #2, you should do fine.
If your bullets are dropping clean sharp and pretty, you're likely close enough. Need 'em hard? Heat treat 'em.
Size right (fit), Lube right, gas check rifles, load, shoot, smile.

Don't over think it. Your time is better spent smiling.