Home Forums Hunting & Shooting BPCR 45-70 vs 45-90, -100, -110, ets

Please help me out here, I was always under the impression that a certain amount of tin added to lead bullets increased hardness and helped improve penetration by controlling the mushrooming of the bullet i.e. pure lead being soft it expanded too fast for reliable deep penetration particularly on thick skinned animals.

Marrty antimony is a hardener. Tin will add to hardness but tins main function to the alloy is better fill out while casting. Some guys use alloys that have antimony but most use a pure lead with tin content ie (40 to 1) parts lead to parts tin for blackpowder use. Having an alloy that you know the exact makeup of allows you to repeat it. Magnum Man

OK

Q.) Does Tin "Affect Hardness"

A.) YES, but only in a marginal sense, and it's addition has WAY more to do with "castability".

Q.) Is there a "Point of diminishing Return" with pure Lead / Tin alloys

A.) Yup, at anything richer than 16:1 you're just wasting tin,......on any measuring scale known, richer than 16:1 adds NO "Additional Hardness"

Q.) So why the term "Tinning" when we discuss "Soldering".

A.) Drive a bunch of overly "tin rich" down a barrel a bit to fast, and you'll learn why Sulphurics are used to FLUX "Solders" and how your "Leading Problem" can be self induced, a combination of 2 basic material characteristics

Q.) SO, why bother with TIN AT ALL ?

A.) CASTABILITY, FIRST AND FOREMOST, and than the kinda' NEAT ability to "fine tune" your "As Cast bullet diameter, when working in a new Bore size, or some oddball cartridge load development area.

Q. How about Antimony ?

A.) Great stuff, intriguing and totally unstable affects on bullet hardness, e.g. "Age Hardening",....v. "Age Softening"
KILLS Monks that use it to harden type, ands it's fumes WILL [bleep] you right up, too. Once it's in your BEST alloy pot,and on your ladles / molds, nothing short of a thermonuclear device will totally remove it.
Admittedly A damned VALUABLE (cheapo) way to sneak up on "Solids" performance in a CB.
REAL BPCR shooters tend to avoid the chit like the plague.

Q.) So, is there a good supply of "Pure Lead" and "Pure Tin" available, at this time ?

A.)Lead,.... No ,......and if you price out "Lab Grade" Lead (99.999 pure) you better be sitting down,....
Tin, Yes, but no longer anything approaching "Cheap".

Back tomorrow, .....and to discuss "The Wisdom of LARGE Batches, when blending BPCR Alloys"

Thank you both, this is exactly why I like reading these threads.
Plenty of good reliable advice from people who know what they are talking about.

very interesting stuff, all right. I deal with metals and alloys all day, but usually in steel & nickel alloys, so it is interesting to read of how they behave with lead and its alloying elements.

Maarty,Cross gave you the basic characteristics of the alloys. I'll try to give you the practicalities. lead/tin gives a very decent combination of the right amount of hardness and castability. Look, at BPC velocities, 20:1 is damn near the same as a solid in smokeless guns. I never could fathom why a guy would NOT choose a 458 Win Magnum solid for elk or buffler but would use a hardcast slug for the same critters. It WILL behave the same. When you use about a 30:1 lead/tin, you get penetration as good as a cannon shell AND decent expansion. Remember we are using massive bullets. for a 45 they are usually 520-550 grains. Now another facot sneaks in. I use paperpatched bullets for 99% of my shooting. A softer (30:1) alloy will allow the BP charge to "slug" (upset) the undersize( about .001-.002)bullet into the rifling very nicely. Match shooters who use gg slus generally want their slugs a mite harder but about 18:1 seems about right. If a hunter wants gg bullets,30:1 is still a good way to travel. Sized right and lubed up well makes for some pretty good critterkillers.

Here's a Sunday Morning "Tech Tip"

If you are wanting to make some REALLY nice, e.g. "Special" bullets, find yourself a roll of Harris Welco "Staybright" Low Temp Silver solder.


It's a Vacuum Chamber blended Alloy, 95% Tin, 5% SILVER, and not all that expensive. Brownell's calls it "Force 44" and charges the chit outta' ya' for it. Welding suppliers usually have the stuff at best pricing you're gonna find.

So, at that 95% Tin content, just make up or adjust to your normal blending ratios, factoring 105% Tin Weight, versus your normal 100%. You will NEVER cast prettier, shinier, and more uniform (by weight)bullets.

WERE I lucky enough to be going after an African or Asian Buff, or some such, I'd damn sure justify the little additional expense.

........and then of course, there's always the chance that one may occasionally have to deal with a pesky lycanthrope.

Best Regards, GTC

That's what I like!! Versatility!! Always good to be able to handle them thar werewolves!!

ET, Greg, thank you both for your recent posts. Knowing things and expressing them clearly are on occasion a bit of a challenge for me. Still not so old I can't learn a new trick now and then...if someone is willing to teach the class.