Elasticity of tin?

[evoevil]

been looking into this also. Thanks for the info. I use WW with 25% pure lead ........ it just the way the mix worked out. I stopped water dropping. Mine being GC and PC also I think it will holds up to higher FPS while giving a good expansion.

[Tripplebeards]

1st try...caught the boolit in the fourth milk jug. It started out as 270 grains and ended up at only 124.3 grains. The widest part measured .780". It was shot out of my ruger 77/44 using 23.8g of W296. The jugs were set out about 20' or so from the muzzle. The boolit peeled back and lost all its PC(you can barely see the purple PC). I had no leading. Accuracy at a 100 yards wasn't impressive. My best group was 2.7" It was a pretty stout load. If I drop it down to 21-22 grains of Powder maybe I'd get better weight retention. I think straight ACCOWW with a little pewter would be a better option for full throttle rifle velocities. I'd like to see a lot better weight retention. I've come to a conclusion that 14 bh(coww PB hardness)...or harder is needed when hunting with devistators at rifles velocities(1675-1800fps) to keep good boolit weight retention.

[Tripplebeards]

Here's a good read with pics on different alloys used with the devistators just not at the higher velocities I'm pushing it...

http://castboolits.gunloads.com/show...-44-Devastator

[JonB_in_Glencoe]

Elasticity of tin?

In some of the readings I've done in here it seems that Tin(I'm using pewter) helps with keeping the hollow point pedals of the 44 mag devastators I'm casting from shearing off. I've tried pure lead with 6% pewter with a Bh around 6.5 at 1675fps and ended up with a completely flatten bullet that was about 1/4" wider than it started with and I'm guessing a little less than a 100g left from the original 270g. I couldn't catch my acccow 14 Bh that went through 8 jugs of wAter and kept cruising. I've seen pics of these caught by other members with the pedals sheered off. I mixed up 50/50...acccow that has a Bh around 14 and my soft lead with a Bh around 6. I also added 2% pewter. I figured this would be a happy medium for optimum expansion and still a good amount of weight retention for thin skinned whitetails. I plan on using these in my Ruger 77/44 and going to try h110 from 21 to 23g and see how my groupings are. I'm wondering if I would gain anything by adding, say a total of 6% or more of pewter in the idea of keeping my boolit pedals from shearing off?

I've always equated the term elasticity of a boolit alloy with "spring back" when a boolit is sized, and not necessarily the malleability or toughness.
http://castboolits.gunloads.com/show...-on-sizer-size

Some years ago, I did some shooting of HP boolits with different alloys and quickly learned there are too many variables for anyone to give me an answer to my question, which was similar to your question...although my question was less specific.

I will offer you a couple things to think about that I have learned. Maybe you already know these things? but I'll offer them anyway, in case it helps you as you experiment with alloys.

Pure lead (Pb) or Lead with pure Tin (Sn) are the most malleable, and will give the best expansion, but will also fragment or tear apart easier.

Ternary boolit alloys (alloys with Pb, Sb, Sn) will be 'toughest' when the Sb and Sn is balanced, as they form the intermetallic compound SbSn. Toughness is more than just hardness, a 'toughest' alloy is least likely to tear or break during expansion. Add to that, the level of balanced percentages would need to increase as velocity is increased.

Lastly, I don't have a real good grasp on all the details of the effects on a boolit alloy when adding trace amounts of Cu, except that it adds a bit of hardness, but if air-cooled that hardness might not be measurable right away, it should be noticeable in a few months...and from my measurements it reaches max at 6 months.

Oh, here is another good thread on toughness.
http://castboolits.gunloads.com/show...ntimony-Alloys

[fecmech]

IMO something you need to consider is the size of the HP in that devastator. I remember the HP in my .45 acp devastator was huge and they are basically designed to expand at pistol velocities. You are 300-500 fps over pistol speeds which would indicate a smaller HP with thicker walls to my mind.

[Tripplebeards]

After what I’ve read in the post I tagged above I’m going to download starting at 21gr and work up in .5 gr increments to 23g and load and test again in some softer media like wet newspapers. I’d like to get better than the current load which got a 2.7” 100 yard group. I think water is too harsh of a test. Even though it did shed a little over half it’s weight it did expand to almost double the diameter instead of the pedals braking off. It sounds like others have used the same 50/50 mix at rifle velocities (1700 FPS plus)with good results on whitetails. I casted these less than a week ago so I’m guessing they will harden a little more in a few weeks and I’ll test again.

I still might experiment with 94% acccow and 6% pewter and also a 3/4 mix of acccow and 25% pure with pewter added.

[Tripplebeards]

I just mixed 80% ACCOWW along with 20% pure and ended up adding 6% pewter. I casted up a batch and just finished PCing them. I could tell its a lot harder than my 50/50 as soon as it cooled just by scratching it with my fingernail. I'll give it a week to harden and test it. Within a week I'm sure it will be close to its end hardness. I tested my 50/50 w/2% pewter mix and it's still at 10.5 BH, the same as it tested a day after I casted it...and its been over a week now with no change. I'm hoping by adding in the additional pewter it will make it a little tougher and keep its pedals from shedding.

I just tested my new batch that I made this morning and it's already at a BH of 13.

I’m still planning on testing my 50/50 mix at lower velocities since it did expand to almost 2ce it’s diameter with a full powerhouse load.

[Lloyd Smale]

For HPs in low velocity guns like the 9s 40s and 45acp I use what I call my bubble gun alloy. In a 20lb pot I mix 17lbs of pure and 3lbs of clip on ww. No tin and no more antimony. It mushrooms as well or better then xtps and bullets recovered look like perfect mushrooms with very little weight loss. I do pc coat them so that they can be pushed to 800-1000 fps without leading.