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Post by sixshot on Jul 17, 2017 11:05:51 GMT -5
I've been sitting this one out & waiting for someone to explain the short comings or limitation of the 300 gr. solids, all 6 of them but no explanation. And this from a gun & caliber that has nailed quite a few Elephants! I'll go out on a limb here & say the 420 gr slugs were (my opinion) driven too fast & that "might" have caused the failure, of course we'll never know.
I do know that back in the early days of Handgun Silhouette we found out that too much speed was killing us on the 200 meter Rams, our bullets were breaking up before we had enough "dwell" time for the bullet to push those full footed Rams off the rail. When we slowed things down a bit, we got a more harmonious out come.
Also, Craig, I thought those 3 bullets you showed a while back were superb after all they went through on that big animal, don't see how anyway could find fault with how they performed, I'd gave them an A for doing what they were designed to do.
Dick
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Post by jfs on Jul 17, 2017 13:21:16 GMT -5
Its been awhile since I`ve read about the "hammer smash" method for testing the hardness of a cast bullet... I know very little about the making of cast bullets but that sounded as good a way as any to see if it would hold up after reading so many years ago.... 
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Post by magnumwheelman on Jul 17, 2017 14:00:07 GMT -5
I personally have a Saaco hardness tester  |
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Post by bradshaw on Jul 17, 2017 19:05:31 GMT -5
I've been sitting this one out & waiting for someone to explain the short comings or limitation of the 300 gr. solids, all 6 of them but no explanation. And this from a gun & caliber that has nailed quite a few Elephants! I'll go out on a limb here & say the 420 gr slugs were (my opinion) driven too fast & that "might" have caused the failure, of course we'll never know. I do know that back in the early days of Handgun Silhouette we found out that too much speed was killing us on the 200 meter Rams, our bullets were breaking up before we had enough "dwell" time for the bullet to push those full footed Rams off the rail. When we slowed things down a bit, we got a more harmonious out come. Also, Craig, I thought those 3 bullets you showed a while back were superb after all they went through on that big animal, don't see how anyway could find fault with how they performed, I'd gave them an A for doing what they were designed to do. Dick ***** Dick Thompson talking about DWELL TIME is an argument I had with bullet engineers in the late 1970’s: that lead hardened to brittleness blew up on silhouettes, and velocity aggravated the problem. I may have coined the term “dwell time” during these discussions. From what I saw on the firing line, bullets from same batch might exhibit varying degrees of brittleness. Under ostensibly identical conditions----same load, same gun, same targets, same range, same time & day----some blew up while others did not. Suggesting there may be enough variation between bullets of the same batch that they all occupy a red zone in which some fail and the others are close to failing, even though we don’t see it. FORGIVENESS is a term I picked up while hunting with chronograph scientist Ken Oehler and it applies specifically to a bullet having the performance cushion to do its work. David Bradshaw |
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Post by tradmark on Jul 17, 2017 23:25:13 GMT -5
Great insights bradshaw. Ive always thought that there was alot of fussiness with cast on the toughest situations like big bones. I did the hammer test on the 440 gr 50 cal bullets last october. Yet the one used failed. It passed thru but did no damage and the exit hole was as though someone poked a pencil thru the hide. How does one know the integrity of a bullet. Hardness is only one part of the equation. How does one know how the bullet u actually shoot is going to have the proper lead integrity.
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Post by sixshot on Jul 17, 2017 23:58:35 GMT -5
Wheel weights back in the early days like the 70's-80's, etc. had a higher per cent of antimony, which was the curse & cure for bullet hardness. As the bullets age they get even harder & to make things even worse many shooters were water quenching! So now we had a bullet that many times had about double the antimony of today's wheel weights, guys were water quenching, aging them, & trying to drive them to even higher velocities thinking that's what they needed to take off those 3%$@&^ Rams! What everyone was doing was going in the wrong direction! Harder, more brittle bullets at faster velocities so a lack of "dwell time".
Tin, although not nearly as good as antimony for a hardener allowed the more experienced caster to make a bullet more suitable for Silhouette shooting. The guys shooting 20-28 BHN bullets at top speeds in their 44 magnums were blowing top straps off their Super Blackhawks & many never did figure it out. A more ductile bullet allows more dwell time before bullet break up giving the bullet time to deliver the momentum necessary to cleanly topple the troublesome Rams. If David would have spoken up earlier he might have saved several guys from destroying some very nice sixguns! Nice to have him on here with his wealth of knowledge, very unique to have someone with so many direct contacts to the shooting industry, plus be a World Champion!
Dick
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Post by bula on Jul 18, 2017 7:39:02 GMT -5
Amen.
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Post by boolitdesigner on Jul 18, 2017 8:57:13 GMT -5
The king of toughness at low velocities is pure lead.... hit a bullet made of it with a 2 lb. hammer and it squashes without blowing apart. Lead/tin alloys move velocity up the scale. Next are sub 2% antimony / 1/4% tin alloys that are heat treated. After that are copper bearing alloys. Go on and the alloys won't expand, but act like the mythical krytonite. High % antimony alloys are brittle (especially linotype) and explode on hard surfaces. All of these things have a place in your shooting agenda, just pick wisely where to use them.
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Post by sixshot on Jul 18, 2017 12:26:14 GMT -5
Told you!
Dick
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Post by glynn410 on Jul 25, 2017 9:23:24 GMT -5
late to post just saw it Back in the 70's Jeff Cooper wrote about dwell time -- He used a safe door -- hit it hard break hand-- hard push and the door will close-- his words- -- used to explain why the Brits thought the 200 gr 38 special was better on the Nazi than a more normal load
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