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Post by Junior on May 9, 2016 20:21:36 GMT -7
270 Grain
Firearm - Marlin 336 Primer - CCI #200 Powder - 40.0 Grains IMR-4895 Bullet - 270 grain Bullshop Stomper Case - Reformed LC 308 OAL - 2.585" Velocity - 2051 Notes - Bullet seated past crimp groove so that it will feed from the tube of the Marlin 336. Used 35 Remington crimp die to crimp to keep bullets from setting back because of recoil. Load Credit - SierraHunter
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beb
Bullet Head
Posts: 5
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Post by beb on Feb 13, 2017 18:41:45 GMT -7
Here's one that I like in the .358 Winchester:
A load for my Ruger 77 Mk II Frontier (16 1/2" barrel, 1 in 12" twist) - with forward mounted 4X Weaver scope.
Bullet: Accurate Molds 36-302DG gas checked, cast of linotype, and sized to 0.360"
Weight 278.5 grains, with GC and lube.
Brass: Hornady
Primer: S&B Large Rifle Magnum
Powder: Accurate Arms 4064, 38.5 grains. Groups are still good at 39 grains, but open sharply at 40.
Light roll crimp. Cartridge OAL 2.755"
1735 fps - average 3.1 MOA over a 30 shot database.
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Post by Bullshop on Feb 13, 2017 19:19:32 GMT -7
Have you found straight linotype to be brittle and shatter on impact with anything hard like bone?
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beb
Bullet Head
Posts: 5
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Post by beb on Feb 14, 2017 12:49:36 GMT -7
I have never shot an animal with linotype, so I must say that I don't know. Heat treated scrap alloy works just as well as the linotype in this load, with the advantage of being a good deal heavier - 298 grains or so (I cut the powder charge by 1/2 grain with these). I have heard reports that heat treated alloy performs better than linotype on game, but can't verify this. The load does need a hard bullet to shoot well.
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Post by Bullshop on Feb 14, 2017 17:06:29 GMT -7
Air cooled Linotype will rate a BHN-of 24 Quenched linotype depending on how hot it is when it hits the water as well as the temp of the water will go BHN-30+ Quenched COWW will go BHN-20+ depending on how long they age after quenching. I have experienced shattering with high antimony alloys like lino or monotype metals. The shattering can completely disintegrate the bullet into dust. With quenched low antimony alloys there can be some fracturing depending on the impact velocity but I have never seen complete disintegration of the bullet unless of course it hits rock or steel. On flesh and bone the more malleable low antimony quench hardened give the toughness for high pressure loads but do not shatter as high antimony alloys can and do.
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beb
Bullet Head
Posts: 5
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Post by beb on Feb 15, 2017 7:42:46 GMT -7
Very interesting. Linotype casts a lovely bullet, but I didn't know that it would turn to powder. That's because of city living - these days, just getting to the range is an outing for me. Woods and game are a memory. Should I ever have the privilege of wandering God's earth again, I'll load less brittle stuff into the magazine. Thanks for the info!
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Post by Bullshop on Feb 15, 2017 13:16:44 GMT -7
The type metals do cast very well because of the high tin content but they also have a high antimony content and that is what makes them brittle. Last year I purchased several ton of an alloy that is 98% lead and 2% antimony. This alloy when air cooled will rate a BHN of 8.5 to 9. The same alloy quench hardened will rate a BHN of 15 a few days after quenching. It is my view that not more than 4 to 5% antimony is needed in any alloy to make them quench harden sufficiently to handle any normal pressure/velocity a cast bullet might be used for. An alloy of 4 to 1 of COWW to linotype when quench hardened will rate a BHN of 24 within a few days of quenching and can go as high as BHN-30 after aging a couple years depending on the arsenic content in the alloy. This is why if you want to make really hard bullets from low antimony alloys we add a bit of shot to the mix. Shot contains arsenic for the purpose of increasing surface tension. The high surface tension is what makes the shot round when dropped from a distance into coolant such as a shot tower does. The shot is free falling long enough to harden enough that when it hits the coolant it will not deform and the high surface tension pulling equally in all directions is what makes the shot round. In bullet casting we want to avoid high surface tension because it impedes the free flow of the alloy into the cavity. The addition of tin helps reduce surface tension so improves the fluidity of the alloy and is why many folks add tin to their alloy because where technique may be lacking tin covers a multitude of sin. The high tin content in type metals is exactly why they cast so well because the high tin content makes those alloys flow like water.
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beb
Bullet Head
Posts: 5
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Post by beb on Feb 15, 2017 21:11:34 GMT -7
Your post caused me to dig out an old 1979 copy of the NRA publication "Cast Bullets", which includes an article by metallurgist Dennis Marshall, entitled "Stronger Bullets with less Alloying". After describing heat treating, complete with graphs and microphotographs that make my head spin, he says "very small amounts of arsenic from 0.005% to 0.5% enhance the hardenability of antimony alloys by a quite disproportionate amount", and concludes by stating "antimony is the principal hardening agent and is most useful in amounts not exceeding 6%". While this 12 page, footnoted article is perfectly aligned with your personal observations, I am quite impressed that you can much more clearly convey what it struggles to say, in just a single paragraph!
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Post by Bullshop on Feb 15, 2017 21:31:08 GMT -7
Thank you very much! I graciously accept the compliment. I believe it was Albert Einstein that said, " if you cant explain something you don't understand it"
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