The micro-groove marlins are notorious for poor results with cast. People have got them to shoot but it takes a lot of experimenting with alloy, hardness, and bullet diameter.
Cast Bullets
- Thread starter 1899
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The micro-groove marlins are notorious for poor results with cast. People have got them to shoot but it takes a lot of experimenting with alloy, hardness, and bullet diameter.
The real trick to accuracy with Microgroove rifling is to be sure the bullet is at least two thousandths larger than the bore. Three thou is better. Accuracy with very little leading is much more likely, even with plain base bullets.
Try it, and give us a report back.
Ted
Try it, and give us a report back.
Ted
I've been using 180 RN sized to .309 and gas checked. Micro groove rifling is very shallow, I don't think its biting.
Try shooting them as cast, without sizing them to .309, and you will be pleasantly surprised.
Ted
Bullets that are too hard do break up easier. I like a bullet in the 18-20 BHN range maximum for hunting. Harder than that will break up easier. 18-20 BHN does seem to be a good compromise between flexibility toughness and hardness. I have had some really good results from heat treating cast bullets. They hang together well and they aren't brittle like super hard cast bullets are.
People get too fixated on hardness. They should be more concerned with bullet fit and sizing. It has been said before, but the first thing a cast bullet shooter should do is slug their barrel and that alone will solve 60% of any leading problem you have. Undersize bullets are the culprits behind most leading issues, but hardness usually gets the blame. A cast bullet .002" larger than groove diameter is a wonderful thing.
- Location
- Golden Lake
There's an article in the current issue of "Handloader" magazine that discusses cast bullets and micro-groove rifling. The author gets good results.
jethunter,
How do you find straight wheel weights for hunting? I would like to give some of these 285 gr 9.3s a try on bear this Spring. They were cold water quenched when cast, however that was over a year ago, so will have softened up a bit.
You have seen these pictures before.
You have much more experience in this than I, and would appreciate your candid opinion on using this bullet for hunting.
Thanks,
Ted
Thanks Jethunter.
Ted - According to my old Lyman manual that I bought from a used book store wheel weights will give you ~9 BHN. Going from memory, heat treating them in a 450F oven for 1 hour increases this to ~25 BHN.
At any rate I went by the local tire shop on the way home from work yesterday to see if they had some old wheel weights. I learned that this particular shop now only uses plastic coated steel wheel weights. They had a bucket full of old weights but they were almost all this newer "environmentally friendly" style coated steel versions. I'll have to call around to see if I can find some.
I've also been cruising some sites that offer custom molds - for example Accurate Molds. Lots of neat stuff but there are even more choices! Aluminum, brass or steel molds? Bore riding design or not?
Lol...I'm going to try and keep it as simple as possible, but there sure is a lot to learn if a fellow were to try and get really serious about this casting bullets hobby! I wonder if the answer to keeping it real simple isn't just using a very heavy for caliber bullet at moderate velocity, say 1200-1400 fps out of soft pure wheel weights without heat treating. You would have lots of momentum to keep that soft expanding bullet going. For example, Accurate Molds has a 355gr (wheel weight casting) mold for the 9.3
Anyways, it looks like fun and I think I'm going to at least give it a try.
Ted - According to my old Lyman manual that I bought from a used book store wheel weights will give you ~9 BHN. Going from memory, heat treating them in a 450F oven for 1 hour increases this to ~25 BHN.
At any rate I went by the local tire shop on the way home from work yesterday to see if they had some old wheel weights. I learned that this particular shop now only uses plastic coated steel wheel weights. They had a bucket full of old weights but they were almost all this newer "environmentally friendly" style coated steel versions. I'll have to call around to see if I can find some.
I've also been cruising some sites that offer custom molds - for example Accurate Molds. Lots of neat stuff but there are even more choices! Aluminum, brass or steel molds? Bore riding design or not?
Lol...I'm going to try and keep it as simple as possible, but there sure is a lot to learn if a fellow were to try and get really serious about this casting bullets hobby! I wonder if the answer to keeping it real simple isn't just using a very heavy for caliber bullet at moderate velocity, say 1200-1400 fps out of soft pure wheel weights without heat treating. You would have lots of momentum to keep that soft expanding bullet going. For example, Accurate Molds has a 355gr (wheel weight casting) mold for the 9.3
Anyways, it looks like fun and I think I'm going to at least give it a try.
jethunter,
How do you find straight wheel weights for hunting? I would like to give some of these 285 gr 9.3s a try on bear this Spring. They were cold water quenched when cast, however that was over a year ago, so will have softened up a bit.
You have seen these pictures before.
You have much more experience in this than I, and would appreciate your candid opinion on using this bullet for hunting.
Thanks,
Ted
That bullet looked like it performed darn well, and more so when you consider the velocity. I don't think you can ask for too much more actually. It didn't break up and it has some expansion to it which means it's got some toughness and it's not overly hard. I'd say you've got a pretty good bullet there. When you find a shot bullet that is a soup can shape - no expansion and the nose completely broke off that you start wondering if it's too hard. But even those will usually penetrate well.
Wheel weights can make good rifle bullets. There is actually quite a variation in ww lead, ranging from about 10 to 14 BHN. If you start with 12-14 BHN you can harden it to 16-18 with water dropping or heat treating. Some molds need a bit of tin added to ww lead to help fill out; depends on the mold and the ww alloy. I'll smelt my ww and then do a hardness test and decide if I need to add antimony or not.
WW are usually in the 10-14 BHN range nowdays. Maybe they were softer years ago but they average about BHN 11-12 BHN now days.
450F is a bit too hot for heat treating, good chance your bullets will start to droop at that temperature. You"ll know right away - there will be flat marks on the side of the bullet where it was touching the pan and some of them will be oval shape, At this point you throw them back in the pot and start again. Don't trust the temperature indicator on your stove, they can be off by 30 F or more. You need an accurate oven thermometer for heat treating to be effective. 425F is a good temperature for heat treating.
BigUglyMan
CGN Ultra frequent flyer
- Location
- New Scotland
I was thinking the same thing. As a knifemaker you have to take steel to critical (non-magnetic) temperature then quench it. Not sure how you manage to harden a lead-tin-antimony mix with temperature alone rather than adjusting the composition of the mix, but I'm not a metalurgist. I'd be interested to hear as well.
I'll look in the book when I go home and provide the explanation they give.
Edit - here is a link that has some good information on heat treating. There is a chart at the bottom of the page that shows the effect of using a convection oven.
Edit - here is a link that has some good information on heat treating. There is a chart at the bottom of the page that shows the effect of using a convection oven.
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You cook them in an oven and then quench in cold water. Works the same as water dropping but better. Results depend on the alloy. Antimony is the key ingredient and ww generally have enough antimony to respond well.
The Las Angelos Silhouette Club did some testing and a good write up on heat treating. I'll see if I can find the link.
Edit: here's the link to the LASC cast bullet site. Very informative website, btw. The link to heat treating is about half way down the page.
http://www.lasc.us/CastBulletNotes.htm
The Las Angelos Silhouette Club did some testing and a good write up on heat treating. I'll see if I can find the link.
Edit: here's the link to the LASC cast bullet site. Very informative website, btw. The link to heat treating is about half way down the page.
http://www.lasc.us/CastBulletNotes.htm
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I've heat treated about a ton of cast bullets and use a toaster over I got at a garage sale for $1. I only use it for cast bullets. It's very easy to do and very repeatable. Turn the oven on to what you think is about 400-450 degrees, you can use a thermometer if you'd like. Place 1-2 bullets in for about 1/2 hr-45min and see if they sloop or deform. If not you can turn up the heat and repeat till you see it just start to deform. Mark it on your stove just below that setting, it's the highest temp you can use for that alloy. You don't have to go to the highest setting, I've done it at a much lower setting and still hardened them. Once you have your max temp, set your bullets in the oven for 45 min- 1 hour in a tray. For a tray I use a large can from tomatoes, cut if off at about 1 1/2" deep, poke 2 holes in the side to loop through a coathanger wire for a handle. You're just making a small bucket for the bullets to sit in. After they've been in for 45 min(or 1 hour) remove them and RIGHT NOW drop them into a pail of cool water. Dry them off and final hardness occurs in about 24 hours. I use a Lee hardness tester and have treated bullets that were about 15 BHN to about 25+ BHN. It's very easy to do and once you have your tray made up you can redo this over and over. I'd rather not do it in the kitchen oven, you're dealing with lead alloys. You can probably get a toaster oven at a Salvation Army store for a few bucks. I can't count the number of bullets I've treated but it must be in the 10's of thousands. Best of luck, if you need any help you can PM me or just ask on the forum.
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...you can trim the waste meat away with a pocket knife just about double the size of the diametre of the .458...and they get pretty sick very fast (think about it more like trying to stop a freight car at 2 mph, not a phonograph needle loaded up to 9,000 fps)
View attachment 11185
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...you can trim the waste meat away with a pocket knife just about double the size of the diametre of the .458...and they get pretty sick very fast (think about it more like trying to stop a freight car at 2 mph, not a phonograph needle loaded up to 9,000 fps)
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...that's a really old Weaver 1.5x...and the patch is blue onion skin parchment paper...can't recall the thickness...but thin...bullet is put through a sizer and then patched and put through the sizer again...fun to shoot! This was using a few grains of Unique powder...about $.04/round...and my lube is from my own bees mixed with petroleum jelly...
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